Biology Exam 3

The Parent individuals from which offspring are derived in studies of in heritance. P stands for parental.

The exchange of segments between chromatids of homologous chromosomes during prophase 1 of meisosis.

Having two identical alleles for a given gene.

A basic principle in biology stating that genes are located in chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns.

Having two different allelles for a given gene

A chromosome not directly involved in determining the sex of an organism; in mammals, for example, any chromosome other than X or y

The microscopically visible site where crossing over has occured between chromatids of homologous chromosomes during prophase 1 of meiosis

The region of a chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. The centromere divides at the onset of anaphase during mitosis and anaphase 11 of meiosis

A diagram used in the study of inheritance to show the results of random fertilization

The creation of genetically distinct offspring by the fusion of two haploid sex cells (gametes: sperm and egg), forming a diploid zygote

With respect to given genes, the number of recombinant progeny from a mating divided by the total number of progeny. Recombinant progent carry combinations of alleles different from that seen in either of the parents as a result of independent assortment of chromosomes and crossing over.

In a sexually reproducing organism, the division of a single diploid cell into four haploid daughter cells. Meiosis and cytokinesis produce haploid gametes from diploid cells in the reproductive organs of the parents

The particular site where a gene is found on a chromosome. homologous chromosomes have corresponding gene loci

The offspring of two parental ( P. generation) individuals. F1 stands for first filial.

character

An alternatative version of a gene

cross

A cyclically operating set of proteins that triggers and coordinates events in the eukaryotic cell cycle

The additive effect of two or more genes on a single phenotypic characteristic.

Material in the cytoplasm of a eukaryotic cell that gives rise to microtubules; important in mitosis and meiosis; functions as a microtubule-organizing center

The third stage of mitosis, beginning when sister chromatids seperate from each other and ending when a complete set of daughter chromosomes has arrived at each of the two poles of the cell

The scientific study of heredity ( inheritance)

An abnormal mass of cells that froms within otherwise normal tissue

Referring to organisms for which sexual reproduction offspring with inherited traits indentical to those of the parents. The organisms are homozygous for the characteristics under consideration.

The production of offspring with gene combinations that differ from that found in either parent

Down syndrome

Treatment for cancer in which drugs are administered to disrupt cell division of the cancer cells

The second stage of mitosis. During metaphase, the centromeres of all the cell's dupicated chromosomes are lined up in imaginary plate equidistant between the poles of the mitotic spindle

Containing two sets of chromosomes ( homologous pairs) in each cell, one set ingerited from each parent; referring to a 2n cell

The phase in the eukaryotic cell cycle when the cell is not actually dividing. During interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase. ______ accounts for 90% of the cel cycle.

A malignant growth or tumor caused by abnormal and uncontrolled cell division.

in a heterozygote, the allele that determines the phenotype with respect to a paticular gene

An abnormal tissue mass that spreads into neighboring tissue and to other parts of the body; a cancerous tumor

The expressed traits of an organism

Treatment for cancer in which parts of the body that have cancerous tumors are exposed to high energy radiation to disrupt cell dicision of the cancer cells

The forth and final stage of mitosis, during which daughter nuclei from at the two poles of a cell. Telophase usually occurs together with cytokinesis

A variant of a character found within a population, such as purple flowers in pea plants

The first sign of cytokinesis during cell division in an animal cel; a shallow groove in the cell surface near the old metaphase plate

A rule stating that the probability of a compound event is the product of the seperate probablities of the independent events

One of the two identical parts of a duplicated chromosome. While joined, two sister chromatids make up one chromosomes