Print and turn in with your answers.

1. Using an example from class - if the ability to roll your tongue is dominant (R) and inability to roll your tongue is recessive (r), under normal conditions a person  who CAN roll their tongue could have which of the following combinations :
a) RR
b) Rr
c) rr
d) all of the above
e) a or b

2) Under normal conditions if the person cannot roll their tongue, then you know
a) one of their parents could not roll their tongue
b) both of their parents could not roll their tongue
c) that one of their parents carried the recessive gene
d) that both of their parents carried the recessive gene
e) that both of their parents carried the dominant gene

3) Suppose that T is the dominant gene for "Straight thumb" and t is the recessive gene for "curved thumb". Which of the following couples is mostly likely to have children who all have straight thumbs?
a) father tt, mother TT
b) father Tt, mother Tt
c) father tt, mother tt
d) father Tt, mother tt

4) Suppose "A" is a dominant gene and "a" is the corresponding recessive gene. One parent is heterogygous for the trait and the other is homozygous recessive.
If they have a lot of children, which of the following is most likely?
a) All kids will likely be AA.
b) All kids will likely be aa.
c) Three-fourths are likely to to be Aa, one-fourth  aa.
d) Half are likely to be Aa, half  aa.
e) One-fourth will likely be AA, one fourth aa, and one half Aa.

5) Suppose we know both parents are heterozygous for a trait. Which would we predict if they have a lot of  kids?
a) All kids will be heterozygous too.
b) All kids will be homozygous - half for the dominant trait, half for the recessive trait.
c) The kids may be homozygous for the dominant trait, homozygous for the recessive trait, or heterozygous.
d) No predictions are really possible.

Use this same kind of backwards and forwards genetic reasoning on your genetics assignment. See me if you have questions!