Genetics

What is a phenotype?

• The expression of a trait; what you see.
• 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

The inherited combination of alleles is known as the offspring's

• heredity
• phenotype
• genotype
• redigree

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

A heterozygous yellow pea plant's genotype would be:

• YY
• yy
• Yy
• Yg

A corn plant heterozygous for tall sprouts mates with a corn plant with short sprouts. If tall sprouts are dominant, how many different phenotypes are possible in the offspring?

• 1
• 2
• 3
• 4

If T=Tall & t=short, what is the genotypic ratio?

• 1:3
• 3:1
• 1:2:1
• 2:2

If a heterozygous tall pea plant is crossed with a short pea plant, what are the possible genotypes of the future offspring?

• 100% Tt
• 50% Tt, 50% tt
• 75%Tt, 25%tt
• 25%TT, 50%Tt, 25%tt

A nucleotide consists of

• DNA

• adenine and thymine

• A phosphate, sugar and nitrogenous base

• genes

In a DNA molecule, nucleotides are linked together to make up a single strand of DNA then bonded to a second strand. This structure is known as a

• RNA

• double helix

• watson-crick

• double nucleotide

In a double strand of DNA, the nitrogen bases only pair in a certain combination. Which combination is correct?

• A-C and T-G

• C-T and A-G

• A-T and G-C

• A-A C-C