Question

crossing over
compare the homologous
chromosomes to the
chromatids they become
at the end of meiosis
due to crossing over.
explain the importance
of crossing over.
homologous
chromosomes
melosis ii
is completed
resulting chromatids sorted
into 4 daughter cells
type here...

Explanation:

Homologous chromosomes are pairs of chromosomes with the same genes but possibly different alleles. Before crossing - over, each chromatid in a homologous pair is pure (either entirely from one parent). After crossing - over (during meiosis I), chromatids have segments from both parents. This genetic recombination leads to genetic variation. Genetic variation is crucial as it provides the raw material for evolution. It allows species to adapt to changing environments, as different combinations of alleles can confer different traits (e.g., resistance to diseases, ability to utilize different food sources). In a population, this variation increases the chances of survival of the species over time.

Answer:

Crossing - over causes genetic recombination. This leads to genetic variation among offspring. Genetic variation is important because it:

• Provides the basis for evolution (natural selection acts on different traits).
• Increases the adaptability of a species to environmental changes (e.g., new diseases, climate changes).
• Enhances the survival chances of a population (a diverse gene pool means some individuals may have traits suitable for a new environment).