Mammalian Reproduction

Question 1

Explain one function of two hormones that stimulate sperm production

Answer 1

Follicle stimulating hormone- stimulates the production of ANRDOGEN BINDING PROTIEN and formation of blood-testis barrier
Testosterone- development of male reproductive tissues- testis and prostate, promoting secondary sexual characteristics such as increased muscle and bone mass, stimulates Sertoli cells to produce inhibin

Question 2

Levels of hormones change during the oestrous cycle

Answer 2

LH- decreases
FSH- decreases
Oestrogen- decreases
Progesterone- increases

Question 3

How levels of the following hormones change when an animal is giving birth

Answer 3

Oestrogen- increase
Oxytocin- increase
Progesterone- decrease
Prostaglandins- increase

Question 4

The length of the gestation period in a cow

Answer 4

Between 279-287/ 9 months

Question 5

State the three parts of the female reproductive system

Answer 5

Ovaries, uterus, vagina

Question 6

Describe the role of the following hormones in reproduction

Answer 6

Oestrogen- stops FSH production, stimulates pituitary gland to release LH, builds up uterine lining allowing implantation, causes thickening of the endometrium
Oxytocin- stimulated by suckling, bonding of young, stimulates labour, increases prostaglandins

Question 7

Function of the epididymis

Answer 7

Sperm are matured and stored

Question 8

Two functions of the male reproductive system

Answer 8

Produce and store sperm
Release sperm into the female reproductive tract

Question 9

Structure and function of the os penis

Answer 9

Bone found in some species of mammal, used to maintain an erection

Question 10

Three functions of the placenta

Answer 10

Provides nutrients to the foetus
Functions for respiration
An area for excretion

Question 11

State functions of the cervix and uterus

Answer 11

Cervix- provides protection for the reproductive system against infection
Uterus- where fertilised egg implants, stretched to accommodate growth of foetus contracts to expel foetus

Question 12

Which type of uterus does a pig have

Answer 12

Bicornuate

Question 13

Two functions of the female reproductive tract

Answer 13

Produce eggs, provides a place for fertilisation to occur

Question 14

3 layers of the uterus

Answer 14

Perimetrium- outer layer, supports shape of the uterus
Myometrium- muscular layer, contracts
Endometrium- forms the inner lining, where implantation takes place

Question 15

Define terms fertilisation, implantation and gestation

Answer 15

Fertilisation- sperm and egg fuse
Implantation- a fertilised egg attached itself to the lining of the uterus
Gestation- the length of time between conception and birth

Question 16

Roles of hormones

Answer 16

GnRH- controls other reproductive hormones, stimulates the production of LH and FSH

Progesterone- maintains the lining of the uterus ready for fertilised egg, inhibits the production of FSH

Cortisol- linked to increased maternal interest in offspring (stress hormone)

Question 17

Where are the following hormones produced?

Answer 17

Oestrogen- ovaries

Progesterone- corpus luterum, ovaries, placenta

Androgen binding hormone- seminiferous tubules

Oxytocin- hypothalamus

Question 18

What is the corpus luteum?

Answer 18

A sac of cells remaining after the ova had been released during ovulation

Question 19

Describe the milk let down process

Answer 19

Prolactin triggers the mammary glands, stimulates lactation
Oxytocin releases milk and is stimulated by suckling

Question 20

Explain the roles of hormones during parturition(giving birth)

Answer 20

Progesterone levels decrease allowing other hormones to act on the uterus
Oestrogen levels rise leading to uterine contractions and cervical softening
Relaxin is secreted by the ovaries relaxing pelvic ligaments and opening the birth canal
Oestrogen and progesterone levels drop allowing prolactin to be secreted which triggers lactation

Question 21

Describe how levels of hormones change through all stages of the oestrous cycle

Answer 21

Dioestrus is between oestrous cycles and levels of progesterone peak
Pro-oestrous- follicle enlarges, progesterone decreases, oestrogen increases, GnRH is secreted which stimulates the release of FSH and LH
Oestrous- animal is sexually receptive, oestrogen increases as well as FSH and LH leading to ovulation
Metoestrous- corpus luteum decays, progesterone levels increase and inhibits oestrogen release

Question 22

Gametogenesis-

Answer 22

Occurs in the reproductive organs
Process where ova and sperm are produced by CELL DIFFERENTIATION of the germ line
Differentiating haploid daughter cells for the production of functional gametes
2 pathways involved- mitosis and meiosis

Question 23

Roles of hormones 2

Answer 23

Oestrogen- rebuilds the uterine lining after menstruation, stimulates release of LH

Testosterone- produced my tested, enables development of sex organ tissues and secondary sexual characteristics

Androgen binding hormone- produced by seminiferous tubules, helps to maintain high concentrations of testosterone

Prostaglandins- help with uterine contractions

Oxytocin- released by pituitary gland, helps stimulate uteri’s r contractions and lactation