Question

DNA content has the tendency to double itself during sexual reproduction due to combining of the genetic material from two parents. How can the problem of DNA doubling be solved to maintain the consistency of the genetic material throughout the species? (3 marks)

Answer 1

in order to reproduce DNA replicate or copy itself or double it or divide it to  form new species
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in human there are two basic types of cells 1. Somatic cells 2. germ cells or gametes. the somatic cells are diploid ( i.e. they have two complete set  of chromosomes). and on the other hand germ cells are  haploid( it contains half the number of chromosomes.
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so during copulation germ cells fuses and form zygote in which haploid cells a diploid zygote . i.e male contains  only half i.e 23 chromosome(22 x chromosomes and 23th may be x or y) and female contains(only x chromosomes.
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23 of male(haploid) +23 of female(haploid)= 46 chromosomes (diploid)
as we can see the no. of chromosomes half in sex cells so it is the solution that the DNA replicates but it retain in normal when sex cells fuses
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