Reproduction In Humans

Question 1

Definition of asexual reproduction

Answer 1

It is the process resulting in the production of genetically identical offspring from one parent, without the fusion of gametes.

Question 2

Definition of sexual reproduction

Answer 2

It involves the fusion of two gametes, one from each parent to form a zygote. It produces genetically dissimilar offspring

Question 3

Function of testis

Answer 3

1. Production of sperms

2. Production of male sex hormones

Question 4

Function of scrotum

Answer 4

1. Holds the testes outside the main body cavity for optimal sperm development.

Question 5

Function of sperm duct

Answer 5

1. Transports the sperms from the testes to the urethra.

Question 6

Function of glands

Answer 6

The prostate gland, seminal vesicles and the Cowper’s gland secrete a fluid which mixes with the sperms( containing nutrients and enzymes which nourish the sperms and stimulate them to swim actively)

Question 7

Function of the urethra

Answer 7

Transports semen from the sperm ducts and urine from the urinary bladder out of the body.

Question 8

Function of penis

Answer 8

It erects and enters the vagina during copulation

Question 9

Function of ovaries

Answer 9

1. Production of eggs

2. Production of female sex hormones

Question 10

Function of oviduct

Answer 10

1. Site of fertilization

2. Transports the zygote to the uterine lining

Question 11

Function of uterus

Answer 11

1. Implantation of embryo onto the uterine lining

2. Site of fetus development

Question 12

Function of cervix

Answer 12

1. It dilates during labor, allowing the fetus to pass through

Question 13

Function of vagina

Answer 13

1. Semen is deposited in the vagina during sexual intercourse

Question 14

Process of Fertilization

Answer 14

1. The egg released from a ovary is surrounded by a few layers of follicle cells
2. In order to penetrate the egg, the a rosins if the sperm releases an enzymes to digest the follicle cells
3. Only in sperm nucleus fuses with the haploid egg nucleus to form a diploid zygote.
4. As soon as the sperm has entered the egg, the membrane of the egg becomes impervious to other sperms. The remaining sperms eventually die.

Question 15

Development of embryo

Answer 15

1. The zygote divides itself by mitosis to form embryo.

2. Eventually, the embryo become embedded in the uterine lining(implantation) usually 7days after fertilization.

Question 16

Function of aminotic sac and aminotic fluid

Answer 16

Amniotic fluid:

1. It acts as a shock-absorber to protect the fetus from mechanical injuries
2. During labor, it lubricated and reduces friction in the vagina

Amniotic sac:
1. Enclosed the fetus in an amniotic cavity filled with amniotic fluid

Question 17

Function of the placenta

Answer 17

1. It allows oxygen and food substances to diffuse firm the mother’s blood into the fetal blood
2. It allows excretory products to diffuse from the fetus blood into the mother’s blood.
3. It allows protective antibodies to diffuse from the mother’s blood into the fetal blood

Question 18

Functions of the umbilical cord

Answer 18

1. 2 umbilical arteries that transport oxygen poor blood and excretory products from the fetus to the placenta
2. 1 umbilical vein that transports oxygen rich blood and digested food substances from the placenta to the fetus

Question 19

Mode of transmission for Human Immunodeficiency virus

Answer 19

1. Unprotected Sexual intercourse with an infected person
2. Sharing hypodermic needles with an infected person
3. Blood transfusion with an infected person
4. During pregnancy, breast milk

Question 20

The menstrual cycle

Answer 20

For a 28-day cycle:
Day 14: ovulation
Fertile period: day 11-16

Sperms can survive for 3-4 days
Egg can survive for 1-2 days

Question 21

Function of oestrogen

Answer 21

1. It causes the repair and growth of the uterine lining

* both cause secondary characteristics to develop

Question 22

Function of progesterone

Answer 22

Prepares the uterine lining for pregnancy:

1. Cause it to be further thickened
2. Supplying it with blood capillaries