Explanation:
Survival of the fittest is a phrase that originated from Darwinian evolutionary theory as a way of describing the mechanism of natural selection.In On the Origin of Species, he introduced the phrase in the fifth edition published in 1869, intending it to mean "better designed for an immediate, local environment".
Answer:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
Explanation:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
For example -
Suppose "X" is a mutant allele and "x" is a mutant free allele.
Now when two homologous chromosomes contains a single mutant allele in different parts of the chromosome are crossed the following offspring are produced
X x
X XX Xx
x Xx xx
"xx" is a mutant free genotype.
Thus, crossing over can create a single mutation-free chromosome