Human Reproduction Gametogensis

Question 1

What is spermatogenesis and when can it occur

Answer 1

In testis the immature male germ cell (spermatogonia) produce sperms by spermatogenesis that begins at puberty

Question 2

How does spermatogonia multiply

Answer 2

The spermatogonia present on the inside wall of the seminiferous tubules undergoes mitotic division and increases in number

Question 3

Spermatogonium ploidy and chromosome no

Answer 3

Each spermatogonium is diploid in nature and has 46 chromosomes

Question 4

Define 1° spermatocytes

Answer 4

Some of the spermatogonia called primary spermatocytes periodically undergo meiosis

Question 5

What is spermiogenesis

Answer 5

The spermatids are transformed into spermatozoa (sperms) by the process called spermiogenesis

Question 6

What happens after spermiogenesis

Answer 6

The sperm heads become embedded in the sertoli cells and are finally released from the seminiferous tubules by the process called spermiation

Question 7

What hormones is the primary cause of spermatogenesis

Answer 7

Spermatogenesis starts at the age of puberty due to significant rise in the gonadotropin releasing hormone (GnRH) which is a hypothalamic hormone

Question 8

Who relases the GnRH hormone

Answer 8

The hypothalamus

Question 9

Who does GnRH act as
What does that do

Answer 9

The increased levels of GnRH then acts as the anterior pituitary gland and stimulates secretion of two gonadotropins
Luetenising hormone (LH)
Follicle stimulating hormone (FSH)

Question 10

How does LH work and what does it do

Answer 10

LH acts as the leydig cells and stimulates synthesis and secretion of androgens
androgens in turn stimulate the process of spermatogenesis

Question 11

Who does FSH work as what does it do

Answer 11

FSH acts as the sertoli cells and helps in the secretion of some Factors that help innthe process of spermatogenesis

Question 12

Parts of the sperm

Answer 12

Microscopic structure composed of head neck middle piece and a tail

Question 13

First outer layer of sperm

Answer 13

A plasma membrane envelops the whole body of the sperm

Question 14

Constituents of sperm head

Answer 14

The sperm heads contains an elongated haploid nucleus the anterior portion of which is covered by a cap like structure called acrosome

Question 15

What is the acrosome
What is it made of and it’s function

Answer 15

The cap like structure is called the acrosome which is filed with enzymes that help in fertilisation of ovum

Question 16

Middle piece constituents and functions

Answer 16

The middle piece contains numerous mitochondria which produce energy for the movement of the tail that facilitate sperm motility essential for fertilisation

Question 17

How many sperms released during coitus

Answer 17

The human male ejaculates about 200-300 million sperms during coitus out of which 60 percent have normal shape and size and out of those 40 percent show vigorous motility

Question 18

Which secretion help in sperm motility

Answer 18

Secretion of epididymis vas deferens seminal vesicle and prostate are essential for maturation and motility of sperm

Question 19

Semen constituents

Answer 19

The seminal plasma along with the sperms constitute the semen

Question 20

Who maintains the function of the male accessory ducts and glands

Answer 20

Androgens

Question 21

What is oogenesis

Answer 21

Oogenesis is the formation of mature female gamete

Question 22

When does oogenesis start
Why is it initiated
How many oogenesis formed in each fetal Ovary
What is oogonia

Answer 22

Oogenesis is initiated during the embryonic development stage when a couple of million gamete mother cells (oogonia) are formed within each fetal Ovary no more oogenia are formed or added after birth

Question 23

Primary oocyte stuck stage

Answer 23

When female egg cells enter into prophase 1 of the meiotic division and get temporarily arrested at that stage called primary oocyte

Question 24

What is primary follicle

Answer 24

Each primary oocyte gets surrounded by a layer of granuloma cells and is called the primary follicle

Question 25

Degeneration period of follicles

Answer 25

A large number of follicles degenerate from the period of birth to puberty therefore at puberty only 60000 to 80000 follicles are left at each Ovary

Question 26

What happens to follicles during puberty

Answer 26

Therimary follicles get surrounded by more layers of granulosa cells and a new thecal and are called Secondary follicles

Question 27

Tertiary follicle and speciality

Answer 27

The Secondary follicle soon transforms into tertiary follicle which is characterized by a fluid filled cavity called antrum

Question 28

Parts of the theca layer

Answer 28

Inner theca layer
Outer theca layer

Question 29

Cytoplasm division ratio between polar body and Secondary oocyte

Answer 29

Secondary oocyte retains bulk of the nutrient rich cytoplasm of the primary oocyte

Question 30

Final follicle stage

Answer 30

The tertiary follicle further changes into the mature follicle or graafian follicle

Question 31

When is Zona pallucida formed what is it

Answer 31

The Secondary oocyte forms a new membrane called Zona pellucida surrounding it

Question 32

What is ovulation

Answer 32

The graafian follicle ruptures to release the Secondary oocyte from the Ovary by the process called ovulation