S1_L1: Gametogenesis Flashcards
In gametogenesis for females, the result is the formation of?
Ova
In gametogenesis for males, the result is the formation of?
Spermatozoa
TRUE OR FALSE: Human primordial germ cells appear in the wall of the yolk sac at the 3rd week of development and migrate towards the gonads at the 4th to 5th weeks of development.
True
Gametogenesis in females is referred to as?
Oogenesis
Gametogenesis in males is referred to as?
Spermatogenesis
Cell division that produces two daughter cells with the same genetic component as the parent
Mitosis
Mature male and female cells are descendants from?
Primordial germ cells
The process when a haploid cell (n) is
formed from a diploid cell (2n) through meiosis and cell differentiation.
Gametogenesis
Enumerate the purposes of mitosis
- For growth
- To replace worn out cells
This process is known as the reduction division because it results in cells that have half the number of chromosomes
Meiosis 1
This process is referred to as equational division because it does not reduce the chromosome number in the daughter cell.
Meiosis 2
Determine the corresponding descriptions of the stages of Mitosis
- Cell-like features reappear such as the reformation of two nuclei
- Nuclear membrane breaks down allowing the spindle fibers to
attach to the chromosomes at the side called kinetochore - Spindle fibers contract breaking the chromatids at the centromere and moving opposite poles
- Chromosomes align at the metaphase plate (equatorial plane) with kinetochores
attached - Division of the cytoplasm to form two new
cells
A. Prophase
B. Prometaphase
C. Metaphase
D. Anaphase
E. Telophase
F. Cytokinesis
- E
- B
- D
- C
- F
Determine the corresponding descriptions of the stages of Mitosis
- Begins between anaphase and telophase, but
finishes until after telophase - Chromosomes continue to condense and become distinguishable
- Cells elongate and is nearly finish dividing
- Centrosomes have finished moving and are located opposite
each ends of cells - Each chromosome is made of 2 genetically identical
chromatin jointed by a centromere - Sister chromatids now called chromosomes are pulled toward
opposite poles
A. Prophase
B. Prometaphase
C. Metaphase
D. Anaphase
E. Telophase
F. Cytokinesis
- F
- B
- E
- C
- A
- D
Determine the corresponding descriptions of the stages of Mitosis
- Kinetochores
appear at the centromeres - Centrosomes move to opposite directions
- Chromosomes arrive at opposite poles and begin to decondense, uncoil and lengthen; mitotic spindle
breaks - Nucleolus disappears
- Each daughter cell receives half of all doubled chromosome material (same number of chromosomes as mother cell)
A. Prophase
B. Prometaphase
C. Metaphase
D. Anaphase
E. Telophase
F. Cytokinesis
- B
- A
- E
- A
- E
Differentiate mitosis and meiosis
- Necessary for
growth (cellular proliferation) and repair - Crossing over takes place
- Type of cell division that takes
place in somatic cells - Starts with a single parent cell
- 4 haploid daughter cells are formed
- Number of chromosomes
remain diploid in daughter
cells
A. Mitosis
B. Meiosis
C. Both
D. Neither
- A
- B
- A
- C
- B
- A
Differentiate mitosis and meiosis
- Crossing over does not take
place - Necessary for
sexual reproduction - Type of division takes place in gametic (germ) cells
- 2 diploid daughter cells are formed
- Number of chromosomes
becomes haploid in
daughter cells - Genetic variation increases
A. Mitosis
B. Meiosis
C. Both
D. Neither
- A
- B
- B
- A
- B
- B
TRUE OR FALSE: By the 5th month of gestation, majority of the oogonia have
degenerated except those in the surface.
False, it’s 7th month
TRUE OR FALSE: A newborn baby girl has about two million primary
oocytes.
True
TRUE OR FALSE: No new primary oocytes will be produced during a
female’s life.
True
At most, how many oocytes will be released during a woman’s reproductive years?
400-500
TRUE OR FALSE: Oogonia become primary oocytes (diploid cells). Primary oocytes begin the process of meiosis, but
are halted in prometaphase I.
False, it’s prophase I.
Additional: Singular of oogonia is oogonium
TRUE OR FALSE: In females, beginning at puberty, and continuing every
month thereafter, two follicles will begin growing in the ovary.
False, only one follicle
Fourteen days after the beginning of the follicle’s growth, and just before leaving the ovary, the primary oocyte will finish its first meiotic division and become a
secondary oocyte.
This process is stimulated by what hormone?
follicle stimulating
hormone (FSH)
TRUE OR FALSE: Polar bodies formed in the process of oogenesis will eventually degenerate.
True
What induces the secondary oocyte to go through its second meiotic division?
Penetration of the sperm
Additional: The 2nd meiotic division also occurs with unequal cytokinesis.
TRUE OR FALSE: The secondary oocyte will be released from the ovary during ovulation without becoming an ovum (egg) yet.
True
TRUE OR FALSE: In the process of the 1st meiotic division in oogenesis, equal cytokinesis occurs and meiosis stops again.
False, it’s unequal
This results in a large haploid cell that will eventually become the egg (ovum) and a small haploid cell that becomes a polar body.
Oogenesis terminates with the occurrence of ___.
Menopause
The sperm is larger than the spermatocyes. The ova is smaller than the oocytes.
A. Only the 1st statement is true
B. Only the 2nd statement is true
C. Both statements are true
D. Both statements are false
D. Both statements are false
Sperm is smaller
Ova is larger
The final product of spermiogenesis is a ___ mature spermatozoon.
non-motile
Note: Since it is not yet motile, the spermatozoa produced will still be sterile.
Determine the corresponding descriptions of the phases of spermiogenesis
- Elongation
of microtubules on one of the centrioles of the
spermatid - Genetic material (DNA)
undergoes packaging as protamines - Golgi apparatus surrounds
the anterior of the spermatid to form the
acrosome - The residual cytoplasm has been disposed
of - Intensified activity of the Golgi apparatus
A. Golgi phase
B. Cap phase
C. Tail phase
D. Maturation phase
- C
- A
- B
- D
- A
The spermatozoa become motile cells when they further develop in the ___.
epididymis
The migration of the spermatozoon from the seminiferous tubules to the epididymis to become a motile sperm cell
Spermiation
Determine the corresponding descriptions of gametogenesis in males and females
- Produces 1 gamete with 2-3 polar bodies
- Begins at puberty
- Cells are equally divided in meiosis
- Germ line epithelium is not involved in gamete production
- Duration is in arrested stages
- Begins in the fetus (pre-natal)
A. Spermatogenesis
B. Oogenesis
- B
- A
- A
- B
- B
- B
Determine the corresponding descriptions of gametogenesis in males and females
- Occurs entirely in the testes
- Lifelong process but production reduces with age
- Cytoplasm is unequally divided in meiosis
- Release is monthly from puberty
- Produces 4 gametes
- An uninterrupted process with a continuous release
A. Spermatogenesis
B. Oogenesis
- A
- A
- B
- B
- A
- A
TRUE OR FALSE: Oogenesis occurs mostly in the ovaries.
True
TRUE OR FALSE: In spermatogenesis, germ line epithelium is not involved in gamete production.
False, it is involved
The most common trisomy that results in Down syndrome, which is characterized by dysmorphic features of a small head and flat face, and cardiovascular problems.
Trisomy 21
-Extra chromosome 21
Edward’s Syndrome, which is characterized by severe mental disability, clenched hands, a large back of the head, a small mouth, and a rocker bottom foot, is a result of what trisomy?
Trisomy 18
Patau Syndrome, which is characterized by severe mental disability, a clenched hand, a large back of the head, a small mouth, and a rocker bottom foot, is a result of what trisomy?
Trisomy 13
A condition present in males with 47 chromosomes and an XXY karyotype.
It is characterized by sterility, testicular atrophy, hyalinization of the seminiferous tubules, and gynecomastia.
Klinefelter Syndrome