Exam 3: Seciton 4: Beginnings: Heredity and Environment

Almost every cell in the human body has 23 single chromosomes.

Genes are located on chromosomes.

The most common extra-chromosome condition is fragile X syndrome.

Each variation of a particular gene is called an allele of that gene.

All humans have about 100,000 genes.

Due to genetic inheritance, each child is the product of both parents, but only looks, sounds, and acts like one of them.

The cells that result from the early duplication and division processes are called stem cells, which are able to produce any other specialized cell.

Every ovum a woman creates contains an X chromosome.

Genes affect disorders such as alcoholism and nearsightedness, but research indicates that the environment plays a role as well.

An individual's collection of genes is called a phenotype.

The first 22 chromosomes contain hundreds of genes in the same positions and sequence. If the code of the gene from one parent is exactly like the code of the same gene from the other parent, the gene pair is heterozygous.

Genes, culture, and age all affect vision.

Dizygotic twins originate from the same zygote; therefore, they have the same genotype.

When the 23 pairs of chromosomes duplicate and form two complete sets of the genome, this process is referred to as duplication.

Genes and alleles for alcoholism have been found exclusively on the Y chromosome.

The general term for the techniques designed to help infertile couples conceive and then sustain a pregnancy is in vitro fertilization (IVF).

Due to biological sex (XX or XY) women become drunk on more alcohol than men.

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

When the effects of genes add up to make the phenotype, they are called dominant-recessive genes.

If the 23rd pair of chromosomes contains one X chromosome and one Y chromosome, then the individual is male.