Exam 3: Heredity and Environment

Explain how color blindness is inherited and why it is much more common in one sex than the other.

All living things are composed of cells. The work of cells is done by _____.

A special case of the dominant-recessive pattern occurs with genes that are X-linked, or located on the _____ chromosome.

Lacy has a recessive gene in her genotype that is not expressed in her phenotype. She is a(n) _____ of that gene.

Misinformation and mistaken fears are particularly destructive for _____ disorders.

Jeff and Ashley are the result of two separate ova that were fertilized by two separate sperm. Jeff and Ashley are _____.

A person's collection of genes is referred to as his or her "_____."

Genes are located on chromosomes.

An individual's phenotype is dependent entirely on his or her genes.

If the 23rd pair of chromosomes contains two X chromosomes, then that individual is a male.

All the following affect vision EXCEPT _____.

Humans have 23 pairs of _____, which contain the instructions to make the proteins needed for life and growth.

Every ovum a woman creates contains an X chromosome.

Down syndrome is also called "_____."

Individual A's 23rd pair of chromosomes is XY. Individual A is _____.

One nation that forbids prenatal sex selection is _____.

Ways in which chromosomal and genetic problems are relevant to human development include all the following EXCEPT _____.

Almost every trait is _____, which means it is affected by many genes.

Describe how the sex of a fetus is decided at conception.

Briefly describe differentiation and when it begins. Give at least two examples of cell differentiation.