Chapter 3 Flashcards

Question

Female - Ovaries Formation

Answer 1

XX results in formation of ovaries ○ Ovaries secrete low levels of hormones ○ Need certain genes and hormones to feminize ○ The ovaries results in feminization of external genitalia, brain feminization, mullerian duct develops

Answer 2

Chromosomal sex: XX or XY (others...) Gonadal Sex: ovaries or testes hormonal sex: estrogen to androgen ratio Morphological sex: differences in body, external genitalia, coloration (if you have estrogens that can be the feminization of tissue) Behavioral sex: male vs. female behavior

Answer 3

most males are XY - Have a SRY gene - that individual will develop a testes - That would cause high levels of testosterone High testosterone levels masculinizes brain and peripheral tissues

Answer 4

***lack of androgen - the gene that produces the androgen receptor are on X chromosome is mutated **person is XY - Females have two X chromosomes so if there's a mutation, they can still have androgen receptor ***Males who have androgen mutation, have a problem because only 1 X chromosome female (XX - can be carrier for the gene) male (XY - the affected person)

Answer 5

- Chromosomal, they're more male because they have SRY which produces the testes - If you have a non-functional androgen receptor, the body will be feminized - Brain will be feminized - **these people are still XY, have testes, and high levels of tesosterone - They look female, behave as female - *they are infertile because they have testes ***nonfunctional androgens receptors

Answer 6

people with this condition have external sex characteristics of females, but don't have a uterus so they can't have kids ***they look like females - they are usually raised as females and have a female gender identity - they have undescented testes (located by their stomach) - when tesosterone is converted into estrogen, the estrogen makes breasts grow

Answer 7

rare inherited autosomal recessive disorder from deficiency of an enzyme needed to make specific hormones - affects the adrenal glands by making 3 different hormones: - corticosteroids (body's response to illness) - mineralcorticoids (regulate salt and water levels) - androgens ***caused by deficiency of enzyme 21-hydroxylase) in adrenal gland - makes adrogens - these people lack hydroxylase so you have a deficiency in glucocorticoids - since you have excess in progesterone, preogesterone is now considered an androgen bc the pathway is shut down and you make a lot of it

Answer 8

chromsomes: XX (female) - gonads make ovaries prenatal hormones: - towards male - masculinized internal genitalia, external genitalia, brain structures High levels of androgens if you lack enzyme - This causes masculinization ***more variations in how much people are masculinized (in Androgen sensitivity - not as much variation)

Answer 9

- Compromised stress hormones - Results in issues with fertility and sometimes ambiguous genitalia (depends on amount of androgens produced) - Hormonally related -- many issues can be treatable by giving agonists or antigonists - many ppl with this have big adrenal glands that make higher amounts of androgens - females with CAH will most likley have ambigious external genitalia

Answer 10

**most diagnosis for this happen in females flies: number of chromosomes determines sex (just the number) humans: determined by the presence of a Y chromosome XO (turner) XXY (Klinefelter)

Answer 11

sex chromosomes can determine whether the individual is likely male or female - if you're XY, it doesn't mean you're going to end up with a masculinized **23 total chromosome pairs

Answer 12

XO - chromsomes (One X and that's it) ***effects development in females - most are infertile - if you don't have a Y chromsome then you don't have testes, no SRY - causes issues in height - web of skin - the ovaries develop at first, but then the eggs will die (need 2 X chromosomes for fertility) - some people don't go thru puberty, but they can get treated with hormone therapy - can have neck issue

Answer 13

2 X chromosomes and 1 Y chromosome - feminization or demasculinization (males) - hypogonadism - sometimes they can have weaker muscles - symptoms can be mild (like less facial hair) ***More common than Turner's Syndrome - a lot of these men don't ever get diagnosed with it **really common sex chromosome disorder

Answer 14

XYY - when a male receives an extra Y chromosome - typical to be taller, lower muscle tone, curved pinky (clindoactlyly) - more acne - there's so few genes on the Y chromsome that there might not be any big differences or it might be subtle *some boys might have delayed social, language, and learning skills

Answer 15

XX chromosomes with an SRY gene - usually caused by unequal corrsing over between X and Y chromsome during meisois in the dad -- the X chromosome now has SRY *if you have SRY gene, you have testes - most symptoms are related to fertility - hypospadias is observed: hole at top of urethra isn't open - But most people have normal penis and their testes are fine

Answer 16

XXX - female - not a lot of differences in these people **they can have children Triple X happens during division of a parent's reproductive cells - not really differences in these people - might be taller than average *most people with triple X can have kids

Answer 17

XXXX Chromsomes these people are still okay - might have some reduced fertility and might have some facial/dental abnormalities - some people might not have symptoms **this only happens in females (no Y chromosome present) *reduced fertility

Answer 18

XXXXX - when you have 5 chromsomes, you start to see more symptoms - very rare - can start to have cognitive and social issues - reduced fertility

Answer 19

can start with XY or XX - if non-disjunction, the chromosomes are supposed to separate but they don't (both go into the sperm) --- if nothing goes in, you can get XO (turner) *if both go in, you can get XXY (klinefelters) other way: - when nondisjunction happens for females - can't live without an X chromsomes - you can live without a Y chromosome **if you get only Y chromosome, you can't live

Answer 20

they looked at the opiod system dopamine: seeking behavior (anticipation - why we want to do something) opioids: the pleasure/reward we get from the activity wanting = dopamine liking = opioids ex: athletes listen to music before games because it motivates them but also gives them an edge that can reduce endorphins - our brain produces opioids - we have opoid receptors - people who run release opiods

Answer 21

music is pleasurable bc it causes the release of opoids like enkephalin *if you block enkephalin, the body no longer enjoys music

Answer 22

hormone cause differences in the brain ex: female rats have mensteraul cycle - male don't differences in endocrine system in female and male rats (important that there is a diff. bc the female releases the egg - their cognitive systems don't have big differences (no purpose in diff. sex having differences in problem solving)

Answer 23

chromosomes (XXY) - then gonads make testes - then prenatal hormones (hormonal sex: male) - internal genitalia, external genitalia, and brain structures

Answer 24

check for hormones - testes are functional and produce high levels of tesosterone - their physiology is feminized and their behavior is feminized chromsomes --> gonads (testes) prenatal hormones: hormonal sex - high tesosterone

Answer 25

increasing number of X chromosomes in the body can protect you until you get to 5 X chromsomes (penta X) ***Comparing Y and X cells in the brain, there's a balance - Protects against sex differences in the brain ○ The Y chromsome is actually a shrunken X chromosome

Answer 26

There's a system that inactivates one of the chromosomes - ***barr body inside cells = during development, the body silences one of the X chromosomes (for XX person) -- it compacts one of the X chromosomes into a ball ○ This is why you can have 4 X chromosomes and not have an effect because the cell compacts them into barr bodies ***an absence of a barr body means the cell is XY (barr body is when there's 2 Xs and one needs to become inactivated) why have X chromosome inactivation: ***bc there's much more genes on X than Y. chromosome - the imbalance of X-linked genes gets corrected to make sure that the level of gene expression on the X chromosome is the same in both sexes (if a female didn't have X inactivation they would have double the X chromosome gene expression than males bc they only have 1 X chromosome)

Answer 27

calico cats = female (their coloring) Their coloring is from X inactivation - X inactivation happens randomly - But then the cells continue to develop even though the paternal X is inactivated - Male calicos are rare and this is probably because they are XXY ***their pattern of color is based on when the X chromosome was inactivated (males don't have X inactivation bc they have only 1 X chromosome) ***cells can count how many X chromosomes"

Answer 28

Timing: - all cells go thru imprinted inactivation of the X chromosome from the dad in early embryo stage ***the cell immediately recognizes the paternal X and silences it because it doesn't know if the paternal X has disorders - then the tissues that give rise to the placenta keep the imprinted inactivation so only the maternal X is active in these tissues **paternal stays inactive during this ***most contact between baby and mom happen here, so the cell keeps the maternal X active - in the blastocyst, imprinted X inactivation is reversed (both X chromosomes become active again) - each of the cells then randomly inactivates one copy of the X chromosome (sometimes inactivates the paternal X and sometimes inactivates the maternal X)

Answer 29

- Not fully random, we don't fully understand it - The cell at first can recognize if the chromosome is paternal or maternal Random inactivation period: - The cell silences all X but one - Must be a way for the X chromosomes to communicate

Answer 30

- X chromosome doesn't get inactivated if you're XO or XY - If you have 2 Xs, you get 1 barr body - If you have 3Xs, 2 barr bodies (inactivated Xs) and 1 X If you have 4 X chromosomes, 3 get inactiavted and 1 is activated ***number of barr bodies doesn't decide if you will develop as male or female (bc an XXY male will still have 1 barr body and a XX female will still have 1 barr body)

Answer 31

one of the X chromosomes produces a non-coding RNA called XIST (non coding = doesn't produce a protein so it remains an RNA) - XIST silences the X chromosomes - Activated on the inactive chromosome - XIST silences its own X chromosome -it's Non-coding RNA - XIST coats the X chromosome - It's expressed in the middle of the chromosome and then it coats it - Brings another molecule and epigenetically silences the chromosome and produces the barr body

Answer 32

***not coding protein - XIST is expressed from the inactivated X chromosome - since its wrapped around XIST, it stays in the nucleus because that's where it inactivates the extra chromosome - XIST RNA is only expressed in cells containing at least 2 X chromomes ○ Ex: if you're XY, that X doesn't get silenced, so no XIST ○ If you are XXXY, you will have more XIST because you need more X inactivated ***sometimes sex differences in the brain are there to reduce sex differences - Males don't have XIST (sex difference) but XIST works to reduce differences by inactivating extra X chromosomes

Answer 33

One hypothesis: ***The random X inactivation evolved in mammals with placentas to cope with X-linked mutations - the paternal X is always inactivated

Answer 34

***mutation on X chromosome (gene is for regulating neurons) *females that carry a mutated copy of the gene survive (might have symptoms) bc the paternal X has a normal copy of the gene that remains active in the cells - if you're XY, you will have that mutation (usually will die) - if you're XX, there's a good chance you have a cell that will inactivate the effected X chromosome, so you don't have that disorder

Answer 35

***Cells can count, but it can scan and look for DNA mutations and damage (it preferentially silences the damaged cells) *The cells then can inactivate the chromosomes they want to inactivate based on damage (this happens sometimes) = skewed inactivation ○ The body wants to silence that X chromosome Rett's disease in males: lethal - Females can have Rett's but the symptoms can be different - You can have some disorders that are X-linked, but because of skewed inactivation, the symptoms might not be as severe or different

Answer 36

○ The active part is XIST on the inactive chromosome ○ There are other genes too that are active on the inactivated chromosome ○ If you have an inactivated X with 50 genes that are still being expressed, and then you have another fully X chromosome, you don't have twice as many genes - some genes need to stay on because they're needed in both copies of chromosomes (Y chromosome prob has the same gene that is activated in the inactivated x chromosome) - ** This is because the Y chromosome evolved from the X chromosome Y chromosome: - you will see genes that are on the X - this is bc it needs to compensate for the inactivated X chromosome ***Y is still around bc of dosage compensation

Chapter 3 Flashcards

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