Question

Name the following :
(i) The condition in which a cell has the normal paired chromosomes.
(ii) The condition in which a cell contains only one member of each pair of
chromosomes.
(iii) The pairing of maternal and paternal chromosomes during meiosis.
(v) The exchange of parts in homologous (maternal and paternal) chromosomes
during prophase-I of meiosis.
(vi) The point by which a chromosome is attached to the spindle fibre.
(vii) The type of cell division that results in growth.

Answer 1

Answer:

3-synapsis

6-centromere

7-mitosis

Answer 2

Answer:

(i) Diploid cells.

(ii) Haploid cells.

(iii) Synapsis.

(v) Crossing over.

(vi) Centromeres.

(vii) Mitosis.

Explanation:

(i) A diploid cells have two chromosomes sets. It is denoted as ‘2n’. Each set is a set of single homologues chromosome. In diploid, two chromosomes are from mother and another two chromosomes are from father.

(ii) A haploid cells have single chromosome set. The haploid also refers the number of chromosomes in a cell.

(iii) Synapsis occurs during beginning of meiosis which is prophase I where chromosomal crossover takes place.

(iv) During crossover, the mixture of parental characteristic is found in the offspring which occurs during sexual reproduction.

(v) The spindle fiber and centromere are attached via kinetochore. Centromere plays a major role in chromosomal segregation.

(vi) Mitosis is a process of replication of chromosomes to form another cell. In this the mother cell is divided into cell daughter cell.