Chapter 12 Animal reproduction and development

Question 0

Leydig cells

Answer 0

clusters of cells located between seminiferous tubules that produce testosterone

Question 1

Epididumis

Answer 1

tube in the testes where sperm gain motility

Question 2

prostate gland

Answer 2

large gland that secretes semen directly into the urethra

Question 3

Srotum

Answer 3

Sac outside the abdominal cavity that holds the testes.

has a cooler temperature which enables sperm to survive

Question 4

Seminal vesicles

Answer 4

secrete muscus, fructose sugar, and prostagladin

Question 5

Prostaglandin

Answer 5

hormone that stimulates uterine contractions during sex

Question 6

Seminiferous tubules

Answer 6

site of sperm formation in the testes

Question 7

Sertoli cells

Answer 7

provides nutrients for developing sperm

Question 8

Testes

Answer 8

male gonads where sperm are produced

Question 9

Urethra

Answer 9

tube that carries semen and urine

Question 10

vas deferens

Answer 10

muscular duct that carries sperm during ejaculation from the epididymis to the urethra in the penis

Question 11

Fallopian tubes (or oviducts)

Answer 11

where fertilization occurs

Question 12

Uterus

Answer 12

Where the blastocyst is implanted and the embryo will develop during a 9 month gestation

Question 13

Endometrium

Answer 13

lining of the uterus that thickens monthly in preparation for implantation of the blastocyst

Question 14

vagina

Answer 14

the birth canal

Question 15

Menstrual cycle of the human female

Answer 15

Includes: follicular phase, ovulation, luteal phase, menstruation

Question 16

Follicular phase

Answer 16

several follicles in the ovaries grow and secrete increasing amounts of estrogen in response to follicle stimulating hormone (FSH) from the anterior pituitary

Question 17

Ovulation

Answer 17

The secondary oocyte ruptures out of the ovaries in response to luteinizing hormone

Question 18

Luteal phase

Answer 18

the corpus luteum forms in response to luteinizing hormones. it is the follicle left behind after ovulation and secretes estrogen and progesterone, which thcikens the endometrium of the uterus

Question 19

Menstruation

Answer 19

Monthly shedding of the lining of the uterus when implantation of an embryo does not occur

Question 20

Spermatogenesis

Answer 20

process of sperm production

continuous process that starts at puberty

Question 21

Lutenizing hormone

Answer 21

induces the interstitial cells of the testes to produce testosterone

Question 22

Follicle stimulation hormone

Answer 22

together with LH, testosterone induces maturation of the semiferous tubules and stimulates the beginning of sperm prodution

Question 23

Process of spermatogenesis

Answer 23

The spermatogonium cells (2n) divides by MITOSIS to product 2 primary spermatocytes (2n). Then they undergo MEOSIS 1 to produce 2 secondary spermatocytes (n). Then they undergo MEOSIS 2 and yields 4 spermatids (n).

the spermatids move to the epididymis where they become motile

Question 24

Oogenesis

Answer 24

the production of ova which begins prior to birth

Question 25

Process of oogenesis

Answer 25

an oogonium cell (2n) undergoes mitosis to produce primary oocytes (2n). These remain in the small follicles in the ovary until puberty,

FSH stimulates the follicles to complete meiosis 1 which makes secondary oocytes (n) which is released at ovulation,

MEOSIS2 stops again and does not continue until fertilization when a sperm penetrate the secondary oocyte.

this is a START-STOP process

Question 26

Fertilization

Answer 26

fusion of sperm and ovum nuclei.

Begins with acrosome reaction, the head of the sperm (acrosome) releases hydrolytic enzymes to penetrate through the jelly coat of the egg. Specific molecules of the sperm binds to receptor molecules which ensure that the egg will be fertilized by the same species.

Once sperm binds the egg depolarizes so that no other sperm can penetrate egg (fast block to polyspermy)
Converting the vitelline membrane into an impenetrable fertilation envelope (slow block to polyspermy)

Question 27

Parthenogenesis

Answer 27

development of an unfertilized egg

can be activated artificially by electrical stimulation or by injection with ca++

Question 28

Embryonic development

Answer 28

has 3 stages: cleavage, gastrulation, and organogenesis