Question

tudents used colored cardboard, modeling clay, and yarn to create a model of meiosis.



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What change could the students make to the model to BEST illustrate genetic variation that ensures genetic continuity?



A.
The students could include chromosomes separating and moving to opposite poles of the cell to show that gametes receive half of the genetic information, demonstrating that genetic variation is taking place.

B.
The students could include the process of crossing over by crossing homologous pairs to produce gametes with different genes, demonstrating that genetic variation is taking place.

C.
The students could include the cell growing and replicating its DNA to show that gametes receive double the genetic information, demonstrating that genetic variation is occurring.

D.
The students could include labels showing sister chromatids lining up in a specific pattern to produce gametes with different genes, demonstrating that genetic variation is occurring.

Answer 1

B.

Including crossing over (exchange of chromosome segments between homologous pairs during prophase I) best shows how new combinations of alleles are produced, increasing genetic variation.
A shows reduction in chromosome number but not the main source of new variation; C is wrong (replication duplicates DNA, not increase variation); D incorrectly focuses on sister chromatids lining up (it's homologous pairs/independent assortment that affects variation).