Question

Number of bivalents, centromeres, DNA strands for 20 chromosomes are​

Answer 1

Answer:

Maize has chromosome number is 20(2n).

In pachytene stage, a tetrad of the chromosomes has formed known as a bivalent. This is the stage when homologous recombination, including chromosomal crossover, occurs. The DNA molecule is packaged into thread-like structures called chromosomes. A bivalent sometimes referred to as a tetrad, is the association of a pair of homologous chromosomes physically held together by at least one DNA crossover. This physical attachment allows for alignment and segregation of the homologous chromosomes in the first meiotic division. Telomeres are the caps at the end of each strand of DNA that protect our chromosomes, like the plastic tips at the end of shoelaces.

So, in maize, the number of bivalent and tetrad is 20,

Each chromatid has 1 DNA so in 40 chromatids DNA is 20*2=40,

Each DNA has 2 telomers so Telomeres is 40*2=80

Correct answer is “20,20,40,80”.

Answer 2

Answer:

Maize has chromosome number is 20(2n).

In pachytene stage, a tetrad of the chromosomes has formed known as a bivalent. This is the stage when homologous recombination, including chromosomal crossover, occurs. The DNA molecule is packaged into thread-like structures called chromosomes. A bivalent sometimes referred to as a tetrad, is the association of a pair of homologous chromosomes physically held together by at least one DNA crossover. This physical attachment allows for alignment and segregation of the homologous chromosomes in the first meiotic division. Telomeres are the caps at the end of each strand of DNA that protect our chromosomes, like the plastic tips at the end of shoelaces.

So, in maize, the number of bivalent and tetrad is 20,

Each chromatid has 1 DNA so in 40 chromatids DNA is 20*2=40,

Each DNA has 2 telomers so Telomeres is 40*2=80

Correct answer is “20,20,40,80”.