Answer:
Microtubules have shapes like a spindle and are arranged to form centrosome and a cluster of such microtubules form centriole.
Explanation:
Microtubules are seen in eukaryotic cells to give shape and structure to the cells and they form part of the cytoskeleton. They are known to grow long and are dynamic. Centrosomes are known to be main microtubule that are found in animal cells. They are organelles that are made from the arrangement of clusters of microtubules. The centrioles are organized microtubules that actually help to serve as skeletal system of the cell. These centrioles help to determine the locations of the nucleus.
Answer:
number 1 its 25 number 2 its 10000
Explanation:
Answer: a. Genetic recombination (crossing over)
b. Can also be explained in terms of crossing over
c. Non disjunction of homologous chromosomes in meiosis 1
Explanation:
The process that allows for the transfer of both the paternal and maternal materials to is the crossing over process that takes at meiosis 1 changing them to secondary spermatocytes. While they are still primary spermatocytes, they are still diploid cells having both the maternal and paternal chromosomes. But since the spermatozoon is an haploid cell, it is able to retail some of both parents chromosome by the crossing over event which takes place between homologous paternal and maternal chromosomes allowing them to exchange materials. Thus the chromosomal contents of the primary spermatocyte differs from that of the spermatozoon.
C. This can occur as a result of the one of the homologous chromosome pair refusing to separate at meiosis 1 with one gamete containing 4 chromosomes/8 sister chromatids and the second having 2 chromosomes/4 sister chromatids.
