Classical Genetics 2

Question 1

What is Hayfick’s limit?

Answer 1

Point where cells stop dividing.

Question 2

What is the significance of prophase 1 during meiosis?

Answer 2

Crossing over during prophase I allows reshuffling of alleles

Question 3

Describe the stages of meiosis 1:

Answer 3

Interphase - DNA replication produces sister chromatids
Prophase - pairing of homologous chromosomes and crossing over
Metaphase - spindle forms, random alignment of tetrad (4 chromatids)
Anaphase - segregation of homologous chromosomes
Telophase - cytoplasmic cleavage and cell division

Question 4

Describe the stages of meiosis 2:

Answer 4

Prophase II - centrosomes replicate, spindle forms
Metaphase II - chromosomes line up at metaplate
Anaphase II - sister chromatids separate and begin move to opposite sides of cell
Telophase II and cytokinesis - sister chromatids at opposite sides of cell and cell divides