Chapter 13 (meiosis)

Question 1

Formation of Sperm

Answer 1

Meiosis part
1)Mitosis is required for the precursor (spermatocyte - primary)
2)After meiosis 1, 2 daughter cells are created (spermatocytes- secondary), but they have too much genetic information (they have sister chromatids)
3)Sister chromatids separate and this results in 4 cells (spermatids) [meiosis II]

After meiosis (cell differentiation)
Mitochondria concentrated so sperm have atp to swim

Question 2

Formation of Egg cells in females

Answer 2

meiosis part
1)Mitosis is required for the precursor (oocyte)
2)After meiosis 1, 2 daughter cells are created (oocyte-secondary), there is an unequal distribution of cytoplasmic contents within them (nutrient prioritization for only one of the cells)
3)Sister chromatids separate into more polar bodies that are not viable on their own

Question 3

Phases of Prophase I and what happens within them

Answer 3

Leptotene
-Initiation of condensing chromatin fibers
-Components of synaptonemal complex are created

Zygotene
-Synaptonemal complex starts forming (synapsis). Complex formed from two diads to make a tetrad This is how homologous chromosomes start to interact with each other. This closer proximity is important for exchange
-Further condensation

Pachytene
-Crossing over happens (exchange of genetic info between homologous chromosomes)
-Further compaction
-Synaptonemal complex involves entire length of the chromosome

Diplotene
-Tetrad complex falls apart
-Chiasma (area where pairs are still connected) is visible

Diakinesis
-Diads move further apart
-No more synaptonemal complex
-Only thing visible is attachment between homologues