Genetics Long

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

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 both alleles are dominant & both traits show at the same time

• The different forms of a trait (brown, blonde, red)

The passing of genetic traits from parent to offspring.

• heredity
• trait
• gene
• allele

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

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

An allele whose trait always shows up in the organism when the allele is present.

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

Having two of the same alleles for the trait (sometimes called purebred).

• homozygous
• hetrozygous
• genotype

• phenotype

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

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

• 100% short

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

W=white hair
w= non-white hair
If you cross a horse with WW and a horse with ww what % of the offspring would be expected to have white hair?

• 0

• 75

• 50

• 100