Learning Center
Plans & pricing Sign in
Sign Out



									                                                                                Reproduction:      binary fission (splits in two)
            BIOLOGY II REVIEW                                                   Beneficial:        decomposers of matter, in digestive system, nitrogen-
          High School Graduation Test                                           Harmful:
                                                                                                   can cause diseases like strep throat, pneumonia
                           LINNAEAN SYSTEM
          In the mid-1700’s, Carolus Linnaeus developed a new                   Examples:          Most unicellular organisms - protozoa, amoeba,
classification system that revolutionized taxonomy. He suggested that                              zooplankton, euglena, paramecium, and algae
organisms be classified with other organisms that had similar structures.       Characteristics:   Animal-like organism, distinguished by method of
Organisms are known by their common name, such as red maple.                                       locomotion, eukaryotes, mainly microscopic, single
Organisms have been given a scientific name, the genus followed by the                             celled or multicellular; some are autotrophic (algae)
species. The genus and species for the red maple tree is Acer rubrum. The                          and many are heterotrophic (protozoans)
genus begins with a capital letter and the second name is always lower case.    Structures:        flagella, capsules, cell organelles, membrane bound,
All scientific names are written in Latin, and are italicized or underlined.                       some are photosynthetic
                                                                                Growth:            cell membrane, availability of food set growth limit.
         A classification key can be used as an aid to identify organism. It    Reproduction:      asexual or sexual
uses an organisms general characteristics and special features to find its      Beneficial:        some are harmless
appropriate placement.                                                          Harmful:           sleeping sickness, malaria
                                TAXONOMY                                        Examples:          mushrooms, bread molds, slime molds, rusts and
                                                                                                   smuts, yeast
         Scientists these days study chromosome structure, reproductive         Characteristics:   Animal-like organism, cannot move, eukaryotes,
potential, biochemical similarities, and embryology to determine the                               mainly multicellular, parasitic, symbiotic,
relationships among organisms. The classification levels are:                                      heterotrophic,
                                                                                Structures:        root-like, caps, filaments
     Kingdom-Phylum-Class-Order-Family-Genus-Species                            Growth:            based on food source and availability
                   (King Philip Came Over For Great Spaghetti)                  Reproduction:      asexual, sexual
                                                                                Beneficial:        yeast, penicillin, decompose organic material
                                 KINGDOMS                                       Harmful:           cereal rusts, ringworm, athlete’s foot,
MONERA                                                                          PLANTS
Examples:               Bacteria, blue-green bacteria, and other                Examples:          All multicellular plants - Mosses, liverworts,
                        microorganisms that lack nuclei                                            hornworts, ferns, gymnosperms (pine cone plants),
Characteristics:        prokaryote, microscopic, lives as a single cell or in                      angiosperms (flower-bearing plants)
                        colonies in water. Most are autotrophic (producers),    Characteristics:   eukaryotes, mainly multicellular, can’t move,
                        a few are heterotrophic (consumers)                                        autotrophic
Structures:             flagella, capsules                                      Structures:        cellulose cell walls
Growth:                 cell membrane and availability of food set growth       Functions:         based on cell and tissue chemistry
                        limit; keep moist and warm for optimal conditions       Systems:           all present and functioning

                                                                                                            Lakeside High School Science Department
Growth:                based on hormone action                                    bryophyte that is above the ground gets its water from the air through its
Reproduction:          asexual, sexual by spores, seeds, flowers, and cones       leaves. Bryophyte leaves are usually only two cells thick.
                                                                                           The life cycle of the bryophytes exhibit alternation of generation.
ANIMALS                                                                           This means that they alternate between gametes and spores. The
Examples:              All multicellular animals - Invertebrates (sponges,        gametophyte produces gametes (sex cells) by mitosis. During fertilization,
                       jellyfish, coral, sea anemones, planarian, fluke,          the gametes fuse. The resulting zygote grows into a sporophyte, which
                       tapeworm, hookworm, earthworm, mollusks, starfish,         produces spores by meiosis. When the spores germinate, they develop into
                       insects, crustacean); vertebrates (fish – cartilaginous    the new gametophyte generation. In all bryophytes, the gametophyte
                       and bony); amphibians – frogs, salamanders; reptiles       generation is the dominant generation. The plant you are used to seeing is
                       – snakes, lizards, turtles; birds; and mammals             the gametophyte because the plant spends the majority of its life in this
Characteristics:       eukaryotes, multicellular, heterotrophic, most are         generation.
                       motile at some point in their lifetime                              There are three classes in phylum bryophyta: mosses
Structures:            all present and unique to the organism                     (Muscopsida), liverworts (Hepaticopsida), and hornworts
Functions:             based on nutrition, cell and tissue chemistry, and         (Antherocerotopsida
                       individual demands
Systems:               all present and functioning
Growth:                based on hormone action and nutrition                                                VASCULAR PLANTS
Reproduction:          asexual, sexual
                                                                                            Plants with vascular tissue are called tracheophytes. They have
                                 PLANTS                                           true roots, stems, and leaves. They have an internal network of tubes that
                                                                                  carry water, nutrients and glucose made from photosynthesis throughout the
         One of the major ways that land plants differ is the way they            plant.
transport water and nutrients throughout the plant body. The majority of                    The roots absorb water and nutrients from the soil and they anchor
land plants have an internal system of connected tubes and vessels called         the plant. The roots also store food that was made in the leaves. The stem
vascular tissues. These plants, called vascular plants, are the plants that you   contains vascular tissue that transports substances between the roots and the
are the most familiar with –maple trees, grasses, roses, and house plants.        leaves. The stem also supports plant growth above the ground. It is the
Vascular plants have roots, stems, and leaves.                                    backbone of the plant. There are two types of vascular tissue: xylem and
     The other group of plants is called bryophytes. They lack vascular           phloem. Xylem transports water and minerals absorbed by the roots up to
tissue. They transport water and nutrients by osmosis and diffusion.              those parts of the plant that are above the ground. The phloem carries sugar
                                                                                  and other soluble organic materials produced by photosynthesis from the
                                                                                  leaves to the rest of the plant.
                        NONVASCULAR PLANTS                                                  The leaves use sunlight, water, and carbon dioxide to carry out
                                                                                  photosynthesis. They also transport the food they produce to the rest of the
         Bryophytes need a lot of water to survive. Remember that they            plant in a process called translocation. In addition leaves exchange gases
transport materials by osmosis and diffusion. This requires a lot of water.       and water vapor with the atmosphere. The outside of the leave is covered
Almost all bryophytes are small plants and they grow close to the ground.         with a waxy layer that slows the evaporation of water from the leaf. The
Gravity can restrict the processes of osmosis and diffusion.                      waxy layer covers the epidermis, a single transparent layer of cells. The
         Bryophytes do not have true stems, leaves, and roots. What you           epidermis has openings called stomata. Each stomata has a guard cell on
think are their “roots” are actually rhizoids. They anchor the plant to the       each side. The guard cells change shape to control the exit and entry of
ground, but they do not absorb water like real roots do. The part of the          water and gases. Most guard cells are located on the underside of the leaf

                                                                                                                 Lakeside High School Science Department
where the surface is shaded. Ninety percent of the water that enters the
roots is lost through the leaves in a process called transpiration.              ANGIOSPERMS
          The middle portion of the cell is called mesophyll. The cells of the             Angiosperms are flowering plants. They produce seeds enclosed
mesophyll contain the chlorophyll and other pigments. Vascular bundles           in fruits. (Gymnosperm seeds are uncovered in their cones.) Angiosperms
extend into the tissue of the mesophyll. They are seen in the leaves as          are deciduous plants. That means that they lose their leaves every fall.
veins.                                                                           Angiosperms produce seeds with a cotyledon (seed leaf) inside. A
          The vascular plants can be divided into those that have seeds and      cotyledon provides food for the plant embryo in the seed when it begins to
those that have spores. Ferns, horsetails, whisk ferns, and club mosses all      grow.
have spores. All other plants have seed – either in a cone or in a fruit.                  Angiosperms can be divided into one of two groups. This group is
                                                                                 based on characteristics of their seeds: monocot and dicot. Monocots are
                                                                                 plants with only one cotyledon. Monocots also have vascular tissue that is
FERNS                                                                            scattered in separate bundles throughout the stem. The leaves have parallel
         Ferns are seedless plants that contain vascular tissue. Other           veins and the root system is fibrous with string-like branches.
seedless plant groups include whisk ferns, horsetails, and club mosses.                    Dicots have two cotyledons. Dicots have vascular tissue arranged
Ferns have underground rhizomes (underground stem) that produce roots.           in a circle around the outside of the stem. The leaves have net-like veins.
Each fern frond has a stem (called a stipe) many leaf blades that make up        The root is a large central taproot.
the frond. Fern fronds spread out over a large area and so ferns are able to
survive in dim sunlight.
         The life cycle of the fern has the sporophyte generation as the
dominant generation of the fern. The fern fronds produce spores, which are
released and grow into the gametophyte. The gametophyte then produces                                         REPRODUCTION
eggs and sperm to produce the sporophyte.
                                                                                            Vascular plant life is different from non-vascular plant life.
                                                                                 Nonvascular plants spend the majority of their life in the gametophyte
GYMNOSPERMS                                                                      phase. In vascular plants, the sporophyte generation is the dominant
          Gymnosperms are one of two groups of vascular plants.                  generation. The sporophyte is physically larger and shows more complex
Gymnosperms produce their seeds in cones and generally keep their leaves         development.
throughout the year (evergreen). There are four groups of gymnosperms                       The reproductive cycle of a conifer involves separate male and
alive today – Cycads, Gnetales, Ginkgoes (1 species), and Conifers.              female cones that are grown on the same tree. The male pollen cones
          Conifers means “cone-bearer”. Pines, spruce, fir, and other            produce the pollen grains. The female seed cones contain egg cells. Both
conifers are characterized by their stiff cones and needle-like leaves.          pollen and eggs are gametophytes. When the egg cells mature, the female
Conifers can thrive in harsh conditions because they have special                cells produce a sticky sap that traps the pollen grain. The pollen grain
adaptations. Their needles are covered in a hard waxy cuticle and have little    produces sperm, which fertilize the eggs. A conifer embryo develops,
exposed surface area. This means that they do not lose much moisture.            enclosed in the seed.
They shed their needles throughout the year instead of once a year. They                    Reproduction in angiosperms is different. All angiosperms
send their roots out into a wide area of soil instead of deep into the soil.     produce flowers. Some flowers have both male and female parts and some
This allows them to survive in areas where the soil is not very deep.            have just one sex. The flower attracts insects for pollination and thus
          Cycads live mostly in the tropics and look like palms, but are not     fertilization to make a seed. After fertilization, the flower petals die and the
related to them. The order Gnetales includes trees and woody vines. The          remaining flower structures form a fruit. The fruit protects the seed and
Ginkgo tree is the last species of a once widespread group of plants.

                                                                                                                  Lakeside High School Science Department
helps to disperse them in various ways. Then, an animal eats the fruit and                  Asexual reproduction can be accomplished naturally through
leaves the seed in its feces elsewhere.                                           vegetative propagation. This means that the plant sends out runners or long
                                                                                  modified stems (rhizomes) and grows new plants from these parts.
                                                                                            Artificial propagation involves things like cuttings and graftings.
SEXUAL REPRODUCTION                                                               With cuttings, pieces of stem are cut from the parent plant and kept in soil
          In plants that produce them, the flower functions in sexual             or water until roots grow. Then the plant is placed in soil to grow. Grafting
reproduction. Flowers consist of modified leaves. The essential flower            is a method used to propagate fruit trees, roses, and grapes. Sections of one
parts are the ones that produce gametes and carry out sexual reproduction.        plant’s stem are cut and attached to another plant’s stem that is already
These include male parts called stamens and female parts call pistils.            rooted in the soil.
          Most flowers have three, four, or five stamens. The thin stem-like
portion of a stamen is called the filament. Pollen is produced at the tip of                                         SEEDS
the filament, generally in an oblong structure called the anther. Most
flowers have a single pistil. The pistil contains three parts. The swollen                  Seeds gave the animal world a new high-energy food source. They
base of the pistil is called the ovary. Within the ovary, one or more ovules      provide food for mammals that need lots of food to help maintain their body
produce the egg cells. The slender middle part of the pistil is called the        temperature. People have depended upon angiosperms for food, lumber,
style. At the tip of the style is the stigma. The stigma produces a sticky        fibers, clothing, and medicines.
substance to which pollen grains become attached.                                            The development of plants that have seeds really helped plants to
          During pollination, pollen grains stick to the top of the stigma.       survive in a variety of places. Seeds can lie dormant (asleep) if the
From there, the pollen grain grows a pollen tube down through the style to        conditions aren’t right for growing. Some seeds, because they have burrs or
the ovary where it fertilizes the egg.                                            stickers, can travel a long way on animals or in the wind before developing
          In cross-pollination, the pollen from one flower sticks to insects,     into a plant. This spreading of seeds, called dispersal, is good for plants. It
which in turn deposit, it on other flowers. In self-pollination, the pollen is    helps to spread the plant’s genes over a wider area.
transferred to the stigma of the same flower. In the anther and the ovary,
cell division takes place, which reduces the number of chromosomes in half.
          Animals, wind, and water all transport pollen from flower to
flower. The nonessential flower parts are modified to aid the specific type                                 INVERTEBRATES
of pollination a plant undergoes. In flowers that are pollinated by animals,
the stem and receptacle hold the flower out where its colors and scent are                  The major difference between animals and plants is that animals
most obvious. Some flowers produce nectar, a sweet liquid.                       can move. Animals cannot produce their own food so they must move to
          Fruits are formed when the egg is fertilized and the ovary begins to   find it. The arrangement of body parts is related to how a particular animal
swell and ripen. It changes color and becomes fleshy or dry. Animals eat         species meets the challenges of living, which includes gathering food,
the fruit and pass the seed out to new places through their waste.               protecting itself, and reproducing. Differences in body structure are useful in
                                                                                 classifying animals. Invertebrates make up 97% of the animal kingdom.
ASEXUAL REPRODUCTION                                                             There are 15 invertebrate phyla and some of them will be discussed below.
           Many plants can produce new plants without the aid of
fertilization.. Asexual reproduction is common in strawberries, potatoes,         Phylum Porifera
irises, spider plants, and grasses. Remember that any plant produced                        Sponges have the simplest body organization of any family. They
asexually has the same genes as its parent plant.                                 have no head, mouth, or any organized systems like digestion and
                                                                                  circulation. The cells are not organized into tissues and organs. They live
                                                                                  in shallow seas. They are all shapes and sizes, as well as colors.

                                                                                                                  Lakeside High School Science Department
         They do not move around, attaching themselves to a rock, shell, or        generally involves two ore more hosts. They reproduce both sexually and
other substance. They feed by filtering food and nutrients out of the water.       asexually.
Their bodies consist of two layers of cells with a jelly-like layer in between.              The class Cestoda includes the tapeworms. Tapeworms live in the
They have skeleton framework made of spicules - interlocking spikes of             intestines of vertebrates where they feed by absorbing food that has already
calcium or spongin - a flexible protein.                                           been digested by their host. Tapeworms have no mouth or digestive system
         Sponges can regenerate lost parts. They can reproduce themselves          of their own. They reproduce either sexually or asexually.
from fragments. They are hermaphrodites - one sponge produces the sperm
and the eggs. Sperm from one sponges are carried to another sponge by              Phylum Nematoda
current.                                                                                     This phylum includes roundworms, also called nematodes.
                                                                                  Different types include Ascaris (intestinal roundworm), hookworms, trichina,
Phylum Coelentarate (also known as Cnidaria)                                      and pinworm. They have tubular bodies and have a digestive tract open at
          Coelenterates are bag-like animals with long flexible tentacles.        both ends. Most roundworm species have separate males and females. They
Most live in sea water, but hydras live in freshwater. Coelenterates include      have three tissue layers.
jellyfish, sea anemones, and corals.                                                         Most roundworms are parasites. They feed on plant by sucking the
          Coelenterates have a digestive gut with only one opening. They          juices from them. They can infect humans, usually from poor sanitation and
have radial symmetry (Symmetry where body parts are arranged around a             cause diseases. These roundworms are pinworms, hookworms, or intestinal
central point - like a wheel.) Their bodies consist of two layers of cells,       roundworms. Trichina infects pigs and can cause trichinosis in humans who
separated by a jelly-like substance.                                              eat raw or undercooked pork.
          They also have special stinging cells called cnidocytes. They are
located in the tentacles which circle the mouth. The stingers paralyze and         Phylum Annelida
lasso small prey. Coelenterates do not have a central nervous system or                      This phylum is the segmented worms - they have bodies that are
brain. They have a nerve net that allows from coordination and some               divided into a series of segments which often look like visible rings on the
simple movements. Reproduction of coelenterates involves an asexual               outside of the body. They are also called annelids. They include earth-
cycle and a sexual cycle.                                                         worms, leeches, and a variety of marine worms.
                                                                                             They have three tissue layers and a body that has bilateral
Phylum Platyhelminthes                                                            symmetry. Annelids have a true coelom (internal organs are suspended by
         This is the group of flatworms. There are three classes -                double layers of a membrane). They have two sets of muscles which allow
Turbellaria (non-parasitic), Trematoda (parasitic), and Cestoda (parasitic)       them to move more efficiently than other worms. Annelids also have a more
They have a digestive cavity with only one opening. They have no                  complex circulatory, nervous, and respiratory systems than other worms.
circulatory or respiratory system.                                                They have a closed circulatory system. They “breathe” through their skin,
         Turbellaria includes the most common flatworm, the planarian. It         taking in oxygen and giving off carbon dioxide. They have a ventral nerve
has a simple nervous system. It eats dead animals or slow-moving                  cord and they are hermaphrodites.
organisms. Planarians are hermaphroditic and can reproduce sexually or
asexually. It reproduces asexually by growing a new tail for the head part         Phylum Mollusca
and a new head for the tail part.                                                            This phylum is the soft bodied mollusks. They live in fresh as
         The Trematoda class includes flukes. Flukes are parasites and            well as sea water. They come in a variety of sizes Many are protected by
pose a serious health problem. Many can cause serious and even fatal              one or more shells. They are classified according to what kind of shell that
diseases. They live off the fluid of their host (blood or mucus). Most flukes     they have. They include the two-shelled mollusks (clams, scallops, oysters),
are endoparasites and live inside the body of their hosts. Their life cycle       one-shelled mollusks (snails) and no-shelled mollusks (squid, octopuses,

                                                                                                                  Lakeside High School Science Department
            Mollusks have bilateral symmetry and they have a true coelom.                     Insects are the only arthropods that can fly. They are both
They have three distinct body parts - head-foot, visceral mass, and mantle.         beneficial (pollination) and harmful (crop destroyers). They have three
Clams obtain both food and oxygen from the water that flows through their           distinct body parts and three pairs of legs. They include grasshoppers,
bodies. They are filter feeders. They have gills that absorb the oxygen from        crickets, termites, aphids, flies, mosquitoes, butterflies, moths, beetles, ants,
the water. They have an open circulatory system and a three chambered               wasps, and bees. Trachea carry oxygen to the body cells. They have an
heart.                                                                              open circulatory system. Grasshoppers have male and female sexes.
            The Gastropoda class includes snails and slugs. They have a more
advanced nervous system and do not have a ventral nerve cord. They have                                         VERTEBRATES
an open circulatory system and are hermaphrodites. Snails that live in water
breathe through gills. Land snails breathe through a network of blood               Phylum Chordata
vessels in their body.                                                                        This phylum is the most complex of all animals. The vertebrates
            The Cephalopoda includes squid, octopus, cuttlefish, and nautilus       (animals with backbones) make up the largest subphylum in the phylum
(the only one with a shell). They have a closed circulatory system and a well       Chordata. At some point in their development, all chordates possess four
developed nervous system with a complex brain. The central mouth has jaws           distinctive structures: a notochord, a nerve chord, gill slits, and a tail.
and it is surrounded by tentacles. They all live in the ocean and are                         The notochord is a long firm rod that extends along the back of the
carnivores. Cephalopods have separate sexes and have internal fertilization.        animal’s body. In vertebrates, the notochord is present in the embryo and is
                                                                                    later replaced by a backbone. The hollow tubular nerve chord runs the
 Phylum Echinodermata                                                               dorsal length of the animal, just above the notochord. One end will become
            Echinoderms are spiny-skinned and include starfish, sand dollars,       a brain. Paired openings in the throat are called gill slits. In fish, the gill
brittle stars, and sea urchins. They live only in marine habitats. Echinoderms      slits serve to get oxygen into the body. Most adult chordates have tails.
have an endoskeleton that is covered by a thin skin. They are considered the                  There are three subphylums in the chordata phylum. Urochordata
most advanced form of invertebrates and are classified closest to vertebrates       include sea squirts. Cephalochordata includes a thin fish-like animal called
due to a larva stage that is bilaterally symmetrical. They are radially             the lancelet. The third subphylum is Vertebrata.
symmetrical. They have no brain. They breathe through skin gills that are
protected by the spines.                                                            Subphylum Vertebrata
            Most reproduce sexually depositing sperm and eggs into the water.                 Vertebrates have a strong flexible backbone. Three classes live
A few species are hermaphroditic. The starfish has a remarkable ability to          entirely in water - jawless fish, cartilaginous fish, and bony fish.
regenerate body parts.                                                              Amphibians are adapted to life on land as well as the water. Reptiles and
                                                                                    mammals are primarily land animals. All but a few birds can fly.
 Phylum Arthropoda                                                                            Vertebrates have a number of characteristics in common. They
           The Arthropod phylum has more species than any other. Three              have bilateral symmetry. The major sense organs are located in the head.
 quarters of all species on earth are insects. Their great success is due in part   All vertebrates have a closed circulatory system and a coelom (large central
 to their body structure. They are characterized by having jointed                  body cavity that contains the important organs). They all have an
 appendages, a segmented body, and an outer skeleton (exoskeleton). It is           endoskeleton which supports and protects them. A distinctive feature of the
 made of chitin. They have a well developed open circulatory system with a          skeleton is the backbone - vertebral column. The endoskeleton can be made
 long dorsal tube for a heart. The nervous system consist of two long ventral       of cartilage or bone. They have pairs of muscles that work in opposite
 chains of nerves and a simple brain.                                               directions to push and pull the bones.
           The five major classes of Arthropods are insects (, arachnids                      Their bodies are covered with scales, skin, feathers, or hair. There
 (spiders, scorpions, ticks, mites), crustacean (crayfish, lobsters, crabs,         is contractile tissue attached to the bone or cartilage. They have a digestive
 shrimp), Diplopoda (millipedes), and Chilopoda (centipedes).                       tube that goes from mouth to anus. They have gills or lungs for breathing

                                                                                                                     Lakeside High School Science Department
and have a closed circulatory system with two-, three-, or four-chambered       their nervous system. They have separate sexes and have external
hearts. They have arteries to take the blood from the heart and veins to take   fertilization. Amphibians include frogs, toads, and salamanders.
it back to the heart.                                                                      In frogs, the young are called tadpoles and live in the water. The
          Their excretory (waste) system consist of kidneys, and associated     tadpoles go through metamorphosis, or change, as it develops into an adult.
tubes. Heir nervous system includes a spinal cord, brain, nerves, and sense     A tadpole begins life with a short tail and breathes through gills. Gradually
organs. There are male and female sexes.                                        it develops arms and legs and its tail begins to disappear. The lungs replace
                                                                                the gills and the frog leaves the water.
Class Agnatha
          The only two surviving members of this class are the hagfishes and    Class Reptilia
lampreys. They do not have jaws but use a sucker-like mouth to latch onto                Reptiles were the first animals that were truly independent of the
their prey. They have smooth, cylinder-like bodies with flexible skeletons      water. They do not need to keep their body moist for their skin is thick and
of cartilage. They have a heart with two-chambers and are ectothermic           covered with scales. They do not need to return to water to have babies for
(cold-blooded).                                                                 their young are laid in eggs. These eggs hold food for the embryo to live
                                                                                off of while it is growing.
Class Chondrichthyes                                                                     Some are herbivores and some are carnivores. They have strong,
          These are the cartilaginous fishes. Their skeletons are made of       bony skeletons and their feet have toes with claws. They have well-
cartilage. They have hinged jaws lined with rows of teeth. Their skin is        developed lungs and a three chambered heart (except for crocodiles). They
covered with tiny pointed teeth and it makes their skin feel like rough         are ectothermic. The reptile’s nervous system is similar to that of
sandpaper. They have gills and a two-chambered heart. They are                  amphibians and they have a small brains.
ectothermic. They have separate sexes and the eggs are fertilized inside the             Reptiles include the extinct dinosaurs, turtles, tortoises, alligators,
fish. They are carnivores (meat-eaters). The class includes sharks, rays, and   crocodiles, lizards, and snakes.
                                                                                Class Aves
Class Osteichthyes                                                                        This is the class of all birds. Birds arose from reptiles and they
         Most of the world’s fishes are in this class. They have skeletons      grew feathers instead of scales to insulate themselves. The feathers
made of bone, and have jaws and scaly skin. They get their oxygen from          distinguish birds from other classes of vertebrates. Birds are endothermic -
the water through gills. They have a swim bladder to help with buoyancy         warm-blooded - their body temperature remains constant. They have a
and a two-chambered heart. They are ectothermic. They have separate             four-chambered heart.
sexes and the eggs are fertilized outside the body.                                       They have wings and can fly. The body is divided into a head,
                                                                                neck, trunk, and tail. They do not have teeth - they have a horny beak.
Class Amphibia                                                                  Their front limbs are modified into wings. They lay eggs and incubate them
          Amphibians live on land and in the water. They have internal          in the nest.
lungs that are not very efficient and they also get oxygen through their                  There are four common bird types: flightless birds (penguins,
moist skin. They keep their skin moist with a mucus and they can never          ostriches), water birds (ducks, geese, swans), perching birds (sparrows,
venture too far from water. They return to the water to lay their eggs and      robins), and birds of prey (hawks, eagles, owls).
their young pass through a larval stage in the water before beginning their
life on land.                                                                   Class Mammalia
          Adult amphibians are carnivores. They have a three chambered                   Mammals have several characteristics not found in other
heart and are ectothermic. They have a brain which is the central part of       vertebrates. They nurse their young using milk from mammary glands.

                                                                                                                 Lakeside High School Science Department
Mammals have live births - the young are born live after spending time in     The coelom is divided into two smaller cavities by the diaphragm. The
their parents developing.                                                     thoracic cavity lies above the diaphragm and contains the heart, lungs, and
          They have body hair that acts as insulation and also protects the   esophagus. The abdominal cavity lies below the diaphragm and contains
body from injury. Mammals have a large well-developed brain and they are      the organs of digestion, reproduction, and excretion. The cranial cavity is
the only animals that have an external outer ear for hearing. Their body is   inside the skull and contains the brain.
divided into two parts - the chest and the abdomen. The diaphragm                      There are four tissues associated with the body. Epithelial tissue
separates the two parts.                                                      has one or more layers and it protects all internal and external body
          They are endothermic. They have a four-chambered heart and an       surfaces. It makes up our skin, the lining of blood vessels and intestines,
efficient, closed circulatory system. Mammals have a well-developed           and the protective covering of the heart and lungs. Connective tissue is the
cerebral cortex and have a complex nervous system.                            most widely distributed tissue in the body. It joins, supports, and protects
          Mammals include monotremes (duck-billed platypus, spiny             other types of tissue. It includes bones, blood, fat, and the tissue
anteater). They have mammary glands, which make them mammals, but             surrounding nerves. Muscle tissue is specialized cells with the ability to
they lay eggs. Mammals also include marsupials (kangaroos, koalas,            contract and produce movement. Nervous tissue is composed of cells that
opossums). They bear live young, but the young are not as developed as        can transmit messages throughout the body.
other mammals. These babies complete their development inside a pouch
attached to the mother.
          Placental mammals include 95% of all mammals. The embryo of a                         SYSTEMS OF THE HUMAN BODY
placental mammal is implanted in the mother’s uterus - the mother’s
reproductive organ. The placenta forms, connecting the young mammal           Digestive System:
directly to the mother.                                                                 The digestive system is responsible for both mechanical and
                                                                              chemical digestion that break down food into molecules so that they can
                                                                              move into the cell and be used for the living process. The mouth, teeth, and
                           HUMAN BODY                                         tongue begin the chemical digestion by mechanically breaking down food
                                                                              through the chewing process and the addition of saliva. The enzyme
          Humans are members of the kingdom Animalia, phylum Chordata,        amylase breaks down carbohydrates and starts the break down of starches.
class Mammalia, and order Primates. The traits that make us humans are        Food moves from the mouth to the stomach by way of the esophagus. In
refinement of traits found in other primates. Primates include monkey,        the stomach, other digestive enzymes and hydrochloric acid begin the
apes, and orangutans. Several primate characteristics include a complex       breakdown of proteins. The stomach mixes and churns the food.
and well-developed brain, sophisticated eyes that can distinguish small                 Food, now in a liquid-like state called chyme, moves from the
details, opposable thumbs (a thumb positioned opposite the other fingers),    stomach into the small intestine, where it is absorbed through the villi (walls
long arms with flexible shoulders and write joints, and four types of teeth   of the intestine) into the bloodstream where it is delivered and taken in by
(incisors, canines, premolars, and molars).                                   the cells of the body. The majority of chemical digestion and absorption
          Humans are distinguished from other primates by having a brain      takes place in the small intestine. Waste materials and unused food are
larger than any other primate. We can stand upright and walk under all        carried back to the large intestine where they mix with roughage and water.
conditions. Our jaws and teeth are different. Our teeth are smaller than      The undigested materials are excreted from the body.
primates and allow us to hold food as well as tear it. We have the capacity
for language - both spoken and written.                                       Circulatory System
          The human body is divided into four main parts - head, neck,                 The circulatory system is composed of the heart, arteries, veins,
trunk, and limbs. The body is built around a jointed, bony skeleton covered   red blood cells, white blood cells, antibodies, thrombin, water, and plasma.
with layers of muscle and skin. Inside the trunk of the body is the coelom.   A four chambered heart, controlled by a pacemaker, rhythmically controls

                                                                                                              Lakeside High School Science Department
the pumping action by alternating contractions of the atria and ventricles.             The basic unit of the nervous system is the neuron (nerve cell). Its
Blood circulates in the body in two loops - arteries carrying oxygenated       structure allows electrochemical signals to travel across synapses to activate
blood from the heart to all parts of the body, and veins returning             muscles, glands, or organ tissue. The nervous system is divided into two
deoxygenated blood to the heart and lungs to be reoxygenated. Blood flows      parts. The first part is the central nervous system, which includes the brain
through the arteries due to the pumping pressure of the heart. In the veins,   and the spinal cord. The second part is the peripheral nervous system,
blood flow back to the heart (against gravity) is helped by skeletal muscles   which is a large network of nerves that totally connect all parts of the body.
that squeeze the veins and push blood along and by one-way valves located      Receptors located in sense organs (eyes, ears, etc.) and in the skin send
in the veins themselves.                                                       information along sensory neurons to the spinal cord and then to the brain
          An auxiliary portion is the lymphatic system, which drains excess    where the information is chemically interpreted, causing a motor response.
tissue fluids back into the circulatory system along with white blood cells
that destroy harmful organisms.
                                                                               Respiratory System
Skeletal System                                                                          Respiration involves actions started by nerves stimulating muscles
          The skeleton is the basic framework of the human body and is         and bones to mechanically enlarge the respiratory cavity of the body. The
made of connective tissue - bones and cartilage. Bone is living tissue with    diaphragm contracts and moved downward. The breathing rate is controlled
vitamins, collagen, and minerals to give it strength and hardness. The         by nerves originating in the brain based on carbon dioxide content. The
process by which the bones harden is called ossification. Bones are joined     human nasal passages are adapted to clean, moisten, and warm the air
by cartilage at joints. Joints are classified as to the amount of movements    before it enters the lungs by way of the trachea and the bronchi. The lungs
they allow: stationary (skull), hinge (jaw), and ball and socket (hip).        are made up of many tiny air sacs called alveoli that are found at the end of
                                                                               the bronchiole in clusters. The exchange of gases between the lungs and the
Muscular System                                                                blood vessels occurs in the alveoli.
         Three human muscle types are skeletal, smooth, and cardiac. All
muscle tissue exerts force when it contracts; therefore muscles are
responsible for all movement of the body, voluntary and involuntary.           Excretory System
Energy for all movement is derived from an ample supply of mitochondria                 The excretory system is made up of the kidney, bladder,
in the muscle cell. ATP, a high level energy carrier, is produced by the       connecting tubes, and capillaries joined to the kidney. Urine is collected by
mitochondria for use by other cells and tissue parts during movement of        structures in the kidney called nephrons. From the nephrons, the liquid
exercise. Muscles are paired to accomplish full movement. Each                 wastes are collected and stored in the bladder. Urine leaves the body
contracting muscle will be paired with an muscle that works against it and     through the urethra.
tendons attach paired muscle groups to bones to complete the movement
action. The skeletal muscles make up this grouping of muscles and are
mainly voluntary. Smooth muscles are found in the linings of the body          Endocrine System
such as the digestive tract and blood vessels. They are generally                        The endocrine system produces hormones which travel by way of
involuntary muscles.                                                           the bloodstream to specific target cells. Endocrine glands include the
         Cardiac muscle is found only in the heart. The heart is the           thyroid, adrenals, pancreas, parathyroid, gonads, pituitary, and the
strongest muscle of the body. It is responsible for keeping the blood          hypothalamus. The manner in which the hormone acts on the target cells
flowing through the circulatory system at a given pressure. The cardiac        depends on whether it is a protein or steroid. Each will cause a feedback,
muscle is an involuntary muscle.                                               which is one way to regulate hormones secreted into the body. Homeostasis
                                                                               depends on the actions of the nervous and endocrine systems. Organs, like
Nervous System                                                                 the kidney, function based on endocrine stimulation.

                                                                                                               Lakeside High School Science Department
Integumentary System                                                                       Ecosystems must maintain an ecological balance. This can be
         The integumentary covering of the body is called the skin. Skin          helpful or harmful to the members that make up the community depending
consists of two layers, the epidermis, and the dermis. Skin protects the          upon whether they are predators or prey. A predator is an animal that feeds
body, rids the body of mineral salts and wastes, regulates body temperature,      on other living things. The animal it feeds upon is the prey. Lions
and picks up environmental signals. The skin is the bonding or holding            (predator) hunt down and kill antelope (prey).
agent that keeps the body intact and functioning. Also part of the                         Each of the biotic organisms in an ecosystem interrelate with the
integumentary system is the nails and hair.                                       others. A symbiotic relationship between two members of a community is
                                                                                  one in which one or both parties benefit. Commensalism is a relationship
Reproduction System                                                               in which one member is the host, but causes no harm to the other organism
          The reproductive organs in males and females are called gonads.         (barnacles on whales). Mutualism is a relationship in which two living
Gonads produce sex cells called gametes. Gametes are haploid - they have          organisms live together in dependency on each other (the protozoa in the
half the normal amount of chromosomes. When an egg and sperm unite,               human intestine). Parasitism is a relationship that involves a host organism
the resulting fertilized egg, or zygote, has a full set of 46 chromosomes. In     which is harmed by the presence of the other organism (fleas on dogs and
the male, the gonads produce sperm and male hormones. In the female, the          cats).
gonads produce the egg cells. Reproduction starts with the union of a
sperm and an egg. Fertilization occurs in the fallopian tube (the oviduct in      COMMUNITIES
human females). The combined cell, called a fertilized egg cell, develops                   An ecosystem’s biotic factors interact with each other and
quickly into a ball of many cells that implants itself on the inner wall of the   compose a community of living things that coexist. Each community is
female uterus. Here it develops into a fetus, the name given to the               composed of populations. A population is a group of small individuals of a
beginning stage of a human being. For nine months the fetus grows, it             single species that occupy a common area and share common resources.
receives nourishment from the mother’s circulatory system.                        The number of populations within a community varies. A tropical rain
                                                                                  forest community may have thousands of populations while a desert
                                                                                  community may have very few.
                                                                                            Just like communities are made up of populations, each
                                                                                  populations is composed of interacting individuals. Each individual
                                ECOLOGY                                           organism lives in a specific environment and pursues a particular way of
                                                                                  life. The surroundings in which a particular species can be found is called
ECOSYSTEMS                                                                        its habitat. An organism can inhabit an entire ecosystem like a woodpecker
          Life on earth extends from the ocean depths to a few kilometers         might occupy the whole oak forest. But the spider may only inhabit the
above the earth’s surface. The area where life exists is called the biosphere.    trunk of one of the oak trees.
The biosphere can be more easily understood by breaking it into smaller                     The way of life that a species pursues within its habitat is called its
components called ecosystems.                                                     ecological niche. An organism’s niche is composed of biotic and abiotic
          An ecosystem is a physically distinct, self-supporting unit of          factors. Some niches can be very broad (rats) while others can be very
interacting organisms and their surrounding environment. It is made up of         limited (panda).
biotic and abiotic interactions. The biotic factors of an ecosystem are the
living organisms in the area. The abiotic factors are the non-living, or          THE FLOW OF MATERIALS
physical, components of the area like light, soil, water, temperature, wind,               Each ecosystem has its producers, consumers, and decomposers.
and nutrients. The essential factors that make an ecosystem successful are a      They make up a cycle called a food chain. Food passes from one organism
source of energy, a storage of water, and the ability to recycle water,           to another in the food chain. Energy is used up by each consumer in the
oxygen, carbon, and nitrogen.                                                     food chain. Plants make food, animals eat plants, some animals eat other

                                                                                                                   Lakeside High School Science Department
animals, and some animals eat plants and other animals. Herbivores are
animals that eat only plants. Carnivores are animals that each only other       BIOMES
animals. Omnivores are animals that eat both plants and animals. A                        Communities are members of a larger ecological unit called a
Saprophyte is an organisms that feeds on dead organisms.                        biome. A biome is an extensive area of similar climate and vegetation. A
         There are many food chains in an ecosystem. The least amount of        biome’s abiotic (non-living) factors determine what plants and animals live
energy consumed is the item highest in the food chain. In the preceding         there. The major influences are temperature, light intensity, and patterns of
example that would be the human. All the food chains in an ecosystem            rainfall, which determine the availability of water. There are six basic
make up the food web of the area. Most food chains overlap because many         biomes on earth: tundra, taiga, grassland, deciduous forest, desert, tropical
organism can eat more than one type of food.                                    rain forest.
         All organisms need certain chemicals in order to live. The most                  Biomes that are closest to the poles experience the coldest weather
important ones are water, oxygen, carbon, and nitrogen. The continuous          conditions for they are furthest away from the sun due to the tilting of the
movement of chemicals throughout an ecosystem is called recycling.              earth.

         An ecosystem goes through a series of changes known as
ecological succession. Succession occurs when one community slowly
replaces another as the environment changes. As succession in a
community continues, it finally reaches a climax community. A few
organisms establish themselves and become the dominant species in the
area. The complete process of succession may take anywhere from a
hundred to thousands of years, depending upon the communities.

          The population of an area is affected by the new offspring
produced in the area. New plants and animals moving in from other places
increase the size of the population. The death of organisms and animals
moving out of the area decrease the size of the population. There is a direct
relationship between the number of plants and animals in an area which is
in ecological balance. If the number of one of them is increased or
decreased, it will affect the numbers of the other. During deer season, the
number of deer is reduced by man. The plants that the deer eats will
increase during this season.
          A change in populations may be helpful or harmful to the
community. If insects are killed by insecticide, the animals that depend on
they for food must move elsewhere. Even the human population changes as
he seasons change. In the summertime, the coastal area is more widely
populated by vacationing people. In the wintertime, the snowy,
mountainous areas are more populated by snow skiers.

                                                                                                                Lakeside High School Science Department
          Natural resources are necessary for human survival and the making
of necessary products. The natural resources are water, air, soil, wildlife,
and forests. Problems that are now being faced are related to erosion, soil
depletion, species extinction, deforestation, desertification, and water
shortages. Efforts to reverse these problems and their environmental
damages are found in the planned programs of reforestation, captive
breeding, and planned farming through efficient plowing and planting
          Disruptive changes can easily upset the stability of an ecosystem.
Destructive acts of nature can occur. A forest fire can destroy all plant and
animal life in a forest, along a river, and around the shore of a pond. It can
also pollute a pond with ash.
          Humans are unique in our ability to modify our ecosystem.
Pollution from human acts can also affect an ecosystem. A chemical spill
or pesticides sprayed overhead can kill all plant and animal life with which
it comes in contact with. A housing development along the bank of a river
or on the shore of a pond can bring both garbage and noise pollution, in
addition to direct physical destruction of these habitats.
          Pollution is damaging to both the ecosystems and living organisms.
Air, soil, and food resources are being affected by pollution. Pollutants
include automobile exhaust, fertilizers, pesticides, industrial wastes,
radioactive wastes, and household wastes. Pesticides like DDT become
absorbed by the animal and concentrated in their bodies. Acid rain forms
from the exhausts of automobiles which emit sulfur and nitrogen oxides.
These combine with water in the air to form sulfuric and nitric acids.
          The growing population and modern conveniences greatly
contribute to the problems of pollution. Government regulations,
community efforts, and changes in habits of industries and individuals are
necessary to solve pollution problems.

                                                                                 Lakeside High School Science Department

To top