4.1 Sexual reproduction in animals (female)

Question 1

What are is the order of follicle in an ovary?

Answer 1

Primary follicle, secondary follicle, Graafian follicle

Question 2

How can a secondary follicle be identified?

Answer 2

It has an antrum

Question 3

What occurs halfway through the menstrual cycle?

Answer 3

Ovulation

Question 4

What does the corpus luteum secrete?

Answer 4

Progesterone

Question 5

What does progesterone do?

Answer 5

Lots of progesterone= everything stays in
Low progesterone= period

Question 6

What part of Oogenesis occurs before birth?

Answer 6

Oogonia divide by mitosis and enlarge to produce primary oocytes, matures
Primary oocyte begins Meiosis 1 but stops at prophase 1

Question 7

What part of Oogenesis happens at puberty?

Answer 7

• One of follicles which has primary oocyte matures, producing Secondary oocyte and polar body
  -Secondary oocyte goes Meiosis 2 but stops at Metaphase 2
  -Ovum is formed but Meiosis 2 only complete if fertilisation occurs

Question 8

What does Lactobacillus secrete?

Answer 8

-Lactic acid
-Maintains low pH to inhibit growth of other microbes

Question 9

What are the cells surrounding the secondary follicle called?

Answer 9

Granulosa cells

Question 10

What are the cells surrounding a follicle after ovulation called?

Answer 10

Corona Radiata

Question 11

What separates the follicle and granulosa cells?

Answer 11

Zona pellucida

Question 12

What happens during Follicular stage?

Answer 12

-Anterior pituitary gland secretes FSH
-FSH stimulates primary follicle to develop into secondary follicle
-Maturing follicle secretes oestrogen

Question 13

What does Oestrogen do?

Answer 13

-Stimulate growth of endometrium and bloody supply increases
-Inhibits FSH, suppressing follicle development
-Stimulates growth of uterine wall
-Stimulates ant/pit to make and store luteal hormone

Question 14

What happens during ovulation?

Answer 14

-Peak oestrogen triggers ant/pit to release Luteinising hormone
-Oestrogen decreases
-Luteinising hormone induces ovulation on day 14
-luteinising hormone stimulates maturation of graafian follicle into corpus luteum

Question 15

What happens during luteal phase if no implantation occurs?

Answer 15

-Corpus luteum secretes progesterone
-Falling levels of FSH and LH cause corpus luteum to degenerate
-Endometrium breaks down
-Progesterone drops and no longer inhibits FSH, new cycle starts

Question 16

What happens during luteal phase if implantation occurs?

Answer 16

-Blastocyst releases HCG which maintains corpus luteum for 16 weeks and stimulates progesterone production whilst placenta develops

Question 17

What does progesterone do?

Answer 17

-Maintain endometrium
-Inhibit FSH and LH

Question 18

What hormones are made by the anterior pituitary gland?

Answer 18

-Luteinising Hormone and Follicle Stimulating Hormone

Question 19

What hormones are made in the reproductive system?

Answer 19

-Progesterone (corpus luteum)
-Oestrogen (Secondary follicle)

Question 20

What hormonal changes occur during pregnancy?

Answer 20

-Embryo secretes HCG to 16 weeks
-Placenta takes over and secretes progesterone and oestrogen, inhibiting LH and FSH
-Progesterone stops contraction of uterus, whilst oestrogen causes uterus and mammary glands to grow
- Progesterone inhibits oxytocin

Question 21

What hormonal changes happen at birth?

Answer 21

1) Just before birth Oestrogen levels increase and progesterone decreases
2) Oxytocin is no longer inhibited, oxytocin stimulates contraction of uterine wall, stimulating secretion pf more oxytocin (positive feedback)

Question 22

How do hormones produce milk?

Answer 22

Prolactin secreted by anterior pituitary gland during and after birth stimulates production of milk by mammary glands