Sex Determination Flashcards
a category we are assigned to based on biological attributes relating to how we reproduce
Sex
What are the attributes that assign sex?
Gonads, Reproductive cells, Hormones, Anatomy, physiology, behavior, pheromones, etc.
What are gonads?
Testes or ovaries, or both
What are reproductive cells?
Eggs or sperm
It’s how our bodies come to have the biological attributes
Sex determination
Is there a primary sex determination?
No
What are the two kinds of sex determination
Asexual and sexual
Reproduction where some organisms can reproduce without having any fertilization taking place
Asexual
What are two ways reproduction can be asexual?
Adult organism splits into two or more parts, single adult produces cells that are specialized for reproduction
Name an example that can split into two
Anemone
What is the way of no sex determination?
Asexual reproduction
What types of hormones does the male and female get?
Testosterone for males and estrogens for females
What determines a person’s sex?
Gonads
What is the function of hormones?
They determine how the rest of the body responds and how to be a certain sex
What are the sexual characteristics that our hormones create in sex determination?
Anatomy, physiology, pheromones, and behavior
T/F: There is a primary sex determination
False
What are the two scientific names of reproduction that is “no reproduction?”
Asexual and Simultaneous Hermaphrodite
Name two animal examples of Parthenogenesis eggs?
Amazon Mollies and Whiptail Lizards
How do Amazon Mollies reproduce?
Asexual. Pathogenesis. kind of fish that are related to other kinds of mollies. Most mollies reproduce sexually, but there are no male amazon mollies. They are all female. they mate with males of a Different mollies species and don’t use sperm. the babies are genetically identical to the parent, and the sperm that is required are not genetically involved; dad is not related in any way
How do whiptail lizards reproduce?
Asexual. Pathogenesis. Don’t require sperm, but do require behavior of mating. they form pairs, one performing the role (biting neck, wrapping around each other, and releases eggs and ovulates). the other switch roles and does the same as well. no males or females. They look like eggs but they’re not really
What is a Simultaneous Hermaphrodite?
All individuals are both male and female at the same time and produce both eggs and sperm at the same time
Name the five versions of a Simultaneous Hermaphrodite
Ovotestes, Separate male and female organs, Flowers, Self Fertilization, and Self-Incompatible
Name an animal example of a Simultaneous Hermaphrodite?
Nematode. It has separate male and female organs, self fertilizes, and sometimes has to mate with somebody else.
What determines the kinds of gonads an individual makes?
No sex determination, chromosomes, environment, and social environment
What are the attributes of the nematode?
•Simultaneous hermaphrodite –Separate ovaries & testes –Hermaphrodites can fertilize themselves –Hermaphrodites can be fertilized by males •Sex determination genetic –Hermaphrodites XX –Males XO
How many chromosomes do bees have?
Males have 16, females have 32
What all is involved in the environment that can determine a sex?
Temperature, day length, humidity, Salinity, and nutrition
What determines a turtle’s sex in temperature?
Low T - male
Hight T - female
What all is involved in a social environment that can determine a sex?
Host, population density, proximity to females, availability of mates
Name an example of a proximity to females in a social environment
Anglerfish
Name an example of availability of mates in a social environment
Anemone clownfish, bullheaded wrasse, gobe
Poor environmental and social conditions favor what gender?
Male
Favorable environmental and social conditions favor what gender?
Female
What determines the kinds of gonads an individual HUMAN makes?
Chromosomes
How many pairs of chromosomes are in a human?
23 pairs
What gene is involved in the male’s sex determination?
SRY gene
Describe the Pathogenesis way of asexual reproduction
A whole adult body splits into two more individuals
What is a Hermaphrodite that has Ovotestes?
makes eggs and sperm at the same time
Name an animal that has separate male and female organs
Nematode
T/F: most flowers are hermaphrodites
True
What is a Hermaphrodite that is self-incompatible?
Have eggs and sperm, but have to mate with somebody else
How many chromosomes are in a single cell?
23
Which chromosome does the SRY gene make?
Y
What percentage do uncommon/intersex variation of humans make?
2%
What percentage do the variation of xy males and xx females make of the population?
98%
What are the most common genetic variations in biological gender determination?
What are the other three possibilities?
SRY translocation, Klinefelter’s Syndrome, Turner’s Syndrome
XYY, XXX, Mosaic/true hermaphrodite, and YY (not as possible)
Describe SRY Translocation
cross positioning of Y chromosome
Describe Klinefelter’s Syndrome
2 X chromosomes and one Y chromosome, slightly feminized male
Describe Turner’s Syndrome
one X chromosome and no second chromosome, infertile
What is a Mosaic/true hermaphrodite
different parts of your body have different chromosomal counts
Part of your body could be XX and other part XY
Very uncommon
What are the characteristics of male sperm?
Abundant, Cheap to Make, Small, Motile
What are the characteristics of female eggs?
Nutrient rich, Easy to find, Large, Limiting
What parts of the internal reproductive system in males does testosterone help produce?
epididymus, vas deferens, seminal vesicles, ejaculatory ducts
What are the hormonal variations in biological gender determination?
Androgen Insensitivity Syndrome
5-alpha reductase deficiency (Guevedoces Syndrome)
What is Androgen Insensitivity Syndrome
The SRY gene makes the gonads testes but other parts of the body don’t have the receptors to respond to testosterone
They have xy chromosomes and have sexes, they don’t develop any of the internal structures or the external structures that make them look male to us
What are the three hormones in male reproduction?
Testosterone, Anti-Mullerian Hormone, 5α-dihydrotestosterone (DHT)
What does the Anti-Mullerian Hormone do?
degeneration of ♀ internal reproductive system
–Produced by gonad if SRY is present
- causes the tube that would form the uterus to break down
What does 5a-dihydrotestosterone (DHT) male hormone do?
produce external reproductive genetalia
What is 5-alpha reductase deficiency (Guevedoces Syndrome)
- “penis that swells”
- fairly common in dominican republic
- missing that one chemical but the transition can occur to a male
What is Androgenital Syndrome?
testosterone is sometimes produced in much higher amounts than usual due to feedback with pituitary glands in the base of brain
in males it often leads to early puberty and hyper masculinized anatomy
if it happens in a XX baby, it often results in development of a penis or micropenis, or in between a clitoris or penis
The absence of male hormone cause what?
female organs
What does the lack of 5a-dihydrotestosterone (DHT) male hormone produce?
Female external genetalia
What are the secondary sexual characteristics of a human produced?
Anatomy, pheromones, behavior, and health
Pheromones
chemicals that our bodies makes that are on our skin, and other people can respond to them
