Genotypes and Phenotypes: An Exploration

What is the phenotype of an organism?

• The genetic makeup of an organism

• The physical appearance of an organism

• The location of a gene on a chromosome

• The number of chromosomes in an organism

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NGSS.HS-LS3-1

If a trait is dominant, what does it mean?

• It will only appear if the organism is homozygous for that trait

• It will appear more frequently in the population

• It will be expressed even if only one allele is present

• It can never be expressed in a heterozygous genotype

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NGSS.HS-LS3-3

What is a Punnett square used for?

• To determine the phenotype of an organism

• To predict the possible genotypes of offspring from two parents

• To calculate the number of chromosomes in an organism

• To identify which alleles are dominant and which are recessive

Tags

NGSS.HS-LS3-3

What does it mean if an organism is homozygous for a trait?

• It has two different alleles for a trait

• It has two identical dominant alleles for a trait

• It has two identical recessive alleles for a trait

• Both B) and C) are correct

Tags

NGSS.HS-LS3-2

In a heterozygous genotype, how many different alleles are present for a given trait?

• One

• Two

• Three

• Four

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NGSS.HS-LS3-1

Which combination of alleles would represent a recessive trait being expressed?

• AA

• Aa

• aa

• Cannot be determined

Tags

NGSS.HS-LS3-2

If the allele for tall plants (T) is dominant over the allele for short plants (t), what is the genotype of a plant that is heterozygous for height?

• TT

• Tt

• tt

• T

Tags

NGSS.HS-LS3-1

When using a Punnett square, what does each box within the square represent?

• A unique phenotype

• A possible genotype of the parents

• A possible genotype of the offspring

• The actual genotype the offspring will have

If two heterozygous individuals are crossed (Aa x Aa), what is the probability of an offspring being homozygous recessive (aa)?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-3

What is the expected phenotype ratio of a monohybrid cross between two heterozygous individuals (Aa x Aa) if 'A' is dominant and 'a' is recessive?

• 1:1

• 2:1

• 3:1

• 4:0

Tags

NGSS.HS-LS3-3