2. Which of the following describes the genotype and phenotype of parents whose child will definitely have a recessive trait?
A. Both parents have a homozygous for the recessive allele and have that trait**
B. Both parents have a homozygous for the recessive allele but do not have that trait
C. Both parents have a homozygous for the recessive allele and have that trait
D. Both parents have a homozygous for the recessive allele but do not that that trait
^I’m really confused cause they both have the same answer twice O_O...but I chose A
3. A long-haired cat (recessive trait s) is crossed with a heterozygous short-haired cat (dominant trait S). Which percentage of their offspring will have long hair?
A. 100 percent
B. 50 percent**
C. 25 percent
D. 0 percent
4. In humans, having dimples is a dominant trait. If one parent has dimples and is homozygous for the trait, what is the probability any of his or her offspring will NOT have dimples?
A. 100 percent
B. 50 percent
C. 25 percent**
D. 0 percent
5. In humans, having more than 5 fingers or toes is dominant over having exactly 5 fingers or toes. Which of the following situations is most likely result in exactly half of a couple’s offspring having 6 digits and half of them having 5?
A. Both parents are homozygous for this trait**
B. Both parents are homozygous
C. One parent is heterozygous while the other is homozygous for this recessive trait
D. One parent is homozygous for the recessive trait while the other is homozygous for the dominant trait
The answers are:
1.B
2.A
3.B
4.D
5.C
Thank you so much FrostyplayROBLOX! Your answer helped me so much! I got 100%!
100 thanks
2. I'm confused too. I would pick A or C. B and D are identical too. Either you have typos or bad question.
3. Right
4. Disagree. If dimples are dominant and one parent is homozygous, the child will always get a dominant gene.
5. What is B? Disagree. A would lead to all having the trait.
100% wooooh thanks frosty
Thanks for the help
100% thank you!
100% still works in 2020
Frosty is right 100%.
2. To determine the genotype and phenotype of parents whose child will definitely have a recessive trait, we need to understand the inheritance pattern for the trait in question. In this case, a recessive trait means that both copies of the gene must carry the recessive allele for the trait to be expressed.
Option A states that both parents have a homozygous genotype for the recessive allele and have that trait. If both parents have two copies of the recessive allele (aa), then their child will also inherit two copies of the recessive allele (aa), resulting in the expression of the recessive trait.
Therefore, option A is the correct answer since it describes the genotype (homozygous recessive) and phenotype (having the recessive trait) of parents whose child will definitely have a recessive trait.
3. To determine the percentage of offspring that will have long hair in a cross between a long-haired cat (recessive trait s) and a heterozygous short-haired cat (dominant trait S), we can use Punnett squares.
The genotype of the long-haired cat is ss (homozygous recessive), and the genotype of the short-haired cat is Ss (heterozygous). When we cross these two genotypes, we get the following possibilities:
SS - short hair (dominant trait)
Ss - short hair (dominant trait)
sS - short hair (dominant trait)
ss - long hair (recessive trait)
Out of the four possible genotypes, only one genotype (ss) will result in long hair. Therefore, the percentage of offspring with long hair is 1 out of 4, which is 25%.
Thus, option C, 25 percent, is the correct answer.
4. To determine the probability that an offspring will NOT have dimples if one parent has dimples and is homozygous for the trait, we need to understand the inheritance pattern for this trait.
Having dimples is a dominant trait, which means that one copy of the dominant allele is sufficient to express the trait.
If the parent with dimples is homozygous for the trait (DD), it means that both copies of their gene carry the dominant allele for dimples. Therefore, all their offspring will inherit at least one copy of the dominant allele and will have dimples.
Hence, the probability of any of their offspring not having dimples is 0 percent.
Therefore, option D, 0 percent, is the correct answer.
5. To determine the situation that is most likely to result in exactly half of a couple's offspring having 6 digits and half having 5, we need to understand the inheritance pattern for this trait.
Having more than 5 fingers or toes is dominant over having exactly 5 digits. This means that if an individual has at least one copy of the dominant allele, they will have more than 5 digits.
Option A states that both parents are homozygous for this trait. If both parents are homozygous for the dominant trait (DD), then all their offspring would receive at least one copy of the dominant allele, resulting in all of them having more than 5 digits.
Therefore, option A, both parents are homozygous for this trait, is the correct answer as it explains how exactly half of the couple's offspring can have 6 digits while the other half has 5 digits.