7th Grade Genetics Review

If an individual shows a recessive phenotype then the only genotype they can be is....

• homozygous dominant
• heterozygous
• homozygous recessive
• you can't tell

What is a phenotype?

• The expression of a trait; physical appearance.
• refers to the genetic makeup of an individual
• An organism that has the same genes for a trait (ex. TT or tt)
• the passing of traits from parent to offspring

Tags

NGSS.HS-LS3-1

What does heterozygous mean?

• An organism that has the same genes for a trait (TT or tt)
• An organism that has different genes for a trait (Tt)
• When neither gene is fully dominant; offspring is a mixture of both
• the different forms of a trait (hair color--> brown, blonde, red

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The passing of genetic traits from parent to offspring.

• heredity
• trait
• gene
• allele

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

An allele whose trait only shows up when no dominant allele is present.

• hidden allele
• dominant allele
• recessive allele
• present allele

Two heterozygous (Tt)tall pea plants are crossed. Which describes their offspring?

• 50% tall and 50% short
• 75%tall and 25% short
• 100%short

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

R=round seed
r=wrinkled seed.
Cross a homozygous round with a wrinkled. Which statement predicts the results?

• offspring will be Rr
• offspring will be RR
• round seeds will be recessive to wrinkled
• Wrinkled will be observed in half of offspring

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

having two of the same genes for the trait (sometimes called purebred).

• homozygous
• hetrozygous
• protein
• chromosome

Tags

NGSS.HS-LS3-1

Which of the following alleles is homozygous recessive?

• Tt
• tt
• TT
• T

Tags

NGSS.HS-LS3-1

Which of the following is NOT a genotype?

• heterozygous
• a trait
• Bb
• homozygous recessive