The chromosomal theory of inheritance explains Mendel's law of segregation because homologous chromosome pairs do what during meiosis?
ADuplicate themselves so each gamete receives two copies
BFuse together to form a single chromosome in each gamete
CSeparate into different gametes, so each gamete receives one chromosome from each homologous pair
DSwap all their genetic material through crossing over
During meiosis I, homologous chromosomes separate into different cells — exactly mirroring Mendel's observation that allele pairs segregate so each gamete carries one allele per locus. This chromosome behavior is the physical mechanism underlying the law of segregation.
Question 2 True / False
Homologous chromosomes carry identical genetic information because they are copies of each other.
TTrue
FFalse
Answer: False
Homologous chromosomes carry the same genes at the same loci, but they are not necessarily identical — they may carry different alleles of those genes (e.g., one carries the allele for brown eyes, the other for blue). Treating them as identical is a major misconception; the whole point of heterozygosity is that the two homologs differ.
Question 3 Short Answer
Why does the chromosomal theory of inheritance predict that genes located on the same chromosome will NOT always follow Mendel's law of independent assortment?
Think about your answer, then reveal below.
Model answer: Independent assortment arises because chromosomes from different homologous pairs orient randomly at meiosis I. Genes on the same chromosome are physically linked and tend to be inherited together rather than shuffled independently — they violate independent assortment unless crossing over separates them.
Mendel's law of independent assortment holds for genes on different chromosomes (which sort independently during meiosis). Genes on the same chromosome travel together as a unit unless recombination separates them, so linkage is a direct, testable prediction of the chromosomal theory.