Exam 37: A: Genetics and Heredity

Red-green color blindness,which involves a deficiency of photopigments in the retina,is an example of a recessive X-linked condition.

An adult who is homozygous for Tay-Sachs disease is more resistant to TB.

All female gametes carry the X chromosome.

The X chromosome contains few genes other than those that determine female sexual characteristics.

Exons are removed from transcribed RNA to form the functional mRNA strand.

The egg cytoplasm rather than the egg nucleus is responsible for transmission of mitochondrial DNA.

Polygenic traits have more than one gene pair that contributes to their expression.

DNA molecules are segments of a gene.

You would expect the p-arm of a chromosome to carry more genes than the q-arm of the chromosome.

A karyotype is a grid used to determine the mathematical probability of inheriting genetic traits.

The Genome Project discovered that the human genome contains about 30,000 genes,about three times the number that was expected.

Fortunately,individuals with Klinefelter syndrome generally are not sterile.

Only about half of the human population has 23 pairs of chromosomes in their cells.

A genetic carrier is someone who has the gene but does not express the trait.An example would be someone who is heterozygous for a dominant/recessive trait.

If a child is albino,at least one of the parents must be albino.

When DNA is in its chromosomal form,it is non-functional.

The beta chain in hemoglobin remains normal in a person with sickle cell anemia.

A karyotype is effective only in identifying chromosomal abnormalities.

It may be that women of any age have an equal likelihood of nondisjunction,but in younger women,the fetuses would spontaneously abort.

Gene linkage and crossing over have opposite effects on genetic variation.