Biology - Study Mode
[#571] It is the site of chromosome attachment to the fibres of spindle.
Correct Answer
(B) Centromere
Explanation
Solution: The centromere is the part of a chromosome where the sister chromatids are linked together during the cell division. In mitosis, spindle fibres attach to the centromere via the kinetochore. Centromeres were first defined as genetic loci that direct the behaviour of chromosomes.
[#572] During which phase centromeres divide and chromatids separate into chromosomes?
Correct Answer
(D) Anaphase
Explanation
Solution: During anaphase, the “upward phase,” the cohesin proteins degrade, and the sister chromatids separate at the centromere. Each chromatid, now called a chromosome, is pulled rapidly toward the centrosome to which its microtubule is attached.
[#573] The shape of chromosome is clearly visible at
Correct Answer
(C) Metaphase
Explanation
Solution: The shape of chromosome is clearly visible at metaphase.
[#574] How many daughter cells are formed after the completion mitosis?
Correct Answer
(A) 2
Explanation
Solution: At the end of mitosis, two daughter cells will be formed which are exact copies of the original cell. Each daughter cell will have 30 chromosomes.
[#575] Pollen is produced by the process of
Correct Answer
(A) Mitosis
Explanation
Solution: Pollen development is a postmeiotic process that produces immature pollen grains from microspores. The maturation process can be dissected into various stages. During microspore mitosis, the pollen first develops a large vacuole that mediates nuclear migration to produce polarized cells.