UNIT 3 CHAPTER 42-HUMAN REPRODUCTION

Question 0

what is ejaculation ?

Answer 0

it is the release of semen from the penis

Question 1

what is a gonad ?

Answer 1

it is an organ that produces sex cells in animals

Question 2

what are secondary sexual characteristics ?

Answer 2

they are those features that distinguish males from females, apart from the sex organs themselves

Question 3

what is infertility ?

Answer 3

it is the inability to produce offspring

Question 4

what is ovulation ?

Answer 4

it is the release of an egg from the ovary

Question 5

what is the menstrual cycle ?

Answer 5

it is a series of events that occurs every 28 days on average in the female if fertilisation has not taken place

Question 6

what is insemination ?

Answer 6

it is the release of semen into the vagina, just outside the cervix

Question 7

when does fertilisation occur ?

Answer 7

it occurs when the nucleus of the sperm fuses with the nucleus of the egg, forming a diploid zygote.

Question 8

what is birth control ?

Answer 8

it refers to methods taken to limit the number of children that are born,
examples:
abortion and contaception.

Question 9

what is abortion ?

Answer 9

it is the termination of a pregnancy .

Question 10

what is contraception ?

Answer 10

it is the deliberate prevention of fertilisation or pregnancy .
there are 4 types:
-natural
-mechanical
-chemical
-surgical

Question 11

what is implantation ?

Answer 11

it is the embedding of the fertilised egg into the lining of the uterus.

Question 12

what is a morula ?

Answer 12

it is a solid ball of cells formed from a zygote by mitosis

Question 13

what is a blastocyst ?

Answer 13

it is a hallow ball of cells formed from a morula.

Question 14

what are germ layers ?

Answer 14

they are basic layers of cells in the blastocyst from which all adult tissues and organs will form.

Question 15

what is gestation ?

Answer 15

it is the length of time spent in the uterus from fertilisation to birth.

Question 16

what is lactation ?

Answer 16

it is the secretion of milk by the mammary glands(breasts) of the female.

Question 17

what do the testes do ?

Answer 17

the testes produce sperm and testosterone

Question 18

what do sperm ducts do ?

Answer 18

they carry sperm to the urethra in the penis.

Question 19

what does testosterone do ?

Answer 19

testosterone causes:

• the primary male characteristics (growth of the penis and descent of the testes from the body cavity),
• the secondary male characteristics (increased body hair, enlargement of the larynx, muscle and bone growth).

Question 20

what are the average events of the menstrual cycle ?

Answer 20

~Days 1-5= Menstruation (loss of endometrium), meiosis occurs in the ovary, forming a new egg in the Graafian follicle.
~Days 6-14= The endometrium thickens (due to oestrogen).
~Days 14= Ovulation (i.e, an egg is released from the Graafian follicle in the ovary).
~Days 14-28= The endometrium continues to develop; the egg dies by day 16 if it is not fertilised .

Question 21

what are fibroids ?

Answer 21

they are benign tumours of the uterus.

Question 22

how are fibroids treated ?

Answer 22

they are not treated if they are small but if they are big then they can be surgically removed.

Question 23

what does the placenta do ??

Answer 23

it separates the blood of the embryo and the mother.

Question 24

what are the functions of the placenta ? (in reference to the exchange of materials).

Answer 24

~oxygen, food, antibidies, drugs, some hormones and micro-organisms entering the embryo.
~carbon dioxide, salts, and urea entering the mother.