Genetic Variations

In a monohybrid cross, if a homozygous dominant plant (TT) is crossed with a homozygous recessive plant (tt), what will be the genotype of the offspring?

• TT

• Tt

• tt

• TTT

Tags

NGSS.HS-LS3-1

If a plant with genotype Tt is crossed with a plant with genotype tt, what are the possible genotypes of the offspring?

• TT and Tt

• Tt and tt

• TT and tt

• tt only

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

T - tall and t = short. In the Punnett square below, what belongs in the missing square (a)  

• tt

• Tt

• Bb

• TT

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What is the probability of obtaining a homozygous recessive offspring (tt) from a cross between two heterozygous parents (Tt)?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-3

A plant with genotype Tt is crossed with another plant with genotype Tt. What is the probability that an offspring will be homozygous dominant?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-3

If a heterozygous plant (Tt) is crossed with a homozygous recessive plant (tt), what is the probability of obtaining a tall plant?

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Describe how a Punnett square can be used to predict the likelihood of an offspring inheriting a particular trait.

• By showing all possible combinations of alleles from the parents

• By showing the environmental factors affecting the offspring

• By showing the number of chromosomes in the offspring

• By showing the lifespan of the offspring

Tags

NGSS.HS-LS3-2

In a monohybrid cross, what does it mean if an organism is described as homozygous?

• It has two different alleles for a trait

• It has two identical or same alleles for a trait

• It has one allele for a trait

• It has no alleles for a trait

If a plant with genotype TT is crossed with a plant with genotype Tt, what is the probability of obtaining a homozygous recessive offspring? (Draw a Punnett Square to figure out answer)

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-1

Explain the difference between genotype and phenotype with an example.

• Genotype refers to the physical appearance, while phenotype refers to the genetic makeup; for example, tall height is a genotype.

• Genotype refers to the genetic makeup, while phenotype refers to the physical appearance; for example, Tt is a genotype, and tall height is a phenotype.

• Genotype and phenotype are the same; for example, Tt and tall height are both genotypes.

• Genotype refers to the number of chromosomes, while phenotype refers to the number of genes; for example, 46 chromosomes is a genotype.