a colorblind woman marries a man who isn't colorblind. All of their sons are color blind but none of their daughters are color blind. color blindness is likely
1)the result of having two few chromosomes
2)the result of having and extra chromosomes
3)a sex-linked trait
4)a recessive trait
The likely explanation for this pattern of color blindness in their children is that color blindness is a sex-linked trait.
To understand this, we need to know certain aspects about genetics. In humans, genetic traits are determined by genes, which are located on chromosomes. We have 23 pairs of chromosomes, with one set received from each parent. The 23rd pair of chromosomes determines an individual's biological sex: females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).
Color blindness, specifically the most common type called red-green color blindness, is caused by a genetic mutation on the X chromosome. Since women have two X chromosomes, they can be both carriers (possessing one normal and one mutated gene) and affected by the disorder (having mutations on both X chromosomes). However, men, with only one X chromosome, can only be carriers or affected if they have the mutation.
Now, let's analyze the given scenario. The woman is colorblind, meaning she has one X chromosome with the mutation. The man does not have color blindness, as he does not carry the mutation on his X chromosome. When they have children, their sons receive one X chromosome from their mother (with the mutation) and one Y chromosome from their father. As a result, their sons have a 50% chance of inheriting their mother's color blindness gene, making them color blind.
On the other hand, their daughters receive one X chromosome from their mother (with the mutation) and one X chromosome from their father (without the mutation). Since color blindness is a recessive trait, their daughters will not be color blind unless they receive two mutated X chromosomes, which is highly unlikely. Therefore, none of their daughters are color blind.
Based on this information, we can conclude that color blindness in this scenario is likely a sex-linked trait rather than a result of having too few or extra chromosomes, or being a recessive trait.