Genetics Ch. 3

The fourth stage of M phase. As anaphase proceeds, half of the chromosomes move to one pole, and the other half move to the other pole.

A form of reproductiopn that does not involve the union of gametes; at the cellular level, a preexisting cell divides to produce two new cells.

Chromosomes that are not sex chromosomes.

The physical process whereby a bacterial cell divides into two daughter cells. During this event, the two daughter cells become divided by the formation of a septum.

A structure in which two pairs of homologous sister chromatids have synapsed (aligned) with each other.

In eukaryotic cells, a series of stages through which a cell progresses in order to divide. The phases are G for growth, S for synthesis (of the genetic material), and M for mitosis. There are two G phases, G1 and G2.

The structure that forms between two daughter plant cells that leads to the separation of the cells by the formation of an intervening cell wall.

A segment of eukaryotic chromosomal DNA that provides an attachment site for the kinetochore.

A cellular structure from which microtubules emanate.

The site where crossing over occurs between two chromosomes. It resembles the Greek Letter chi, X

Following chromosomal replication in eukaryotes, the two copies remain attached to each other in the form of sister chromatids.

Pairs of replicated chromosomes that are attached to each other at the centromere. Sister chromatids are genetically identical to each other.

A theory of Sutton and Boveri, which indicated that the inheritance patterns of traits can be explained by the transmission patterns of chromosomes during gametogenesis and fertilization.

The structures within living cells that contain the genetic material. Genes are pysically located within the structure of chromosomes. Biochemically, chromosomes contain a very long segment of DNA, which is the genetic material, and proteins, which are bound to the Dna and provide it with an organized structure.

A constriction that causes the division of two animal cells during cytokinesis.

The fifth stage of prophase of meiosis I

The fourth stage of prophase of meiosis I

In flowering plants, the female gametophyte that contains an egg cell.

In flowering plants, the material in the seed, which is 3n, that nourishes the developing embryo.

The production of gametes.

the haploid generation of plants

gametes

Describes the single copy of an X-linked gene in the male. A male mammal is said to be hemizygous for X-linked genes.

In a species with two types of sex chromosomes, the heterogametic sex produces two types of gametes. For example, in mammals, the male is the heterogametic sex, because a sperm can contain either an X or a Y chromosome.

Describes a species that produces two morphologically different types of gametes.

A gene on the Y chromosome

In a species with two types of sex chromosomes, the homogametic sex produces only one type of gamete.

One of the chromosomes in a pair of homologous chromosomes.

A photographic representation of all the chromosomes within a cell. It reveals how many chromosomes are found within an actively dividing somatic cell.

A group of cellular proteins that attach to the centromere during meiosis and mitosis.

The series of phases G1, S, and G2, during which a cell spends most of its life.

Describes a species that makes morphologically similar gametes.

The first stage of prophase of meiosis I.

A physical location of a gene within a chromosome.

A form of nuclear division in which the sorting process results in the production of haploid cells from a diploid cell.

The third stage of M phase. The chromosomes align along the center of the spindle apparatus, and the formation of the spindle apparatus is complete.

The plane at which chromosomes align during metaphase.

A type of nuclear division into two nuclei, such that each daughter cell will receive the same complement of chromosomes.

The structure that organizes and separates the chromosomes during M phase of the eukaryotic cell cycle.

A darkly staining region that contains the genetic material of mitochondria, chloroplasts, or bacteria.

the production of egg cells

A large specialized structure within a cell, which is often surrounded by a single or double membrane.

The third stage of prophase of meiosis I

The male gametophyte of flowering plants.

The second phase of M phase. During this phase, the nuclear membrane vesiculates, and the mitotic spindle is completely formed.

The first stage of M phase. The chromosomes have already replicated and begin to condense. The mitotic spindle starts to form.

The inheritance pattern of genes that are found on both the X and Y chromosomes. Even though such genes are located physically on the sex chromosomes, their pattern of inheritance is identical to that of autosomal genes.

A pari of crosses in which the traits of the two parents differ with regard to sex. For example, one cross could be a red-eyed female fly and a white-eyed male fly, and the reciprocal cross would be a red-eyed male fly and a white-eyed female fly.

A point in the G1 phase of the cell cycle that causes a cell to progress to cell division.

A pair of chromosomes that determines sex in a species.

The phenomenon that certain genes are found on one of the two types of sex chromosomes but not both.

The diploid generation of plants

The event in which homologous chromosomes recognize each other and then align themselves along their entire lengths.

A complex of proteins that promote the interconnection between homolgous chromosomes during meiosis.

The fifth stage of M phase. The chromosomes have reached their respective poles and decondense.

An experimental cross between a recessive individual and an individual whose genotype the experimenter wishes to determine.

1. The association among four sister chromatids during meiosis. 2. a group of four fungal spores contained within an ascus.

Genes that are physically located within the X chromosome.

An inheritance pattern in certain species that involves genes that are located only on the X chromosome.

the second stage of prophase of meiosis I.