CHDV Ch.3

The molecule that contains the chemical instructions for cells to manufacture various proteins

one of the 46 molecules of DNA(in 23 pairs) that each cell of the human body contains and that, together, contain all the genes. other species have more or fewer chromosomes.

A section of a chromosome and the basic unit for the transmission of heredity, consisting of a string of chemicals that are instructions for the cell to manufacture certain proteins.

any of the possible forms in which a gene for a particular trait can occur.

the full set of genes that are the instructions to make an individual member of a certain species

a reproductive cell; that is, a sperm or ovum that can produce a new individual if it combines with a gamete from the other sex to make a zygote

the single cell formed from the fusing of two gametes, a sperm and an ovum

an organism's entire genetic inheritance, or genetic potential

the chromosome pair that in humans, determines the zygote's (and hence the person's) sex. the other 22 pairs are autosomes, the same whether the 23rd pair is for a male or a female

a 23rd chromosome pair that consists of two X-shaped chromosomes, one each from the mother and the father. XX zygotes become females.

a 23rd chromosome pair that consists of an X-shaped chromosome from the mother and a Y-shaped chromosome from the father. XY zygotes become males.

twims who originate from one zygote that splits apart very early in development. (also called identical twins) other monozygotic multiple births (such as triplet and quadruplets) can occur as well

twins who are formed when two separate ova are fertilized by two separate sperm at roughly the same time.(also called fraternal twims)

the inability to conceive after at least a year of trying to do so via sexual intercourse

fertilization that takes place outside a woman's body(as in a glass laboratory dish,) the procedure involves mixing sperm with ova that have been surgically removed from the woman's ovary. If the combination produces a zygote, it is inserted into the woman's uterus, where it may implant and develop into a baby

the observable characteristics of a person, including appearance, personality, intelligence, and all other traits.

refuerring to a trait that is influenced by many genes.

referring to a trait that is affected by many factors, both genetic and environmental.

an international effort to map the complete human genetic code. this effort was essentially completed in 2001, though analysis is ongoing.

a gene that has several alleles, each of which contributes to the final phenotype(such as skin color or hegiht)

the interaction of a pair of alleles in such a way that the phenotype reveals the influence of one allele (the dominant gene) more that that of the other(the recessive gene)

reffering to a gene carried on the X chromosome. if a boy inherits an x-linked recessive trait form his mother, he expresses that trait because the Y from his father has no counteracting gene. Gilrs are more likely to be carries of X-linked traits but are less likely to express them.

a statistic that indicated what percentage of the variation in a particular trait within a particular population, in a particular context and era, can be traced to genes.

a condition in which an organism has a mixture of cells, some normal and some with an odd number of chromosomes or a series of missing genes.

a condition in which a person has 47 chromosomes instead of the usual 46, with three rather than two chromosomes at the 21st position. People with down syndrome typically have distinctive characteristics, including unusual facial features, heart abnormalities, and language difficulties(also called trisomy-21)

a genetic disorder in which part of the X chromosome seems to be attached to the rest of it by a very thin string of molecules. The causes is a single gene that has more that 200 repetitions of one triplet.

consultatio and testing by tyrained experts that enable individuals to learn about their genetic heritage, including harmful conditions that they might pass along to any children they may conceive.

a genetic disorder in which a child's body is unable to metabolize an amoni acid called phenylalanie. the resulting buildup of phenylalanine in body fluids causes brain damage, progressive mental retardation, and other symptoms

a general term for the techniques designed to help infertile couples conceive and then sustain a pregnancy