During prometaphase, the microtubules of the mitotic spindle attach only to the kinetochore of a single sister chromatid and not to the other for the maternal copy of chromosome 21. what will happen to the copy number of chromosome 21 in the resulting daughter cells?

a. one of the daughter cells is missing both copies of chromosome 21 and the other cell has four copies of chromosome 21.

b. both daughter cells have double the normal number of chromosome 21 (four copies each).

c. one of the daughter cells has trisomy (three copies) of chromosome 21 and the other daughter cell is missing one of the two copies of chromosome 21.

humans, along with other animals and plants, have linear chromosomes that are arranged in pairs within the nucleus of the cell. the only human cells that do not contain pairs of chromosomes are reproductive cells, or gametes, which carry just one copy of each chromosome.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).