Spermatogenesis

Gametogenesis (Spermatogenesis and Oogenesis)

By Anna Masriyani

Human reproductive system (2)

Before we start, let's play a game

Multiple Choice

A person who says one thing and then does something different is ___.

• direct

• manipulative

• hypocritical

• straight

Multiple Choice

A person who is good at making other people do what they want is ___.

• original

• dishonest

• truthful

• manipulative

Multiple Choice

A person who doesn't keep secrets from you is ___.

• biased

• direct

• open

• fake

Multiple Choice

A person who has strong beliefs about what is morally correct is ___.

• fake

• unethical

• ethical

• straight

Multiple Choice

A person who behaves in a dishonest or indirect way is ___.

• trustworthy

• hypocritical

• open

• devious

Multiple Choice

Don't ___! You can't have walked 100 km!

• fool

• exaggerate

• cheat

• tell

Multiple Choice

I ___ that I didn't take your watch. It wasn't me!

• disguise

• tell

• swear

• own up

Multiple Choice

Mary's story didn't ___ me. I knew she was lying.

• fool

• cheat

• disguise

• fabricate

Multiple Choice

That picture can't be real. Did you ___ it?

• disguise

• reveal

• photoshop

• fabricate

Multiple Choice

Tom couldn't ___ the fact that he'd been crying.

• manipulate

• disguise

• exaggerate

• mislead

Multiple Choice

___ a fib / a lie / the truth

• say

• tell

• utter

• make

Multiple Choice

Someone who tricks others to get what they want is ___.

• hypocritical

• devious

• dishonest

• unethical

Did you remember, what kind of cell division in sperm or ova production?

Is it mitosis or meiosis?​

Now we can start the lesson

GAMETOGENESIS​

Gametogenesis is the process of forming gametes. In humans, gametogenesis is divided into two, namely spermatogenesis and oogenesis. Where spermatogenesis is the process of formation of male gametes (spermatozoa), while oogenesis is the process of formation of female gametes (ova).

Spermatogenesis occurs in the testes, specifically in the seminiferous tubules. It is initiated by spermatozoa stem cells called spermatogonia. Each human spermatogonia contains 46 chromosomes or is diploid (2n). Spermatogonia will perform mitotic division to produce primary spermatocytes which also have 46 chromosomes (2n).

Spermatogenesis

Primary spermatocytes undergo meiosis I division and produce 2 secondary permatocytes, each of which has 23 chromosomes or is gaploid (n). Each secondary spermatocyte divides by meiosis II and produces 2 spermatids (n). Spermatids differentiate into functional spermatozoa through a process called spermiogenesis.

Spermatogenesis

Sperms that are mature and functional are motile because they are equipped with microtubules. Spermatozoa consist of several parts, namely the head, the middle (mid piece), and the tail.

Spermatogenesis

Head Section

​

The head of the sperm contains the nucleus and acrosome. The acrosome is located at the front of the sperm head. The sperm acrosome produces the hormone hyaluronidase and proteinase which functions to help sperm penetrate the egg cell layer.

​

​

Spermatogenesis

​

Middle part

​

The middle part (mid piece) contains mitochondria which function to produce energy which is used to support sperm movement.

​

Spermatogenesis

Tail Part

​

​

The tail of the sperm serves to support the movement of sperm when it will fertilize an egg.

Spermatogenesis

A man can start producing sperm when his testes have produced the hormone testosterone. This happens during puberty. In addition to functioning to trigger the formation of sperm, the hormone testosterone also functions to regulate secondary sex characteristics in men such as the growth of a mustache, hair in the armpits and around the genitals, more muscular muscles, and a louder voice.

Spermatogenesis

Although enormous sperms will be going to combine with egg but there is only one sperm can fertilize successfully. Then chromosome inside that sperm will match with X chromosome of female’s egg in order to determine the gender of the child.

Spermatogenesis

Sperm contains X chromosome:

​

• Determine female gender of newborn

• Big sizeS

• hort tail

• Slow movement

• Endurable, hard to be killed

Spermatogenesis

Sperm contains Y chromosome:

​

• Determine male gender of newborn

• Small size

• Long tail

• Quick movement

• Fragile, easy to be killed

Spermatogenesis

Now, let's watch a video here:

https://youtu.be/krSMZDsjLuU

Now, please answer this questions

Multiple Choice

Where does Spermatogenesis occur?

• Semiferous tubules 
• Fallopian Tubes
• Vas deferens
• Prostate

Multiple Choice

What type of cells are spermatids?

• diploid
• Haploid 
• somatic
• stem

Multiple Choice

What name is given to mature sperm?

• Spermatocyte

• Spermatozoa

• Spermatogonium

• Spermatogonia

Multiple Choice

What name is given to the cells that attach to Sertoli cells?

• Secondary spermatocytes

• Spermatogonia

• Primary spermatocytes

• Spermatids

Multiple Choice

Where do you find spermatogonia?

• Attached to the germinal epitheliium of the seminiferous tubule

• Attached to the Sertoli cells

• Attached to Leydig cells

• In the epididymis

Multiple Choice

What cells secrete testosterone?

• Sertoli cells

• Spermatocytes

• Spermatids

• Leydig cells

Multiple Choice

Spermatogenesis involves...

• Mitosis only

• Meiosis only

• Mitosis followed by meiosis

Multiple Choice

Are spermatogonia Diploid or haploid?

• Diploid

• Haploid

Multiple Choice

How many secondary spermatocytes are produced after the first round of meiosis?

• 1

• 2

• 4

Multiple Choice

Spermatogenesis occurs in the

• A)epididymis

• B)seminiferous tubules.

• C)prostate gland

• D)vas deferens

• E)seminal vesicle.

Multiple Choice

During spermatogenesis, which of the following cells is the first to become haploid?

• A)primary spermatocyte

• B)secondary spermatocyte

• C)sperm cells

• D)spermatid

• E)spermatogonium

Multiple Choice

Meiosis II of spermatogenesis results in the formation of secondary spermatocytes.

• TRUE

• FALSE

Multiple Choice

A primary spermatocytes.....

• A)divide by mitosis to produce two secondary spermatocytes

• B)divide by meiosis to produce two secondary spermatocytes.

• C)divides by meiosis to produce four spermatids

• D)divides by meiosis to produce two spermatids.

• E)divides by mitosis to produce two spermatids.

Multiple Choice

The primary spermatocytes and the spermatogonia each contain 46 chromosomes.

• True

• False

Multiple Choice

The spermatids and the secondary spermatocytes each contain 23 chromosomes.

• True

• False

Multiple Choice

Which of the following is a correct sequence of cells in spermatogenesis?

• spermatogonium -> secondary spermatocyte -> primary spermatocyte

• primary spermatocyte -> spermatogonium -> secondary spermatocyte

• spermatogonium -> primary spermatocyte -> secondary spermatocyte

• none of the above

Multiple Choice

Sperm is produced by testes in numerous number throughout life from puberty onwards.

• TRUE

• FALSE

Multiple Choice

There are two types of sperms ; sperm with X chromosome and sperm with Y chromosome.

• TRUE

• FALSE

Multiple Choice

Sperm has a large nucleus with small amount of cytoplasm, but ovum has a large cytoplasm with small amount of nucleus.

• TRUE

• FALSE

Multiple Choice

Acrosome is a part of the head of sperm that contains enzymes to penetrate the egg.

• TRUE

• FALSE

Multiple Choice

The tail of sperm is flagellum.

• TRUE

• FALSE

Multiple Choice

The tail of sperm enables them to swim.

• TRUE

• FALSE

Multiple Choice

Testes can produce mature sperm start from birth.

• TRUE

• FALSE

Multiple Choice

Large number of sperm is released per ejaculation.

• TRUE

• FALSE

Okay...

Let's move to another topic​

Oogenesis

Oogenesis occurs in the ovaries. From the embryo, egg stem cells called oogonia develop in the ovaries. Oogonia which have 46 chromosomes or are diplod (2n) undergo mitotic division and produce primary oocytes (2n). When the embryo is 6 months old, the primary oocyte undergoes meiosis I division and stops at the prophase I stage. This primary oocyte stops dividing until the female reaches puberty.

When a woman reaches puberty, the anterior pituitary gland will begin to produce the hormone FSH (Follicle Stimulating Hormone). This hormone functions to trigger the development of follicles in the ovaries. Therefore, the primary oocyte will continue the division of meiosis I and produce 2 cells of different sizes.

Oogenesis

Oogenesis is the process of formation of female gametes. This process begins inside the fetus before birth. The steps in oogenesis up to the production of primary oocytes occur before birth. Primary oocytes do not divide further. They either become secondary oocytes or degenerate.

Oogenesis occurs in the outermost layers of the ovaries. Oogenesis starts with a germ cell called oogonium and undergoes mitosis to increase in number. The process of oogenesis takes place in the following three stages:

• Pre-natal

• Antral

• Pre-ovulatory

Oogenesis

The primary oocyte grows while being arrested in meiosis-I. The follicular cells proliferate and form a stratified cuboidal epithelium. Such cells are known as granulosa cells. These cells secrete glycoproteins to form zona pellucida around the primary oocyte.

Pre-natal Stage

The fluid-filled area, present between granulosa cells, combines to form a central fluid-filled space called the antrum. These are known as secondary follicles. In every month cycle, these secondary follicles develop under the influence of follicle-stimulating hormone and luteinizing hormone.

Antral Stage

This stage is induced by LH surge, and meiosis-I completes here. Two haploid cells of unequal sizes are formed within the follicle. One of the daughter cells that receive less cytoplasm forms a polar body. This cell does not participate in ovum formation. The other daughter cell is known as the secondary oocyte. The two daughter cells undergo meiosis-II. The polar body replicates to form two polar bodies, while the secondary oocyte arrests in the metaphase stage of meiosis-II.

Pre-ovulatory Stage

Oogenesis Stages

Let's watch a video here:

https://youtu.be/2Ksxzw_y7Xw​

Now, answer the questions below

Multiple Choice

Oogenesis results in the formation of:

• 1 ovum; 3 polar bodies
• 2 ova; 2 polar bodies
• 1 ovum; 3 secondary oocytes
• 4 ova

Okay, that's it for today...

Multiple Choice

When does completion of meiosis occur?

• Stage 1

• Stage 2

• Fertilisation

• Ovulation

Multiple Choice

Oogenesis produces 4 eggs per cycle.

• false

• True

Multiple Choice

Which one of the following is not diploid?

• germinal epithelial cell

• oogonia

• primary oocyte

• secondary oocyte

Multiple Choice

The second polar body is only made after fertilisation.

• True

• False

Multiple Select

Which of these organs are part of the female reproductive organs. Select 3 for points

• Falopian tubes

• Ovaries

• Prostate

• Uterus

Multiple Choice

Name letter F

• Ovaries

• Uterus

• Vulva

• Vagina

Multiple Choice

Structure 7 is the 

• cervix
• vagina
• uterus
• ovary

Multiple Choice

When does oogenesis begin?

• at birth

• before birth

• at the onset of adulthood

• at the onset of puberty

Fill in the Blanks

Fill in the Blanks

Multiple Choice

Which one of the following is not diploid?

• germinal epithelial cell

• oogonia

• primary oocyte

• secondary oocyte

Multiple Choice

Which of these cells only exists in the fallopian tube?

• Oogonium

• Primary oocyte

• Secondary oocyte

• Ovum

Multiple Choice

In humans, when are primary oocytes made?

• When the female is still just a fetus.

• During puberty.

• Sometime between birth and the girl's second birthday.

• Throughout a woman's life until menopause.

Multiple Choice

Primary oocyte is arrested at

• Prophase I

• Metaphase I

• Prophase II

• Metaphase II