Chapter 8 HW

Some people with Turner syndrome are 45,X/46,XY mosaics. How could this mosaicism arise?

A cell loses a Y chromosome soon after fertilization in an XY embryo.

Which of the statements describe mosaicism?

A child with the phenotypic features characteristic of Turner syndrome has a mixture of normal cells and cells with one copy of the X chromosome. A tortoiseshell cat has patches of orange and black fur. A cancerous tumor develops in a woman's ovary.

Select the statements that describe the effect of copy number variation on human phenotypes.

Copy number variations are associated with polygenic disorders such as schizophrenia. Oncogene overexpression due to a gain in copy number can cause cancer. Increase in the copy number of genes involved in starch digestion allows for a high‑starch diet.

Select the statements that explain why duplication is a driving force for evolution and the generation of new genes.

Phenotypic variations can occur when random fixed mutations are introduced into a new chromosomal environment. Duplicated genes provide extra copies of DNA that are not constrained by an essential function. Genes duplicate and then diverge from the original sequence to create multigene families.

Use the karyotype interactive to answer the question. Aneuploidy is an umbrella term referring to multiple kinds of conditions in which an individual has an abnormal number of chromosomes for their species. Some of the patients on the abnormal tab of the karyotype virtual interactive suffer from different types of aneuploidy. Use the interactive to determine from which form of aneuploidy patient 367 suffers.

monosomy

Which term describes the process of sister chromatids not separating at the centromere during cell division?

nondisjunction

Select the definition of aneuploidy.

the addition or loss of less than a full set of chromosomes or chromosome pairs

The image portrays a representation of a human karyotype. What type of genetic disorder is shown in this karyotype?

trisomy