Exam 20: Genetics and Human Inheritance

________ are genes that exist in more than two allelic forms.The genes responsible for the human ABO blood types are an example of this phenomenon.

If someone were heterozygous for a recessive genetic illness,then they are ________.

Match each definition in the first column to the correct term in the second column. -The alteration of a chromosome that involves the addition of a piece of chromosome.

The principle that states that different homologous chromosomes travel randomly to different ends of the cell is ________.

Match each definition in the first column to the correct term in the second column. -The expression of the trait in heterozygous individuals is somewhere between the expression of the trait in the homozygous recessive and homozygous dominant individual.

In which condition are both alleles apparent in the heterozygous phenotype?

What are the advantages and disadvantages of chronic villus sampling (CVS)in comparison to amniocentesis?

Gene testing allows the parents to learn more about their child in the pre-natal period.However,there are genetic disorders,such as Huntington's disease that show no phenotypic signs until age 35.This disease is caused by a dominant allele,resulting in degeneration of the brain,muscle spasms,and death within a decade or two.Because it is caused by a dominant allele,50% of the offspring will carry the disease.If you knew that someone in your family had Huntington's disease,would you get tested early on before you start a family and have your own children? Would you rather not know your fate,even if it means that you may pass the dominant allele of this disease to your offspring?

Henry has the sickle cell trait.Why might it be a bad idea for him to go on that hiking vacation that is being planned for the high Andes?

An individual with the genotype AaBbCC is able to produce what type of gametes?

Match each definition in the first column to the correct term in the second column. -A segment on a chromosome that directs the synthesis of a specific polypeptide or protein,which may play either a structural or functional role in the cell.

In this heredity pattern,both alleles appear in the phenotype of the heterozygote.

________ traits involve the expression of certain autosomal genes that are not located on the sex chromosomes but that are powerfully influenced by the presence of sex hormones,so the expression of these genes differs between males and females.

PKU is a hereditary condition only seen if a person has two copies of the gene.Therefore,it is said to be ________.

Specific segments of DNA that are the functional units of inheritance are called ________.

If two chromosomes have the same genes,they are said to be ________.

Diabetes mellitus type 2 (DM2)is partly hereditary and,if uncontrolled,can lead to kidney disease and heart failure and an increased risk of stroke and blindness.From this information alone,you could say that DM2 is an example of ________.

What are the differences between complete dominance and codominance?

A cardiac researcher is trying to determine if a pattern of very high blood cholesterol is genetic in a group of Pennsylvania Dutch.Therefore,the scientist looks through years of medical records,plus patterns of marriage through several generations.The investigator is doing a type of hereditary research called ________.

Why is Duchenne muscular dystrophy less common in females than males?