IQWST LS3 Lessons 4-7

Front

What does it mean if an organism is heterozygous?

Back

An organism is heterozygous if it has two different alleles for a particular gene, one inherited from each parent.

Front

What is the percentage of offspring that can be expected to have a specific trait if both parents are heterozygous?

Back

If both parents are heterozygous, the expected percentage of offspring with a specific trait can vary, but for a trait with a dominant and recessive allele, it is typically 75% for the dominant trait and 25% for the recessive trait.

Front

What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, determined by both genetic makeup and environmental influences.

Front

What is the genotype of an organism?

Back

The genotype is the genetic constitution of an organism, specifically the alleles it possesses for a particular gene.

Front

If tall (T) is dominant to short (t), what is the probability of producing a short plant from a Tt x Tt cross?

Back

The probability of producing a short plant (tt) from a Tt x Tt cross is 25%.

Front

What does homozygous dominant mean?

Back

Homozygous dominant refers to an organism that has two identical dominant alleles for a particular gene (e.g., TT).

Front

What does homozygous recessive mean?

Back

Homozygous recessive refers to an organism that has two identical recessive alleles for a particular gene (e.g., tt).

Front

What is the significance of the letter combinations in genetic crosses (e.g., Rr, RR, rr)?

Back

The letter combinations represent the different possible genotypes of offspring based on the alleles contributed by each parent.

Front

What is the expected phenotype ratio from a monohybrid cross between two heterozygous parents?

Back

The expected phenotype ratio from a monohybrid cross between two heterozygous parents is 3:1 for dominant to recessive traits.

Front

What is a Punnett square?

Back

A Punnett square is a diagram used to predict the genotypes of offspring from a genetic cross.