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Flashcards in Sex Development Deck (107)
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1

Why Sex?

Allows for introduction of genetic variation to propagate new genetic traits

2

Sexual reproduction benefits organisms who live in what type of environment

Exist in a constantly changing environment

3

Sexual reproduction benefits organisms who encounter what? And need to what?

Encounter bacteria, viruses, and parasites, and need to fend off disease

4

Sexual reproduction benefits organisms who need to purge what?

Deleterious mutations

5

Sexual reproduction - 2 levels of variation

- each parent share's half genome via independent assortment
- recombination during meiosis

*note also that specific point mutations can occur that can confer advantage (or disadvantage) evolutionarily

6

What is sexual dimorphism?

The phenotypic difference between males and females -
includes reproductive organs as well as body habitus

7

Sex chromosomes anueploidy leads to

Disorders that don't have the normal number of X or Y chromosomes

8

Now matter how many X chromosomes you have, how many X chromosomes are active?

There is only one active X chromosome, no matter how many X chromosomes you have...
Thus,
46,XX
47,XXX
47,XXY
48,XXYY
all only have one active X chromosome

9

Turner Syndrome
Chromosome constitution

45, XO

10

Turner Syndrome
Signs at birth

Prenatal cystic hygroma - cyst-like cavity filled with lymph
Webbed neck
Puffy hands and feet
Head defects
Coarctation of the aorta

11

Turner Syndrome
Stature?

Short Stature

12

Turner Syndrome - intelligence?

Normal - sometime targeted learning disabilities

13

Turner Syndrome - fertility?

Infertile due to non-functioning ovaries

14

Turner Syndrome - hormones?

Hormone dysfunction - need hormone treatment for secondary puberty

15

Turner Syndrome - distinctive features?

Low set ears - broad chest

16

Turner Syndrome - incidence?

1/2,500 newborn girls

17

Kleinfelter Syndrome
Chromosome Constitution

47, XXY

18

Kleinfelter Syndrome - childhood and learning?

Can be seen -->
Learning disabilities
Delayed speech and language
Tendency toward being quiet

19

When does Kleinfelter become obvious?

Becomes more obvious as puberty - sometimes not even detected until infertility issues arise?

20

Kleinfelter statures?

Tall

21

Kleinfelter genital issues?

Small testes
Hypospadias - opening of urethra is on underside of penis

22

Kleinfelter - body habitus and hair?

Reduced facial and body hair
Gynecomastia
Feminized body habitus

23

Kleinfelter - incidence?

1/500 - 1/1000 newborn boys

24

What is 47, XYY?

Jacobs Syndrome

25

What is Klinefelters chromosome constitution?

47, XXY

26

Jacobs syndrome clinical features (6)

Learning disabilities
Speech delays
Developmental delays
Behavioral and emotional difficulties
Autism Spectrum disorders
Tall stature

27

Incidence of Jacobs Syndrome?

1/1000 newborn boys

28

So what is Jacobs vs. what is Klinefelters?

Jacobs = 47, XYY
Klinefelters = 47, XXY

29

What is 47,XXX called?

Triple X syndrome

30

What kind of stature do Triple X syndrome people have?

May have tall stature