Most X-linked conditions are recessive. This means that in a person with two X chromosomes (most females), both copies of a gene (i.e., one on each X chromosome) must have a change or mutation whereas in a person with one X chromosome (most males), only one copy of a gene must have a mutation.
Q. Is Down syndrome caused by a dominant or recessive allele?
An autosomal recessive disorder requires two copies of the abnormal gene for the disease or trait to develop. But Down Syndrome itself is neither dominant nor recessive. Trisomy 21 is an extra copy of chromosome 21.
Table of Contents
- Q. Is Down syndrome caused by a dominant or recessive allele?
- Q. Is Edwards syndrome recessive or dominant?
- Q. Which of the following is sex linked recessive disorder?
- Q. How do you know a trait is sex linked?
- Q. What is sex-influenced character?
- Q. Is blood type sex linked?
- Q. Which is a sex-influenced trait?
- Q. What is sex linked and sex influenced traits?
- Q. What blood groups should not marry?
- Q. Do blood types matter in pregnancy?
Q. Is Edwards syndrome recessive or dominant?
Edwards syndrome is trisomy 18 where there is an extra chromosome at 18. Pure trisomy 18 occurs due to non disjunction. It is not autosomal recessive. The Risk of recurrence is less than 1percent.
Q. Which of the following is sex linked recessive disorder?
Diseases such as hemophilia and Duchenne muscular dystrophy occur from a recessive gene on the X chromosome.
Q. How do you know a trait is sex linked?
Sex-linked traits are associated with genes found on sex chromosomes. In humans, the sex chromosomes are X and Y. Because the X-chromosome is larger, X-linked traits are more common than Y-linked traits. An example of a sex-linked trait is red-green colorblindness, which is carried on the X-chromosome.
Q. What is sex-influenced character?
Sex-controlled character, also called Sex-influenced Character, a genetically controlled feature that may appear in organisms of both sexes but is expressed to a different degree in each. The character seems to act as a dominant in one sex and a recessive in the other.
Q. Is blood type sex linked?
An example of a codominant trait is blood type. If a person has one gene coding for blood type A and one gene coding for blood type B, the person has both A and B blood types expressed (blood type AB). An X-linked (sex-linked) gene is one that is carried on an X chromosome. X-linking also determines expression.
Q. Which is a sex-influenced trait?
A phenotypic characteristic or trait such as male pattern baldness that is expressed differently in males and females, usually because its expression depends on androgens or oestrogens, and that is controlled by a single gene that is dominant in males but recessive in females, so that, for example, men who inherit the …
Q. What is sex linked and sex influenced traits?
Sex-linked traits are determined by genes located on the sex chromosomes. Sex-limited traits are determined by genes located on autosomes and express only in one sex. While these traits are responsible considerably for sexual dimorphism, sex-influenced traits do not show distinctive expression between women and men.
Q. What blood groups should not marry?
Blood typing
- If you have type A blood, you should only receive types A or O blood.
- If you have type B blood, you should only receive types B or O blood.
- If you have type AB blood, you can receive types A, B, AB, or O blood.
- If you have type O blood, you should only receive type O blood.
Q. Do blood types matter in pregnancy?
How Your Rh Factor Blood Type Affects Your Pregnancy. Usually your Rh factor blood type isn’t an issue. But during pregnancy, being Rh-negative can be a problem if your baby is Rh-positive. If your blood and your baby’s blood mix, your body will start to make antibodies that can damage your baby’s red blood cells.
