NEET BIOLOGY

CELL STRUCTURES AND FUNCTION

CELL CYCLE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Two identical copies of a chromosome is
A
centromere
B
centrosome
C
chromatid
D
chromosome
Explanation: 

Detailed explanation-1: -A chromatid is one of the two identical halves of a chromosome that has been replicated in preparation for cell division. The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere.

Detailed explanation-2: -The two copies of a chromosome are called sister chromatids. The sister chromatids are identical to one another and are attached to each other by proteins called cohesins.

Detailed explanation-3: -Before a cell divides to make two cells, it copies all of its chromosomes. These copies, called sister chromatids, are identical. Until the cell divides, the identical copies stay connected with each other by their middles (centromeres.)

Detailed explanation-4: -A sister chromatid refers to the identical copies (chromatids) formed by the DNA replication of a chromosome, with both copies joined together by a common centromere. In other words, a sister chromatid may also be said to be ‘one-half’ of the duplicated chromosome. A pair of sister chromatids is called a dyad.

Detailed explanation-5: -Each daughter cell will have half of the original 46 chromosomes, or 23 chromosomes. Each chromosome consists of 2 sister chromatids. The daughter cells now move in to the third and final phase of meiosis: meiosis II. At the end of meiosis I there are two haploid cells.

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