Chapter 15 - Production Of Sex Cells Flashcards Preview

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Flashcards in Chapter 15 - Production Of Sex Cells Deck (53):
1

What are gametes?

Sex cells

2

What are gonads?

Organs that produce sex cells

3

What is a diploid cell?

A somatic cell that contains 46 chromosomes.

4

What is a haploid cell?

A sex cell that contains 23 chromosomes.

5

What is the product of mitosis?

Diploids for growth and repair.

6

What is the product of meiosis?

Gametes for sexual reproduction.

7

What is a zygote?

The product of fusion of the male and female gametes at fertilisation.

8

What are the male gametes?

Spermatozoa

9

What are the female gametes?

Ova

10

What does sexual reproduction involve?

The joining together of gametes

11

What are primary sex organs?

The organs that produce gametes.

12

What are secondary sex organs?

Organs that store gametes, bring them together for fertilisation and support the developing baby

13

What are the male primary sex organs/gonads?

Testes

14

Where are the testes located?

In a skin covered pouch called the scrotum which is the supporting structure for the testes

15

Why do the testes lie on the outside of the body cavity?

Because the production and development of sperm requires a temperature about 2 degrees lower than body temperature.

16

What happens when the testes are too cold/hot?

Smooth muscles fibres contract to move them closer or further away from the body

17

What is the structure of the seminiferous tubules?

200-300 lobules

18

What is the function of seminiferous tubules?

Lined with cells that divide during spermatogenesis to produce male gametes

19

What is the function of interstitial cells?

Secrete testosterone

20

What is the function of the epididymis?

Stores sperm and transports in from the testes to the vas deferens

21

What does sperm require?

- a watery medium in which to swim
- a nourishing environment that provides sugars they need
- protection against the acidic environment of the vagina

22

What does semen do?

Nourishes and aids the transport of sperm

23

What is the function of the vas deferens?

Carries sperm away from testes and connects with the urethra

24

What is the function/structure of the seminal vesicles?

- pair of pouch like glands
- secrete a thick, sugary fluid that makes up 60% of sperm

25

What is the structure/function of the prostate gland?

- single gland, shaped like a donut
- where the two vas deferens join the urethra
- secretes a thin, milky, alkaline fluid that also becomes part of semen

26

What is the function/structure of the bulbo-urethral glands?

- two small yellow glands the size of a pea
- secretes clear lubricating mucus
- much of the secretion precedes the emission of seminal fluid

27

What is the glans covered by?

The foreskin

28

What does the penis contain?

Connective tissue called erectile tissue

29

What are the functions/characteristics of erectile tissue?

- rich blood supply
- has a large number of sponge like spaces
- during intercourse the spaces fill with blood which causes the penis to stiffen, enlarge and become erect

30

What is the function of the ovaries?

Produce ova and hormones

31

What is each ovary composed of?

A mass of connective tissue called stroma, which is surrounded by a layer of cells containing numerous germ cells

32

What are germ cells enclosed in?

A follicle

33

What is the function of the uterus?

Holds, protects and nourishes the developing baby during pregnancy

34

What is the function of the cervix?

Directs sperm into the uterus during interocurse

35

What is the function of the vagina?

Receives the penis during intercourse and acts as a birth canal

36

What is the function of the labia minora?

Surround the space into which the vagina and urethra open

37

What is the function of the labia majora?

Contains glands that produce an oily secretion

38

What is the function of the clitoris?

Contains erectile tissue that becomes engorged when stimulated

39

What is the function of the uterine tubes?

Carries eggs from the ovaries to the uterus

40

What is the function of the fimbriae?

Directs ova into the uterine tubes

41

What holds the ovaries in place?

Ligaments

42

What are the seminiferous tubules lined with?

Immature cells called spermatogonia

43

What happens to spermatogonia at puberty?

They begin to divide by mitosis and in doing so provide a continuous source for the production of new sperm

44

What happens to the daughter cells of spermatogonia before they undergo spermatogenesis?

They are pushed inward to the centre of the tubule, where they undergo a period of growth

45

What are primary spermatocytes?

Cells that undergo the first stage of meiosis to produce secondary spermatocytes

46

What is the final stage of spermatogenesis?

When the spermatids mature into spermatozoa

47

When does spermatogenesis start occurring?

At puberty

48

How long does spermatogenesis take?

From spermatogonium to spermatozoa, 72 days

49

What are egg mother cells called?

Oogonia

50

What are primary oocytes surrounded by?

Primary follicle

51

What is the order of the development of ova?

Oogonia - primary oocyte - secondary oocyte - ootid - mature ovum

52

That are the products of the primary oocytes dividing in the first stage of meiosis?

- secondary oocyte
- first polar body

(Two cells unequal in size)

53

What does the secondary oocyte immediately start to do?

Commences the second division of meiosis, stopping at metaphase.
At this stage the follicle ruptures and ovulation occurs, and if fertilisation occurs the final meiosis division occurs, producing a mature ovum