Heredity and Variation

A reciprocal translocation between non-homologous chromosomes alters the arrangement of genes on the affected chromosomes without changing the total count of chromosomes in a diploid cell, whereas meiotic non-disjunction causes aneuploidy by altering the total chromosome number in the resulting gametes.

Match each type of gene mutation or chromosomal aberration on the left with its corresponding description on the right.

In monohybrid inheritance experiments involving guinea pig coat color, where the allele for black fur ($B$) is completely dominant over the allele for white fur ($b$), match each specified parental cross or test cross scenario on the left with its corresponding phenotypic or genotypic outcome in the offspring on the right.

During gametogenesis, non-disjunction of chromosome 21 occurs specifically during Meiosis I. If all resulting gametes are subsequently fertilized by normal haploid gametes, what percentage of the produced zygotes will have trisomy 21?

In fruit flies (*Drosophila melanogaster*), grey body color ($B$) is dominant over black body color ($b$), and normal wing length ($V$) is dominant over vestigial wings ($v$). If two heterozygous grey-bodied, normal-winged flies ($BbVv$) are crossed and produce a total of 320 offspring, how many of these offspring are expected to exhibit a black body with normal wings?

Match each human phenotypic feature listed on the left with its characteristic variation pattern and underlying genetic mechanism on the right.

While the ABO blood group system in human populations is governed by three multiple alleles ($I^A$, $I^B$, and $i$), any given diploid individual can inherit a maximum of two alleles, with $I^A$ and $I^B$ exhibiting codominance with each other while both display complete dominance over the allele $i$.

In maize plants, the allele for smooth kernels ($S$) is completely dominant over the allele for wrinkled kernels ($s$). According to Mendel's Law of Segregation, a monohybrid cross between two heterozygous smooth-kernel maize plants ($Ss \times Ss$) produces offspring with a genotypic ratio of $3:1$.

In genetic studies of pea plants, the gene governing flower placement exists as two structural variants: axial ($A$) and terminal ($a$). Which of the following terms specifically describes these alternative forms of a single gene that occupy identical locations on homologous chromosomes?

Match each fundamental genetics term on the left with its precise biological definition on the right.

In pea plants, the allele for axial flower position ($A$) is completely dominant over the allele for terminal flower position ($a$). If two heterozygous axial-flowered plants ($Aa$) are crossed, what is the expected genotypic ratio ($AA : Aa : aa$) among their offspring according to Mendel's First Law?

In tomato plants (*Solanum lycopersicum*), purple stem ($P$) is dominant over green stem ($p$), and cut leaf ($C$) is dominant over potato leaf ($c$). A plant heterozygous for both traits ($PpCc$) is crossed with a homozygous recessive plant ($ppcc$). What proportion of the offspring is expected to have purple stems and potato leaves?

In tomato plants, the allele for red fruit ($R$) is completely dominant over the allele for yellow fruit ($r$). If a heterozygous red-fruited plant is self-pollinated and produces $400$ offspring in the $F_2$ generation, how many of these plants are expected to be heterozygous red-fruited?

In guinea pigs (*Cavia porcellus*), black coat color ($B$) is dominant over white coat color ($b$), and short hair ($S$) is dominant over long hair ($s$). If two heterozygous guinea pigs ($BbSs$) are mated and produce a total of $400$ offspring, how many offspring are expected to display the black coat and long hair phenotype?

Match each dihybrid parental cross genotype of independently assorting genes with its expected offspring phenotypic ratio.

A man with blood group A, whose mother had blood group O, marries a woman with blood group B, whose father had blood group O. What is the probability that their first child will have blood group O?

Match each non-Mendelian genetic concept listed on the left with its corresponding biological example or defining feature on the right.

A woman with normal vision whose father was color-blind marries a man with normal vision. What is the probability that any male child born to this couple will be color-blind?

Match each sex determination system or sex-linked inheritance pattern on the left with its correct biological characteristic or organism example on the right.

During a crop breeding experiment, two individual maize plants both exhibit resistance to a fungal pathogen. Genetic sequencing reveals that Plant 1 has the genetic constitution $RR$, whereas Plant 2 has the genetic constitution $Rr$. Which of the following statements correctly compares the genetic characteristics of these two plants?