Does Alkaptonuria appear to be caused by a dominant allele or by a recessive allele?

recessive allele
Alkaptonuria must be caused by a recessive allele. If you assume the disorder is dominant, then it is impossible for Ann and Michael, both unaffected, to have offspring that are affected (since Ann and Michael must both be homozygous recessive). 9.

Which of the following procedures would be best for identifying a chromosomal abnormality in a fetus?

Amniocentesis — Amniocentesis is used most commonly to identify chromosomal problems such as Down syndrome. When the fetus is known to be at risk, it can detect other genetic diseases like cystic fibrosis, Tay-Sachs disease and sickle cell disease.

How do cats get true breeding curls?

You would obtain some true-breeding offspring homozygous for the curl allele from matings between the F1 cats resulting from the original curl X noncurl crosses whether the curl trait is dominant or recessive. You know that cats are true-breeding when curl x curl matings produce only curl offspring.

Why is alkaptonuria recessive?

Alkaptonuria is caused by a mutation on your homogentisate 1,2-dioxygenase (HGD) gene. It’s an autosomally recessive condition. This means that both of your parents must have the gene in order to pass the condition on to you.

Which of the following most likely explains how the chromosomes circled in Figure 1 could cause a genetic disorder in the person from whom the cells were obtained?

Which of the following most likely explains how the chromosomes circled in figure 1 could cause a genetic disorder in the person from whom the cells were obtained? The extra chromosome will affect the levels of RNA transcribed from certain genes and the amount of protein produced from those genes in each cell.

What is the difference between a dominant allele and a recessive allele?

A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent.

What do you call the mating or crossing over of two true breeding varieties?

Monohybrid Cross and the Punnett Square When fertilization occurs between two true-breeding parents that differ by only the characteristic being studied, the process is called a monohybrid cross, and the resulting offspring are called monohybrids.

What is a true breeding parent?

A true breeding is a kind of breeding wherein the parents would produce offspring that would carry the same phenotype. This means that the parents are homozygous for every trait. An example of true breeding is that of the Aberdeen Angus cattle.

What is alkaptonuria biology?

Alkaptonuria is a recessive abnormality, having a rate of about 3-5:1000000. It is caused by a deficiency of the Homogentisate acid oxidase enzyme. Signs of the disease are special staining of cartilages and arthritis in the elderly.

What gene causes alkaptonuria?

The gene involved in alkaptonuria is the HGD gene. This provides instructions for making an enzyme called homogentisate oxidase, which is needed to break down homogentisic acid.

What is the role of dominant or recessive genes in Down syndrome?

This means that the condition is genetic and passed down by the mother and/or the father but the condition is not shown in the parents. 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.

Which of the following best describes the likely mode of inheritance for the eye color gene?

Which of the following best describes the likely mode of inheritance for the eye color gene? The eye-color gene is likely autosomal because males and females have similar phenotype ratios.

What is the effect of dominant alleles?

Dominant alleles show their effect even if the individual only has one copy of the allele (also known as being heterozygous?). For example, the allele for brown eyes is dominant, therefore you only need one copy of the ‘brown eye’ allele to have brown eyes (although, with two copies you will still have brown eyes).

Is PP white or purple?

the allele P (purple) is dominant. this means that if there are one or more alleles present in the genotype of the offspring (Pp or PP), the flower will be purple. the flower can only be white if there are two recessive genes – if the flower were white, the genotype would have to be pp.