Punnett Squares

Front

What is a Punnett Square used for?

Back

A Punnett Square is a diagram used to predict the outcome of a particular cross or breeding experiment, showing the possible genotypes of offspring based on the genotypes of the parents.

Tags

NGSS.HS-LS3-1

Front

Define dominant allele.

Back

A dominant allele is an allele that expresses its phenotype even in the presence of a recessive allele. It masks the effect of the recessive allele in a heterozygous genotype.

Front

What is a recessive allele?

Back

A recessive allele is an allele that only expresses its phenotype when two copies are present (homozygous). It is masked by the presence of a dominant allele.

Front

What does the genotype 'Bb' represent?

Back

The genotype 'Bb' represents a heterozygous individual, where 'B' is the dominant allele and 'b' is the recessive allele.

Front

What is the expected phenotypic ratio from a monohybrid cross?

Back

The expected phenotypic ratio from a monohybrid cross is typically 3:1, where 3 offspring show the dominant phenotype and 1 shows the recessive phenotype.

Front

How do you calculate the probability of a specific genotype in offspring?

Back

To calculate the probability of a specific genotype in offspring, use a Punnett Square to determine the possible combinations of alleles from the parents and then count the occurrences of the desired genotype.

Tags

NGSS.HS-LS3-3

Front

What is the phenotype of an organism?

Back

The phenotype of an organism is the observable physical or biochemical characteristics, as determined by both genetic makeup (genotype) and environmental influences.

Front

What does it mean if a plant has the genotype 'RR'?

Back

If a plant has the genotype 'RR', it means it has two dominant alleles for a trait, and it will express the dominant phenotype.

Tags

NGSS.HS-LS3-1

Front

What is the significance of a 25% chance in genetic crosses?

Back

A 25% chance in genetic crosses indicates that there is a one in four likelihood of obtaining a specific genotype or phenotype in the offspring, often seen in monohybrid crosses.

Tags

NGSS.HS-LS3-3

Front

Explain the term 'homozygous'.

Back

Homozygous refers to having two identical alleles for a particular gene, either both dominant (e.g., 'AA') or both recessive (e.g., 'aa').