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Flashcards in Jones - reading Deck (45)
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1

What is fitness?

Survivors selected by ability to reproduce

2

What is the gene pool constantly doing?

Adapting

3

What is the purpose of reproduction?

Pass genes to next generation

4

How do most organisms reproduce?

asexually

5

How do unicellular organisms reproduce?

mitotically - produce two identical offspring

6

how do complex vertebrates reproduce?

Partenogenesis - egg cell doesn't need sperm to become an embryo

7

How do mammals reproduce?

sexually

8

what is produced at fertilisation?

zygote

9

what is the function of meiosis?

halves genetic material
produces germ cells

10

How do mammals increase genetic diversity?

exchanging pieces of homologous chromosomes

11

What is a mechanism of recognising fitness in mammals?

sexual selection

12

Negatives of sexual selection

Energy expenditure in finding, attracting and keeping a partner
exposure of both partners to death

13

Why do mammals reproduce by internal fertilisation?

Reduced number of eggs - energy expenditure
women undergo egg loss but mainly before egg growth

14

What is viviparity?

production of smaller eggs
development in vivo
birthing live young

15

Positives of viiparity?

reduces pressure to develop quickly

16

negatives of viviparity?

long gestation is demanding on females
there is a selective pressure on birthing as it can go wrong

17

How long do mammals display parental care for?

An extended period

18

What is fercundity?

reproductive capacity

19

How does fercundity differ in males and females?

Males - persists throughout life, slowly declines
Females - declines steeply at 35, ends at 50, due to loss of egg quality

20

Male contraception using testosterone levels

High testosterone leads to FSH stimulating spermatogenesis
could suppress endogenous testosterone production and therefore spermatogenesis
Shown as effective in some people - less in others
took a long time to get a low sperm count in some people

21

Male contraception using small molecule inhibitors of BRDT

BRDT= testes specific epigenetic reader protein
JQ1 = BRDT inhibitor - targets bromodomain and prevents recognition of acetylated H4
reduces sperm number and motility without altering hormones
reversible withing 1 month

22

Male contraception PLC3

Potential to inhibit PLC3 and prevent oocyte activation
no specific molecules found yet

23

female contraception Target the zona pellucida

immuniation of zona pellucida
this may cause abnormal cycles

24

Male contraception
Binding to the androgen and progesterone receptors

reduces testosterone conc in blood
effective and reversible
no serious side effects
weight gain

25

Male contraception
Adjudin

disrupts spermatid adhesion to sertoli cells
premature spermiation - not mature enough to fertilise

26

Male contraception
Retinoic acid receptor antagonists

Aldehyde dehydrogenase in setoli cells synthesises retanoic acid
this is required for spermatageneis

27

Male contraception
Synthetic androgens

Supress gonadorophins and sperm production
reversible
may be incomplete suppression

28

Male contraception
Nestorone and testosterone gel

Progestin compound
blocks testosterone production and reduces sperm production
targets sertoli germ cell adhesion or sperm motility

29

Male contraception
Vasalgel

Reversibly blocks vas deferens
prevents passage of sperm
impairs sperm function
reversible

30

Male contraception
Block to sperm delivery

100% efficacy after 15 days
attaches to cells in vas deferens and blocks sperm passage
leads to morpholically different sperm