Genetics And Punnett Squares Quiz (3)

Plants that have homozygous genotypes are those that have two identical alleles for a particular trait. In this case, the answer "both TT and tt" suggests that plants with genotype TT (homozygous dominant) and plants with genotype tt (homozygous recessive) have homozygous genotypes. This means that both types of plants have two identical alleles for the trait being considered.

Organisms that have two identical alleles for a particular trait are said to be homozygous. This means that both alleles for that trait are the same, either both dominant or both recessive. Homozygous organisms will always express the trait associated with those alleles, whether it is dominant or recessive.

Incomplete dominance is the correct answer because it refers to a genetic situation where neither allele is completely dominant over the other, resulting in a blending or intermediate phenotype in the offspring. In this case, when a red plant is crossed with a white plant and the resulting offspring is pink, it indicates that neither the red nor white allele is fully dominant, leading to incomplete dominance.

When a heterozygous tall pea plant (Tt) is crossed with a short plant (tt), the possible genotypes of the offspring are Tt and tt. Since tall (T) is dominant over short (t), both the Tt and tt genotypes will result in a tall plant phenotype. Therefore, the probability that the offspring plant will be tall is 50%.

When a brown fox (homozygous for brown, BB) is crossed with a white fox (homozygous for white, bb), all of the offspring will be heterozygous for brown (Bb). Since brown (B) is dominant over white (b), the offspring will all have the brown phenotype. Therefore, the probability of the fox offspring being white is 0.

DNA (deoxyribonucleic acid) is composed of building blocks called nucleotides. Each nucleotide consists of three main components:

Deoxyribose sugar: A five-carbon sugar that forms the backbone of the DNA molecule.

Phosphate group: A phosphorus atom bonded to four oxygen atoms, which links the sugar molecules together in the DNA strand.

Nitrogenous base: One of four nitrogen-containing bases: adenine (A), guanine (G), cytosine (C), or thymine (T). These bases pair up to form the "rungs" of the DNA ladder.

Ribose sugar is found in RNA (ribonucleic acid), not DNA. The difference between the two sugars is the presence of an extra oxygen atom in ribose.

When IA and IB exist together, they make blood type AB, which means that both alleles are expressed equally and neither is dominant over the other. This is an example of co-dominance, where both alleles contribute to the phenotype. In co-dominance, the traits of both alleles are visible in the phenotype, unlike incomplete dominance where one allele is partially dominant over the other.

This pedigree shows the inheritance of a trait through generations, indicating that there are multiple alleles involved in the expression of the trait. Multiple alleles refer to the presence of more than two alternative forms of a gene at a specific locus. In this case, the trait being described is influenced by multiple alleles, which can result in a range of phenotypic variations.

Codominance refers to a genetic scenario where both alleles in a gene pair are fully expressed, resulting in a phenotype that shows characteristics of both alleles. This means that there are more than two versions of alleles for the genes involved. In codominance, neither allele is dominant or recessive, and both are expressed equally. This is in contrast to multiple alleles, which refers to a gene that has more than two alleles in a population, but only two of those alleles can be present in an individual. Therefore, codominance is the correct answer for having more than 2 versions of alleles for genes.

When a heterozygous cat (Yy) is mated with a white cat (yy), the possible genotypes of the offspring are YY, Yy, and yy. This is because yellow fur (Y) is dominant over white fur (y), so even if one parent is heterozygous (Yy), there is a chance for the offspring to inherit the yellow fur allele (Y) and have the genotype YY. Additionally, there is a possibility for the offspring to inherit one yellow fur allele (Y) and one white fur allele (y), resulting in the genotype Yy. Finally, there is also a chance for the offspring to inherit two white fur alleles (yy), resulting in the genotype yy.