According to modern evolutionary theory, which statement correctly describes the primary c… — JAMB UTME

According to modern evolutionary theory, which statement correctly describes the primary contribution of sexual reproduction to genetic variation within a population?

It reshuffles existing alleles into unique combinations through crossing over and independent assortment.Answer
B
It directly synthesizes entirely new alleles by modifying nucleotide sequences in somatic cells.
C
It allows phenotypic traits acquired through environmental exposure to be inherited by offspring.
D
It transforms continuous variations into fixed, discontinuous genetic categories across generations.

Answer

Sexual reproduction reshuffles existing alleles into unique combinations through crossing over and independent assortment.

In modern evolutionary theory (Neo-Darwinism), sexual reproduction contributes to genetic diversity mainly by shuffling existing alleles during meiosis (crossing over and independent assortment) and random fertilization. This creates new genotypic combinations without generating brand-new genetic alleles.

Step-by-Step Solution

Distinguish between sources of new alleles and sources of genetic recombination.

Gene mutations are the ultimate source of novel alleles, whereas sexual reproduction rearranges existing alleles.

Modern synthesis clearly separates mutation (creation of new genetic material) from recombination (shuffling of existing alleles).

Identify the key mechanisms of genetic variation during sexual reproduction.

Processes such as crossing over during meiosis, independent assortment of chromosomes, and random fertilization generate new genotype combinations.

These mechanisms create unique offspring phenotypes without altering the fundamental genetic code of individual alleles.

Key Concept

Role of Sexual Reproduction and Recombination in Modern Evolutionary Theory

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