Transcript I. Reproductive Systems

BIOLOGY NOTES
GENETICS PART 3
PAGES 151-155, 786-805
Standard:
____
4.16 Describe the basic anatomy and
physiology of the human reproductive system.
Describe the process of human development
from fertilization to birth and major changes that
occur in each trimester of pregnancy.
Essential Questions:
1. How does the fetus develop from
fertilization to birth?
I. Reproductive Systems
In order for a species to continue, reproduction of
new individuals must occur. Each individual
cell and continues to grow
begins as a single ____
mitosis until enough
through the process of _______
cells have been created to sustain life in the
outside world.
• Reproductive System = a collection of
organs glands and _______
tissues that
specialized _______,
individual being
help to produce a new _________
• In humans, reproductive organs are not fully
puberty
functional until ________
growth and
 puberty = a period of rapid _______
sexual maturation during which the reproductive
functional
system becomes fully __________
A. The Male Reproductive System
• The main function of the male reproductive
sperm
system is to produce and deliver _______
 The testes are the male reproductive organ
sperm
responsible for the production of _______
scrotum outside of the
and stored in the ________
body
FSH and ____
LH stimulate
 the hormones _____
sperm
the testes to produce ______
 The testes are outside of body because it is
3° cooler which sperm require for
about ___
formation
proper __________
tubules inside the testes
 Seminiferous ________
actually make the sperm
 For sperm to exit the organism, it must move
vas
into the ___________,
epididymis through the ____
penis
deferens and out of the ______
 There are approximately _____
2.5 million sperm
per drop in semen
B. The Female Reproductive System
• The main function of the female reproductive
ova (egg) AND provide a
system is to produce ____
embryo
nourishing environment for an ________
sperm
• Unlike males who produce _______
continuously throughout their lifetime, females
only produce one mature ____
ova or egg each
month (about every ___
28 days)
_______
 Eggs are stored in the ______
ovary or the female
reproductive organ
• Each egg has clusters of ________
follicles attached to
mature before
it which help the egg become _______
leaving the ______
ovary
• ovulation = the release of a mature egg from
the ______
ovary
• For eggs to exit the ovary, it must move into the
uterus cavity
_________
fallopian tube and into the______
• if the egg is _________
fertilized then it will implant in
uterus and an embryo will form
the _______
• if the egg is NOT ________
fertilized then it will exit the
uterus through the ______
cervix and out of the
_______
vagina
fallopian
tube
uterus
5 to 7 days to uterus
follicle
ovary
egg cell
egg released
uterine wall
corpus luteum
 Remember, the function of the female
reproductive system is NOT just to make eggs
environment
but to also provide a nourishing ____________
uterus
which comes from the _______
 every time an egg is released, the uterus
embryo
prepares for an implanted ________
 if the egg is not fertilized, then the lining of
the uterus will ______
shed and exit with the
cervix and out
unfertilized egg through the _______
of the vagina
• Menstruation = the phase of the menstrual
______
cycle in which unfertilized _____
eggs and the
uterus actually _____
lining of the ________
exits the
female body
C. Stages of Pregnancy
fertilized by sperm in
• Eggs usually become _________
fallopian tubes
the _________
egg
• Zygote = a fertilized _____
• as soon as the zygote is formed, it undergoes
_________
mitosis which increases the number of cells
4 days after the formation of the zygote,
• about __
the embryo is approximately ___
64 cells large and
morula
called a ________
blastocyst is what implants or embeds
• the ___________
uterus
itself in the wall of the _______
• from here the embryo will continue to grow in
differentiate or
size and the cells will ____________
_____
become specialized until the fetus is born (this
9 months in humans)
takes approximately __
1. FIRST TRIMESTER (WEEKS 1-13)
 neurulation = the beginning development of
the _________
nervous system
 the placenta forms
placenta = the connection between a
mother and a developing ________
embryo through
_______
wastes are passed
which nutrients and _______
diffusion
(through the process of _________!!!!)
 eye formation, jaws, arms, legs, fingers, hands,
toes become __________
noticeable
 fetus = name of embryo at week __
8 of
pregnancy
forms from placenta to
 umbilical cord ______
mother
________
11 the baby has all the major
 by week ___,
organ systems partially developed
______
 fetal heartbeat develops
2. SECOND TRIMESTER (WEEKS 14-27)
skeleton
 bone formation begins and early _________
develops
fetus
 hair covers the ______
movement that can be felt
 the fetus begins ___________
mother
by the ________
developed and there is
 hearing is well __________
eye movement
evident rapid ____
3. THIRD TRIMESTER (WEEKS 28-40)
mature and the fetus
 organ systems _______
doubles in mass
________
temperature is now
regulation of body ___________
possible
the central nervous system and lungs complete
their development
the fetus moves into head down into the
______
pelvis and awaits birth
II. Cell Differentiation = the process by which
forms
unspecialized cells develop into mature ______
functions
and __________
• The function of a cell will be determined by its
location within an embryo
________
 once a cell’s function is determined, the cell
DNA needed to
will only use parts of the _____
help with that particular function
• Stem cells = a cell that can divide for long
periods of time while remaining
_______________
undifferentiated
 stem cells are classified according to which
type of cell they can become:
_____
a. totipotent stem cell = a type of stem cell
any type of cell
which can become ____
e.g. fertilized egg
b. pluripotent stem cell = a type of stem cell
which can become ____
any type of cell EXCEPT a
totipotent stem cell
e.g. embryonic stem cell
c. multipotent stem cell = a type of stem cell
closely related cells
that can only grow into _______
e.g. adult stem cell
First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an
inner cell mass. These cells are then removed and grown with nutrients. Scientists try
to control how the cells specialize by adding or removing certain molecules.