Biology is the study of life by B3JK6W

VIEWS: 4 PAGES: 6

									Biology is the study of life.
               Any living thing is called an organism.
Characteristics of life
 Living things have organization. -They have special parts for special functions.
        .       Organisms reproduce.
                    ---Reproduction assures that a species will continue into the future..
                    -----Species can interbreed and produce fertile offspring.
                All organisms grow and develop.
                       --Growth increases the amount of living material and forms new structures
                       --Development are the changes that take place during growth.
               Organisms respond to stimulus in the environment and adapt.
                       --Environment includes all the surroundings - air, water, soil, other organisms and etc.
                       --A stimulus is a condition that requires organism to adjust.
                       --A reaction to a stimulus is a response.
                       --An adaptation is any structure, behavior, or process that enables and organism to
                         respond stimuli and enables the organism to survive.
Organisms try to maintain homeostasis. Homeostasis -living things ability to maintain conditions suitable for
life. Needs energy to happen.
        .
     Nature of science -- continuous process of discovery. As new facts are discovered old ideas might be
     changed.

Scientific Method
1.Scientific method - steps used by scientist to solve problems.

       1. Identify a problem or question. Research and learn something about the subject about which
          you have a question
       2. Hypothesis - a testable explanation for a question or problem
       3. Experiment - procedure to test hypothesis under controlled conditions.
             ---Control - the standard in which all conditions remain the same.
             ---Independent variable - conditions in an experiment that is changed.
             ---Dependent variable - the condition that might result from changes of the
                 independent variable.
       4. Make observations and take data.
            ----data - observations and measurements and other info collected during     experimentation.
             ---- data based on numerical measurement or counting is quantitative.
             ---- data based on observations such color, actions, or things not measured
                  numerically is called qualitative data.
       4. Analyze Data and make a Conclusion - analyzing data to see if it supports the hypothesis.

Many times experiments are reported in scientific journals for scientists to consider and use in other
experiments.

To verify an experiment, it must be repeated to see if results are the same.

If an observation or experiment supports a hypothesis after being repeated many times, it is often called a
theory.

A theory is an explanation of a natural phenomenon that is supported by large body of evidence.

New evidence or experimentation and observation might change theory.

Often a theory because so established, they are call laws. Examples include the law of graivty, the law of
conservation of energy.
               Organisms and their environment
Natural history -observant of plants and animals in nature.
Ecology is the scientific study of interactions between organisms and their environment.
Biosphere is the portion of Earth that supports life.
Biotic factors include all living organisms that inhabit an environment.
Abiotic factors include the non living parts of the environment - air current, temperature, moisture, light, soil.

               LEVELS OF ORGANIZATION
Organism - each individual living things.
Population - groups of organisms of one species living in the same place at the same time.
Community - a collection of interacting populations.
Ecosystem - made of interacting populations in a community and the community's physical surroundings.
A niche is the role a species plays in a community. ex. coyote keeps down rodent population in a grassland.
A habitat is the place where an organism lives.
Autotrophs use sun's energy or energy in other chemical compounds to make their food energy. ex. plants.
Heterotrophs depend on autotrophs for their food -- ex. most animals.

Types of heterotrophs
       herbivores - animals that consume only plants.
       carnivores - animals that consume only other animals.
       scavengers - feed on dead animals or dead organisms.
       omnivores - eat both plant & animals- breakdown organic compounds in dead or decaying
                     organisms.
       decomposers- break down dead organism into simpler substances that can be reused by other
organisms.

MATTER & ENERGY IN ECOSYSTEMS.
     Food chain is a model of energy's movement through ecosystem.
     Trophic level - 1 step of the passage of energy through food chain.
     Food web - a model expressing all food relationships in a community.
     Ecological pyramid - model depicts energy conversion in an ecosystem.
     As energy moves through an ecosystem, the amount decrease and only about 10 percent moves to
           the next higher level.
Biomes
A biome is a large group of ecosystems.
Marine biomes are in the water. Found in the sea, lakes, rivers, streams and etc.
Terrestrial biomes are on land.
Ice - few animals, few plants - always cold and soil poor and frozen
Tundra – few animals and plants - short growing season – ground always frozen- called permafrost-
Taiga – conifer type trees, somewhat warmer and wetter than tundra, long winters, short summer and growing
        season, poor top soil, animals are more abundant .
Temperate Forest – mostly broad leaf trees that loose their leaves in fall (deciduous)- rich topsoil but not
        deep only a thin layer, many common animals,
Tropical Rainforest - lush plants because of much rain, dense jungles, roots shallow - most nutrients are in
        the plants and animals – not much humus ( rotted organic material) because
        It would be decomposed quickly and used by plants to grow more plant material. Many different kinds
        of plants, animals, especially reptiles, amphibians and birds.
Grassland - many small plants like the grasses – usually has a wet and dry period, has a large number and
        variety of plants and animals- some are grazers like the buffalo. – lots of variation of plants and animals
        – soil has much humus from rotting plants
Desert.- Very little animal and plant life. Most animals here are herbivores and most plants small and adapted
        to live in a dry climate– little rainfall and can be hot during the day. – poor soil
        Very little or no annual precipitation.
               Chemistry of LIfe
Element - substance that can't be broken down into simpler substances.
# 90 occur in nature. -- 25 are essential to living things
# 4 elements, Carbon, Hydrogen, Oxygen, and Nitrogen make up about 96% of human mass.
# each is represented by a a one or 2 letter symbol . The first letter is always captilized and the second is in
       lower case. ex. C = carbon Ca = calcium              Cl = chlorine

# Some elements like iron (Fe) and magnesium (Mg) are needed by human body in only small or trace
       amounts.
# The smallest particle that can have and stilll have that element's characteristics is an atom.

 STRUCTURE OF AN ATOM.
# The central core is the nucleus   (nuclei is plural)
# Nucleus contains positively charged protons (p+) and neutrally charged neutrons (no)

Isotopes
# Atoms of the same element that contain equal numbers of protons and electrons but have a different number
      of neutrons are called isotopes.

Compounds
# A compound is a substance composed of 2 or more elements chemically combined in certain amounts/
ex. H20 or water is composed or 2 parts hydrogen and 1 part oxygen.
 # Various combinations take place because the outer energy level is usually stable when it has 8 electrons.

Covalent Bonds and compounds.
# To stabilize it outer energy level some elements share electrons. This sharing of electrons is called a
 covalent bond.
 # These covalent compounds are called molecules. ex. sugar, fats, proteins, water.
 # Most compounds in organism have covalent bonds.

Ionic bonds and compounds
# Sometimes the atom can stabilize its outer energy level is by gaining or losing electrons to another atom.
# The atom that gains or loses the electron has a + or - charge and is called and ion.
 # Since opposite charges attract compounds are Formed when oppositely charged ions share electrons. This
    is an ionic bond.
 # Ionic bonds are not nearly so numerous but are important in biological processes.

Mixtures
Sometimes elements are mixed together but no chemical change happens. The amounts of the parts that
      make up a mixcture can vary from mixture to mixture. Ex, You can put more or less sugar in a mixute
      of water and flavoring to make Kool aid depending on your taste but both would still be a mixture.

# Solution - mixture where one or more substance are distributed evenly in another.Ex. kool-aid sugar water.

# Solvent - substance you dissolve into ---# Solute - substance you put into the solvent.
 # The greater the amount of solvent in the solute, the greater the concentration.
# Concentrations of solute in solvent is important to an organisms homeostasis.
       ex. too much sugar in blood = diabetes.

               Water’s importance as a polar compound.
# Water is the most important compound in a living organisms.
 # Water is a covalent compound and has an unequal distribution o# change - it has a - and + charge. This
       uneven charge makes it a polar compound.

Chemical Reactions
****Metabolism- all the chemical reactions that occur in an organism.
 # Chemical reaction are represented by chemical equations using formulas.
# During a chemical reaction all the atoms in the reactants will be found in the products.


Acids and bases
# pH measures how acid or basic something is on a scale o# 0-14.
 # 14 is the most basic, 0 the most acidic, and 7 is neutral.
 # Acids form H+ ions and bases form hydroxide ions (OH-) ions when in water solutions.
 # Proper pH is important to organisms.

 Carbon, isomers and polymers
 # Carbon has 4 electrons in its outer energy level available ffor covalent bonds.
 # This property makes a large number of carbon compounds possible.
 # Isomers - compounds that have the same chemical formula but different structures.
ex. fructose and glucose.
 # A polymer is a large molecule formed when small molecules bond together.

Carbohydrates
# Carbohydrates - organic compound composed of C, H, and O with a ratio of 2 hydrogen to 1 oxygen
Surgar is a carbohydrate- some form larger polymers like these:
        # A Monosaccharide - a simple sugar carbohydrate ex. glucose & Fructose.
        # Disaccharide - 2 simple sugars combined. ex. sucrose.formed by a condensation reaction of
                fructose and glucose.
        # Polysaccharide - composed of many saccharides. ex.starch, cellulose, and glycogen.
 # Starch is a carbohydrate made of many glucose units and is used by plants to store food.
 # Glycogen is a polysaccharide polymer of glucose units and is used by animals to store food.
 # Cellulose is a polymer of glucose which form plant cell walls.

Lipids (also known as fat)
# Lipids have a large proportion of carbons and hydrogen bonds and less oxygen than sugars.
 # Lipids are insoluble in water because they are non polar.
 # Cells use lipids to story energy, insulate, and form a protective coating. ex. are fats, oils and waxes.

Proteins
# Proteins are large complex polymers of carbon, hydrogen, oxygen, and nitrogen and sometimes sulfur.
       Proteins are essential to life.
 # Amino acids - 20 common ones that are the building block of proteins. Vary in size and shape.

# Amino acids link together by condensation. (the removal of aH+ ion or and OH- ion ) between amino acids.
 # Peptides bonds are the covalent bonds formed between amino acids to form proteins.
 # The order of the amino acids determines the protein.

Enzymes
# Enzymes are special proteins that speed up or slow chemical reactions in our bodies.
 # Because enzymes can speed up a reaction, the reaction take place at reasonable temperature under
  conditions present in living cells.

Nucleic Acids
Are nucleic acids are complex macromolecules that stores info in a genetic code and made of nucleotides.
# DNA is the master genetic code.
# RNA coded in a cells nucleus by DNA to tell the cell how to put amino acids together for protein synthesis

Discovery of Cells.


                                                                                      .
  Compound microscopes have 2 or more magnifying lens and allow us to study small objects.
Cell theory.
                                                             summarized into the cell theory.
      1. All organisms are made of 1 or more cells.
      2. Cell is basic unit of organization of organisms
      3. All cells come from preexisting cells.
2 TYPES OF CELLS.

       lack internal structures that are surrounded by membranes.
       have no true nucleus
       most are 1 celled organisms.


      contain internal membrane bound structures called organelles.
      nucleus is the largest organelle andcontains the DNA that manages the cell's functions.
      can be 1 celled or many celled.


       becomes specialized and allows several chemical reactions to be carried out at the same time.


ORGANELLES & OTHER CELL PARTS
#Nucleus Control all that goes on in a cell and is porous so material can enter and leave nucleus.
      With in the nucleus is DNA in long strands of chromatin which packs into chromosomes when
      time to reproduce cell.

# Nucleous is in nucleus is involved in protein synthesis.

#Ribosomes are sites in cells where enzymes and other proteins are assembled.


#Cytoplasm is the fluid like material in a cell and surrounds the organelles outside the nucleus.
      It is a clear fluid that is jelly like.
      It makes up a little more than 1/2 the cell's volume.

#Endoplasmic recticulum delivers materials to ribosomes for assembly as protein.
  Rough ER has ribosomes attached
  Smooth ER is without ribosomes.
  Ribosomes assemble proteins.
  Some lipids are made on ER.

#Golgi apparatus are a series of closely stacked flattened membrane sacs that are receive from ER the
proteins and lips for distribution to plasma membrane.

#Vacuoles are sacs of fluid surrounded by a membrane.
1. Used for storage food, enzymes, and other cell products or wastes.
2. In some 1 celled organism they collect excess water and pump it out of cells.
3. In plants, large vacuoles store water and food.

#Lysomes contain digestive enzymes that digest worn out cell parts and other cell parts.

#Mitochondria is where food molecules are broken down to release energy.
  Like many other organelles are folded in their interior to give greater surface area.

#Cholorplasts are found in green plants and some protists.
1.   can transform light energy into chemical energy.hey have chlorophyll, a green pigment, that traps light
2.   energy and makes plants green.
3.   Chloroplasts are an organelle types called plastids.
4.   Some store starches and lipids.
5.   Some have pigments for color and are named after their color.

# Cytoskeleton is composed of tiny rods and filaments to form cells framework.
1. Made of mostly microtubles and microfilaments.
2. Microtubles are thin hollow walled proteins tubes.
3. Microfilaments are thin solid proteins fibers.

#Some cells have cilia and flagella which are structures used for motion or movement of fluids over cell.
1. Cilia are short hairlike and usually in large numbers.
2. Flagella are longer an whiplike and usually only 1 or two to cell.

#Plant and animal cells have similar structures and functions but each kind of cell is adapted to the
organism that it composes.

Plant cells have large vacuoles and cell wall which helps distinguish them from animal cells,

CELL ORGANIZATION.
               - one celled. 1 cell performs all function of life.

multicellular - made of many cells.
   different cells may perform a special function of life.
   ex. for reproduction, movement, or digestion.

A group of cells function together are tissues. ex. nerve, muscle, bone, stems, roots.

2 or more tissues acting together arecalled an organ. ex. leaf, stomach,. brain

A group of organs that operate together are called an organ system. ex. flower, nervous system, digestive
system

Cell Membrane
The movement of particles from an area of high concentration to one of lower concentration is diffusion

The internal pressure of a plant cell is called turgor pressure.

The plasma membrane surrounding the cell only allow only some materials to pass through it. This is called.
selective permeability.

The diffusion of water molecules through a selectively permeable membrane is called passive transport.

A plasma membrane is made up of a lipid bilayer.

The plasma membrane is made of 2 layers.

								
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