Sex Notes
Biology/ Hopson
Definition of Sex
• The property or quality by which organisms are classified as
female or male on the basis of their reproductive organs and
functions.
• Either of the two divisions, designated female and male, of this
classification.
• Females or males considered as a group.
• The condition or character of being female or male; the
physiological, functional, and psychological differences that
distinguish the female and the male. See Usage Note at gender.
• The sexual urge or instinct as it manifests itself in behavior.
• Sexual intercourse.
• The genitals.
» Stedman’s Dictionary
Two Main Schemes Organisms
Use To insure That Genetic
Information Is Passed To The
Next Generation:
Asexual Reproduction
Sexual Reproduction
Terms
Gamete (n)
Mature male or female
reproductive cell (sperm or
ovum) with a ½ the
chromosomes need to make a
complete organism (23 for
humans).
Zygote 2n
A zygote is the product of the
fusion of an egg and a sperm
(embryo). It contains a
complete copy of the
chromosome -- one from each
parent.
Asexual Reproduction
A type of reproduction
involving only one parent
that produces genetically
identical offspring by
budding or division of a
single cell or the entire
organism into two or
more parts. (Bacteria,
single celled organisms,
and some plants)
Sexual Reproduction
A type of reproduction
in which two parents
give rise to offspring
that have unique
combinations of
genetic material that
is different from the
parents and other
offspring (Animals,
plants, fungi, protists
and bacteria!
Hermaphrodite
• An individual that Earthworms
functions as both
male and female in
sexual reproduction
by producing both
sperm and egg. (i.e.
plants, animals).
Snails (not crabs!)
• Flowers contain the sexual organs of
plants, most plants have organs to
produce both the male and the female
gametes inside the flower, whereas most
animals produce only male or only female
gametes.
Special Note
Dean Ballard once said
“Biology is a mess!” This
is true! Many bacteria can
engage in sex and some
animals are
hermaphroditic! As a
matter o’ fact, when it
comes to the way life
adapts to the
environment in which it
occupies, there is most
likely an exception to
every rule.
Angiosperms
Today we will focus our
attention on the Kingdom
called. There are two different
kinds of plants, gymnosperms
and angiosperms.
Gymnosperms (naked seeded
plants with pinecones) are
interesting, but today we will
learn about Angiosperms.
The term Angiosperm is
derived from two Greek words:
“," (or vessel) and "sperma" (or
seed). In all angiosperms, the
seeds are enclosed in a
leaflike structure where the
female sex parts exist.
The structure of the flower, along with other
adaptations, has been very successful; in fact, most
terrestrial plants are of the flowering variety.
All angiosperms
reproduce with
what we humans
lovingly call
“flowers”.
Flowering plants are great
because. . . .
• They do not need water
for the gametes to be
fertilized
• They often have both
male and female parts
• Their petals can attract
pollinators (Think of a
pretty flower as a
McDonalds sign,
advertising food (nectar)
for pollinators like The
Birds and Bees.
Today you will observe and sketch the
main reproductive parts of a flowering
plant. You should walk away from class
knowing what each part does and what it
looks like.
Male
Stamen (which includes)
Anther
Filament
Female
Pistil (Which includes)
Style
Ovary
Stigma
Other Relevant Parts
Petal
Stem
.:.