heres the question, I totally don't understand it:
a few sex linked ttraits in humans are located on the Y chromosome and are dominant. What pattern of inheritence would uou expect to see in these traits? show your exmaplantion.
If the traits are on the y-chromosome, and are DOMINANT...that means that ALL the offspring BOYS will have the trait, but NONE of the offspring GIRLS will have the trait. Do you see why?
is it because in order for there to be a boy the dad would have to give a y because a mom can only give x and since the y is domiannt it would always express the trait>?
Yes, absolutely right!!!
Thanks so much :)
The question is asking about the pattern of inheritance for sex-linked traits located on the Y chromosome. To understand this, let's break it down step by step:
1. Sex chromosomes: In humans, there are two types of sex chromosomes, referred to as X and Y. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
2. Location of sex-linked traits: The question states that the sex-linked traits we are considering are located specifically on the Y chromosome. This means that only males carry these traits since females lack a Y chromosome.
3. Dominant traits: The question further mentions that these sex-linked traits are dominant. This indicates that if an individual inherits the dominant allele for the trait, it will be expressed, overshadowing the recessive allele.
Given these facts, we can determine the pattern of inheritance for these sex-linked traits:
- Males: Since males have only one copy of the Y chromosome, any trait located on it will be inherited from their father. If the father carries the dominant allele for the trait, all of his sons will inherit the trait and express it because there is no second copy of the Y chromosome to mask or counteract it. Therefore, the pattern of inheritance for males is a direct transmission of the trait from the father to all sons.
- Females: Since females lack the Y chromosome, they cannot directly inherit the traits located on it. However, if a female's father carries the dominant allele on the Y chromosome, the daughter has a 50% chance of inheriting the dominant allele through her father. In this case, she will express the trait as well. Therefore, the pattern of inheritance for females depends on whether their fathers carry the dominant allele on their Y chromosome.
To summarize, the pattern of inheritance for dominant sex-linked traits located on the Y chromosome is straightforward. Males will always inherit and express the trait if their father carries it, while females have a 50% chance of inheriting and expressing the trait if their father carries it.