module 9 Flashcards
the method by which organisms make offspring
reproduction
Two basic methods of reproduction
- Asexual reproduction
- Sexual reproduction
Genetic sex determination consists of what chromosome configuration?
XX or an XY sex chromosome configuration
Genes from two individuals are combined in new ways to generate variety in offspring.
Sexual reproduction
XX genetic configuration
female anatomy
Why is variety in offspring desirable?
increases the odds of offspring surviving
XY genetic configuration
male anatomy
(T/F) germ cells or gametes (eggs and sperm) each have half the genetic information that a regular cell of that species of organism has
TRUE
True or False:
all embryos are inherently female and female is the default condition
True
In sexual reproduction, what process do germ cells or gametes (eggs and sperm) use to produce a new cell that has the full complement of genetic material for that species of organism.
Fertilization
how does one become male or female?
determined by the hormones that an embryo is exposed to early in development.
True or false
your genes determine whether you make ovaries or testes and then the hormones made by those organs determine the internal and external reproductive anatomy.
True
All embryos have structures that can either become the _______ or the testes.
ovaries
sexual reproduction introduces a lot of variety into these new cells because of what 3 processes?
- crossing over during meiosis
- independent assortment
- random fertilization
At about ___ weeks of development, if the embryo has a Y chromosome, the SRY (sex determining region of the Y chromosome) gene causes these structures to become _____.
- 6 weeks
- testes
How many chromosomes do humans have?
46 (23 pairs)
Testes form _____ cells that start to secrete _______ such as testosterone and _____ cells that start to secrete MIF/MIS (Mullerian inhibiting factor/substance).
- Leydig
- androgens
3.sertoli
Does the mom or dad determine a person’s genetic sex?
the dad
When eggs and sperm fuse during fertilization, the only thing that the sperm adds is what?
50% of nuclear DNA
what do ovaries secrete?
estrogen
All embryos have the capability to produce how many internal ductwork systems? name them
2 ductwork systems.
- Mullerian ducts
- Wolfian ducts
the Mullerian ducts become the ________ internal anatomy and the Wolfian ducts become the _____ internal anatomy.
- female
- male
How many of the chromosomes that come from your mom and your dad are autosomal chromosomes?
44 autosomal chromosomes
MIF/MIS causes which ducts to regress?
Mullerian ducts
testosterone causes the Wolfian ducts to become what 4 structures?
- epididymis
- vas deferens
- seminal vesicles.
define autosomal chromosomes
chromosomes that determine your general characteristics as a human such as eye color, nose shape, personality, etc.
what promotes the development of the penis and scrotum?
testosterone
True or false
a system that contains MIF/MIS and testosterone will develop into a female and a system without testosterone will develop into a male.
false,
contains MIF/MIS and testosterone will develop into a male
system without testosterone will develop into a female.
how many chromosomes are sex chromosomes?
two (one from mom, one from dad)
what aids in the development of secondary sexual characteristics such as male body type, thicker skin, deeper voice, and specific pattern of hair growth on the body.
testosterone
Dads can give an X or Y chromosome but Moms can only give an X chromosome (T/F)
TRUE
estrogen promotes female secondary sexual characteristics such as what?
- body type (wider hips, higher fat percentage, breasts)
- thinner skin.
external genitalia become the penis and scrotum in the 1. (presence OR absence?) of androgens such as testosterone and become the clitoris and labia in the
2. (presence OR absence?) of androgens.
- presence
- absence
True or false
Wolfian ducts which become the male internal reproductive structures persist in the presence of androgens and regress without androgens. Mullerian ducts which become the female internal genitalia regress in the presence of MIF/MIS and persist in the absence of MIF/MIS.
true
basic pathway for sperm movement out of the male reproductive tract
Seminiferous tubules
V
epididymis in the testes
V
through the vas deferens
V
into urethra
V
through penis
V
out of body
where does the basic pathway of egg movement through the female reproductive tract start and what is produced there?
at the ovaries where eggs are produced.
Eggs are released from the ovaries directly into what in females?
abdominal cavity
What structure gently wafts over the surface of the ovary and create a negative pressure which helps to pull the ovum into the uterine tube (Fallopian tube).
fimbrae
where are spermatozoa cells made
seminiferous tubules
If fertilization occurs, it usually occurs in which tube?
uterine tube
Where are testes located and what develops there?
in the scrotum where sperm develop
If the egg is fertilized it travels down the uterine tube to the uterus where ____________ into the endometrial lining of the uterus occurs.
implantation
If the egg is not fertilized, it then travels through the ______ into the vagina and out the body of the female.
cervix
Why are the testes located outside the abdominal cavity of the male in the scrotum?
the optimal temp for sperm development is about 3 degrees cooler than body temperature.