Overview of reproduction in domestic animals

Question 1

What is Progeny?

Answer 1

A descendent from an animal, can be used for meat production, or non-breeding functions

Question 2

What is the definition of Sexual reproduction?

Answer 2

Fusion of the haploid genetic complements from 2
distinct gametes (ovum and spermatozoon) at fertilisation to form the genetic basis of a novel individual.

Question 3

What are primary sexual characteristics?

Answer 3

Gonad and gamete types

Question 4

What are secondary sexual characteristics?

Answer 4

Appearance// behaviour of the individual

Question 4

What are secondary sexual characteristics?

Answer 4

Appearance// behaviour of the individual

Question 5

What animals have sex determined after fertilisation?

Answer 5

reptiles, amphibians fish etc.

Question 6

What is TDF?

Answer 6

testes determining factor

Question 7

What gene helps translate TDF?

Answer 7

SRY gene

Question 8

What are the two key cell types in the intermediate gonad?

Answer 8

Mesoderm and primordial germ cell

Question 9

What is the male Indeterminate tubular reproductive tracts

Answer 9

wolfian

Question 10

What is the female Indeterminate tubular reproductive tracts

Answer 10

Mullerian

Question 11

What are the 3 different types of somatic cells in the male gonad?

Answer 11

Supporting cells, Endocrine cells and Connective tissue cells

Question 12

What are the male and female supporting cells respectively

Answer 12

Sertoli cells and ovarian follicle cells

Question 13

What are the male and female endocrine cells respectively?

Answer 13

Leydig and Thecal cells

Question 14

What cells produce testosterone in a female?

Answer 14

the Thecal cells

Question 15

What does testosterone in females then go on to stimulate?

Answer 15

oestrogen production which stimulates the mullerian duct

Question 16

What are the two main effects of testosterone in males?

Answer 16

Development of secondary sex characteristics

Question 17

What do sertoli cells produce?

Answer 17

Mullerian inhibiting factor which actively prevents the mullerian duct from forming

Question 18

What is freemartinism?

Answer 18

When some of the blood from a male twin leaks over to female (TDF) which leads to sterility in the female

Question 19

What does GnRH do?

Answer 19

it acts directly on anterior pituitary cells to stimulate LH and FSH release into the systemic circulation

Question 20

Where is GnRH released from?

Answer 20

The hypothalamus

Question 21

What does LH do in males?

Answer 21

causes the testicles to make testosterone

Question 22

What two centres does a female have in the hypothalamus?

Answer 22

Surge and tonic

Question 23

What does dioecious mean?

Answer 23

Animals that exist as one of two sexes

Question 24

What are the two ways of determining sex?

Answer 24

Environmental which occurs after fertilisation and genetic which occurs at fertilisation

Question 25

How is the development of the surge centre stopped in males?

Answer 25

Testosterone does not bind to F2 alpha, this means that it can enter the brain and be converted into estrogen which in turn prevents the surge centre form being developed

Question 26

What stimulates the development of follicle cells from the pre-follicular cells?

Answer 26

At around 12 weeks in females, the PGC's begin to produce oocytes by meiosis of germ cells, this stimulates the development of follicle cells

Question 27

Why are oocytes not produced in males?

Answer 27

With the addition of TDF, pre-sertoli cells are converted into spermatogenic cords, these inhibit meiosis in germ cells

Question 28

What is the effect of free-martinism on the female?

Answer 28

90% are sterile

Question 29

What influences biological efficiency?

Answer 29

Reproduction efficiency, Lactation ability, Growth and development, replacement rate and longevity

Question 30

When is TDF translated?

Answer 30

Following expression of the SRY gene

Question 31

What cells does TDF act on?

Answer 31

Somatic cells to create an appropriate environment to support sex specific gametogenesis

Question 32

What do sertoli cells become under the influence of TDF?

Answer 32

spermatogenic cords that then inhibit meiosis of PGC's

Question 33

What is the function of the germ cells?

Answer 33

They differentiate into the gametes (spermatozoa or ovum)

Question 34

What is the name of the cells that produce mullerian inhibiting factor?

Answer 34

Sertoli cells

Question 35

Explain how the production of the surge centre in females is controlled

Answer 35

Estrogen is produced which then binds to a protein called alpha fetal protein which means it cannot enter the hypothalamus In males testosterone is produced and enters the hypothalamus where it is then converted into estrogen and prevents the surge centre from being produced