1 A diploid organism has a 2n8 how many individual chromosom

1) A diploid organism has a 2n=8, how many individual chromosomal structures will align on the metaphase plate during each of the following stages: Briefly describe each structure.

A. Mitosis

B. Meiosis I

C. Meiosis II

2. Indicate how many genetically different sperm each of the following males could produce? All alleles are independently assorting.

A. AA Bb Cc DD

B. Aa Bb Cc Dd

Solution

1. Metaphase is the second phase of cell cycle in between the prophase and anaphase, during which the chromosome gets attached to the spindle fibres and they align theselves in the centre of the cell.

a. Mitosis: Mitosis is the division of all the chromosomes. In this 8 chromosomes will align at the metaphase plate.

b. Meiosis I: Meiosis I is similar to mitosis except the chromosomes are not all identical (homologous recombination). So, 8 chromosomes will align at metaphase plate.

c. Meiosis II: It is second divsion after meiosis I, where the egg and sperm cells are formed and they have only 1n of the DNA. So, 4 chromosomes will align at the metaphase plate.

2. AA Bb Cc DD: It will produce 4 diferent gametes which are ABCD,ABcD, AbCD,AbcD.

AaBbCcDd: It will produce 10 different gametes.