Genetics: Part 1 - Practice Flashcard

Front

If a flower has the genotype pp, what is the phenotype?

Back

White

Answer explanation

The genotype pp indicates that the flower has two recessive alleles. Since purple flowers are dominant, the presence of two recessive alleles results in a white phenotype. Therefore, the correct answer is White.

Front

If a flower has the genotype Pp, what is the phenotype?

Back

Purple

Answer explanation

The genotype Pp indicates that the flower has one dominant allele (P) for purple flowers. Since purple is dominant over white, the phenotype of a flower with genotype Pp will be purple.

Front

Possible genotypes of offspring when crossing a white flower (pp) with a purple flower (PP).

Back

All Pp

Answer explanation

Crossing a white flower (pp) with a purple flower (PP) results in all offspring having the genotype Pp. This is because each offspring inherits one allele from each parent, leading to the genotype Pp.

Front

A ________________ trait masks the alternate form of the trait and is always expressed.

Back

dominant

Answer explanation

A dominant trait masks the alternate form, known as the recessive trait, and is always expressed in the phenotype. This is why the correct answer is 'dominant'.

Front

A _____________ trait is always masked by the stronger alternate version of the trait.

Back

recessive

Answer explanation

A recessive trait is one that is masked by a dominant trait. It only expresses itself when two copies of the recessive allele are present, making 'recessive' the correct answer.

Front

If a true-breeding male plant with wrinkled seeds (ww) is crossed with a true-breeding female plant with round seeds (WW), what are the probable phenotypes of the offspring?

Back

100% round seeds

Answer explanation

The male plant (ww) has wrinkled seeds and the female plant (WW) has round seeds. All offspring (Ww) will inherit one round seed allele from the mother, resulting in 100% round seeds.

Front

Individuals inherit ____ allele from each parent for each trait encoded in a gene.

Back

1

Answer explanation

Individuals inherit 1 allele from each parent for each trait encoded in a gene. This means that for every gene, one allele comes from the mother and one from the father, making the correct answer 1.

Front

Each gene in an individual's genome has ____ alleles.

Back

2

Answer explanation

Each gene has 2 alleles, one inherited from each parent. This diploid nature means individuals typically have two versions of each gene, making '2' the correct answer.

Front

Select the genotype/s that show a RECESSIVE phenotype?

Back

gg

Answer explanation

The genotype 'gg' is homozygous recessive, which expresses the recessive phenotype. In contrast, 'GG' and 'Gg' are either homozygous dominant or heterozygous, leading to a dominant phenotype.

Front

If T = Tall and t = not tall (short), what is the genotypic ratio?

Back

1:2:1

Answer explanation

In a monohybrid cross (Tt x Tt), the genotypic ratio is 1 TT : 2 Tt : 1 tt, which simplifies to 1:2:1. This indicates one homozygous tall, two heterozygous tall, and one homozygous short offspring.