sexual reproduction in humans (male ver.)

Question 1

what is a haploid set of chromosomes?

Answer 1

23 chromosomes (gamete—egg cell, sperm cell)

Question 2

what is a diploid set of chromosomes?

Answer 2

46 chromosomes (zygote—egg cell + sperm cell)

Question 3

what are the parts of the male reproductive system?

Answer 3

• testis
• epididymis
• scrotum
• sperm duct
• seminal vesicle
• prostate gland
• cowper’s gland
• urethra
• penis

Question 4

functions of testis (singular) + location?

Answer 4

• produce sperms
• produce male sex hormones: testosterone
• located in scrotum, connected to epididymis

Question 5

example + function of male sex hormone?

Answer 5

• testosterone
• responsible for the development and maintenance of secondary sexual characteristics in males

Question 6

functions of scrotum?

Answer 6

• pouch-like sacs in between thighs where testes are located
• outside the main body cavity so it is lower temp than body. sperms can only develop at a temp lower than that of the body

Question 7

functions of sperm duct?

Answer 7

• loops over ureter and opens into urethra (for pee to come out)
• sperms from testes travel through the sperm duct to be ejaculated out of the urethra

Question 8

functions of seminal vesicle (gland)?

Answer 8

• opens into sperm duct (sperm duct then seminal vesicle)
• stores sperms temporarily before they are released though the urethra

Question 9

what are the 4 glands in the male reproductive system?

Answer 9

1. seminal vesicle
2. prostate gland
3. cowper’s gland

Question 10

location of prostate gland + cowper’s gland?

Answer 10

• below urinary bladder where the two sperm ducts join the urethra
• beneath the prostate gland is the cowper’s gland

Question 11

functions of all 3 glands?

Answer 11

• secrete a slippery fluid which mixes with the sperms
• fluid contains enzymes and nutrients which nourish the sperms and activate them (stimulate them to swim actively)
• fluid + sperms = semen

Question 12

what is semen?

Answer 12

a slippery fluid containing nutrients and enzymes mixed with sperms
95%—fluid
5%—sperms

Question 13

what do the seminal vesicles produce?

Answer 13

• slightly alkaline mucoid secretions which contain large amounts of fructose + small amounts of vitamins and amino acids (help to nourish and protect the sperm)

Question 14

what does the prostate gland secrete?

Answer 14

• a thin milky alkaline fluid that helps neutralise the acidic secretions in the vagina
• raises conditions in vagina from pH3.5–pH6, sperm becomes increasingly mobile

Question 15

what does the cowper’s gland secrete?

Answer 15

• alkaline secretions
• neutralise any traces of acidic urine in the urethra (male) and serves as lubricant for penis

Question 16

functions of urethra?

Answer 16

• tube that passes from urinary bladder to penis
• both semen and pee pass through the urethra but NOT at the same time due to the sphincter muscle
• sphincter muscle can be controlled to prevent urine from coming out of the bladder during ejaculation

Question 17

functions of penis?

Answer 17

• tissue in penis has numerous spaces that can be filled with blood to become erect and hard
• and erectile organ (contains erectile tissue)

Question 18

what is the sperm made out of?

Answer 18

• acrosome
• cytoplasm
• nucleus
• cell surface membrane
• mitochondria

Question 19

head of sperm?

Answer 19

• 2.5μm wide
• contains: large nucleus and small amount of cytoplasm
• nucleus carries haploid set of chromosomes (23)
• acrosome: contains enzymes that break down part of the egg membranes so that the sperm can penetrate the egg during fertilisation

Question 20

middle piece of sperm?

Answer 20

• contains numerous mitochondria
• mitochondria provides energy for the sperm to swim to the egg

Question 21

tail of sperm?

Answer 21

• beating movement of tail enables sperm to swim towards the egg
• sperm is motile because it can move on its own