Gametogenesis Flashcards
Define gametogenesis
Formation of gametes through meiosis
Cells which divide and differentiate into spermatocytes
Spermatogonia
What process do spermatocytes undergo to form 4 spermatids?
Meiosis
Are spermatids haploid or diploid?
Haploid
What do spermatids become once they mature?
Sperm cells
The head of the sperm cell contains…
The nucleus and acrosome
How many autosomes are contained in a human sperm cell nucleus?
22 + 1 sex chromosome
Function of the acrosome
Produces enzymes that allow sperm to penetrate the surface of the egg
Three main parts of a sperm cell
Head
Mid-peace
Tail
Function of the mid-piece of a sperm cell
Full of mitochondria that provide ATP to power the sperm cell
Function of the tail of a sperm cell
Long flagellum that moves in a whiplike motion to propel sperm forward in fluid
The cell which become primary oocytes
Oogonium
Cells which partially undergo meiosis 1 while female is an embryo
Primary oocytes
When will a primary oocyte complete meiosis 1?
Only if it going to be released during ovulation
Diploid cells in the ovary undergo mitosis (under influence of FSH) to form…
numerous follicles
Which cell inside a follicle enlarges and undergoes meiosis?
The primary oocyte
What is formed when a primary oocyte completes meiosis 1?
A secondary oocyte
When will a secondary oocyte complete meiosis 2?
Only if a sperm cell fertilises the egg
Once a secondary oocyte has completed meiosis 1 it becomes…
an ovum
Differences in meiosis in spermatogenesis and oogenesis
Spermatogenesis: 4 sperm cells produced Oogenesis: 1 ovum produced Unequal meiotic divisions - polar bodies produced which disintegrate
How many autosomes are found in the nucleus of the ovum
22 + 1 X-chromosome
Function of the cytoplasm/yolk of the ovum
Reserve of nutrients for initial stages of zygote development
Membrane which contains the cytoplasm in the ovum
Plasma membrane
Second membrane surrounding the ovum
Yolk/vitelline membrane
Function of the yolk membrane
Becomes impenetrable after fertilisation
The jelly layer surrounding the yolk membrane
Zona pellucida
Function of the zona pellucida
Protects ovum/early zygote
Outermost layer of the ovum
Corona radiata
Structure and function of the corona radiata
Consists of follicle cells that originally surrounded the secondary oocyte
dissolved by acrosome enzymes
