Question

in humans, red - green color blindness is an x - linked recessive disorder. the alleles for the disorder are c for normal and c for affected/colorblind. what is the genotype of a phenotypically normal female that carries the trait?
cc
x^cx^c
x^cy^c
x^cx^c
question 9 (1 point)
the alternate forms of a gene for the same trait are known as
a) alleles.
b) phenotypes.
c) genotypes.
d) codominants.
e) incomplete dominants.
question 10 (1 point)
parents with the dominant phenotype cannot have offspring with the recessive phenotype.
true
false

Explanation:

• For the first question:
• Since it is an X - linked disorder, females have two X chromosomes (\(X^{C}X^{c}\) indicates one normal allele (\(C\)) and one recessive allele (\(c\)) on the X - chromosomes. \(Cc\) is for autosomal inheritance (not X - linked). \(X^{C}Y^{c}\) is incorrect as males have \(XY\) chromosomes and this is not the correct notation for X - linked female genotypes. \(X^{c}X^{c}\) would be a color - blind female (homozygous recessive).
• For the second question:
• Alleles are the alternate forms of a gene for the same trait. Phenotypes are the observable characteristics. Genotypes are the genetic makeup. Codominants refer to a type of inheritance where both alleles are expressed. Incomplete dominants is another inheritance pattern.
• For the third question:
• If parents are heterozygous (\(Aa\times Aa\) for an autosomal trait, for example), they can have offspring with the recessive phenotype (\(aa\)). So the statement "Parents with the dominant phenotype cannot have offspring with the recessive phenotype" is false.

Answer:

• First question: \(X^{C}X^{c}\)
• Second question: a) alleles
• Third question: False