Reproduction Flashcards
(95 cards)
Autosomal cells
2n
Germ cells
n
Cell cycle
G1 = cellular content are duplicated S = chromosomes are duplicated G2 = Quality control checks Mitosis G0 = cell cycle arrest
Mitosis
Prophase Metaphase Anaphase Telophase Cytokinesis
Prophase
- chromatin condenses to chromosomes;
- centriole pairs separate to opposite poles,
asters –> centriole –> microtubules –> chromosomes at the centromere via a kinetochore complex - nuclear envelope dissolves
Metaphase
chromosomes are aligned at metaphase plate, equidistant between the 2 centriole poles.
Anaphase
centromeres split and sister chromatids separate (in humans, 46 on each side) to opposite poles by shortening of kinetochore fibers
Telophase
spindle apparatus disappears; 2 nuclear membranes reform; chromosomes uncoil to chromatin
Cytokinesis
microfilaments (actin) form the cleavage furrow in a ring; actin filaments contract; pinches off connection between the two daughter cells
Control of cell cycle
- restriction checkpoints betwen G1/S and G2/M to check for any DNA damage to repair
- Cyclins and cyclin-dependent kinases, when activated, they phosphorylate TF
Meiosis 1: Reductional division
prophase 1: tetrads
metaphase 1: chromosomes are aligned at metaphase plate, equidistant between the 2 centriole poles.
anaphase 1: each chromosome is on opposite side by the centrioles
Telophase 1: two cells with one chromosome each
Linkage
tendency of genes to be inherited together
Meiosis 2: equational division
Similar to Mitosis (sister chromatids split off and separate into 4 cells of 1n
X chromosome disorders
men will always express X chromosome disorders because hemizygous
What components are needed for male reproduction?
AMT, DHT, Testosterone from Leydig cells
What is the role of AMH
The Mullerian duct will regress and no uterus nor oviduct will be formed
What is the role of T in relations to the Wolffian duct?
it will be maintained and developped to become the epididymis/vas
What is SRY responsible for?
the development of Testes
What cells secrete AMH
Sertoli cells
What is the sequence of spermatogenesis?
primordial germ cells –> spermatogonium (2n) –> primary spermatocyte (2n) –> secondary spermatocyte (n)–> spermatids (n)
From the basement membrane to the lumen of Seminiferous tubule
Spermatogenesis
the formation of sperm cells
Spermiogenesis
maturation of spermatids into sperm cells, unecessary cytoplasm is shed off
Acrosome
a modified Golgi apparatus, contains enzymes that penetrate the corona radiata and zona pellucida of the ovum, permitting fertilization.
LH act on which cell?
on testes on Leydig cells to produce Testosterone