Mitosis and Meiosis Quiz

Sister Chromatid

identical halves of a duplicated parent chromosome that are held together by a centromere. identical tightly coiled halves of a duplicated chromosome

Chromatin

loose, uncondensed, long strands of DNA found in the eukaryotic cell nucleus; condense to form chromosomes. fills the nucleus during most of the cell cycle.

Centromere

region of chromosome that holds two sister chromatids together during mitosis

Cell division

the process by which a cell divides into two new daughter cells

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Cell Cycle

series of events that cells go through as they grow and divide. Interphase + Mitosis

G1

Growth phase 1; cell grows and makes proteins.

cellular contents excluding the chromosomes, are duplicated

S phase

DNA Synthesis

Cell continues to grow as it copies its chromosomes

Each of the 46 chromosomes are duplicated by the cell

G2

Gap 2

Cell grows more as it completes preparations of cell division. cell '“Double checks” the duplicated chromosomes for error, making any needed repair

Mitotic Phase

Stage of the cell cycle where the cell is actively dividing.

Cytokinesis

Stage of cell cycle where cytoplasm divides.

Interphase

period of the cell cycle during which the nucleus is NOT undergoing division, typically occurring between mitotic or meiotic divisions

• includes g1, g2, and 2 phase

Prophase (Mitosis)

1. chromatin condenses into chromosomes becomes visible

2. nuclear envelope breaks down

3. centrosomes begin to move to opposite sides

4. centrioles form and move toward opposite ends of the cell, the poles

5. spindle fibers from each centriole attach to each sister chromatid at the kinetochore

Centrosome

cellular structure involved in the process of cell division. Duplicates and then, as division begins, two centrosomes move to opposite ends of the cell two centrioles. centrosomes organize the microtubules as they pull APART.

Mitotic Spindle

An assemblage of microtubules and associated proteins that is involved in the movements of chromosomes during mitosis.

Spindle microtubules/fibers

The filaments are responsible for moving chromosomes during cell division.

• fibers that attach to chromosomes and move the chromosomes by pulling homologous chromosomes opposite directions and pushing the poles apart

Kinetichore

a specialized region on the centromere that links each sister chromatid to the mitotic spindle

Metaphase

second phase of mitosis, during which the chromosomes line up across the center of the metaphase plate

Anaphase

Begins when the two centromeres of each chromosome come apart, separating the sister chromatids. Elongates the cell.

Telophase

the final stage of mitosis or meiosis, during which a nuclear membrane forms around each set of new chromosomes

Cleavage Furrow

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

Cell Plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

Cell Cycle Control System

A cyclically operating set of molecules in the cell that triggers and coordinates key events in the cell cycle.

Tumor

an abnormal new mass of tissue that serves no purpose (caused by overproduction and buildup of cells)

Somatic Cell

any of the cells of a plant or animal except the reproductive cells

Sex chromosomes

one of the 23 pairs of chromosomes in the human, contains genes that will determine the sex of the individual

Autosomes

chromosomes that are not directly involved in determining the sex of an individual

Diploid

(genetics) an organism or cell having two sets of chromosomes or twice the haploid number

Haploid

(genetics) an organism or cell having only one complete set of chromosomes

Gametes

sex cells

Fertilization

creation by the physical union of male and female gametes

Zygote

fertilized egg or the product of two joined gametes

Meiosis

(genetics) cell division that produces reproductive cells in sexually reproducing organisms

Prophase 1 (Meiosis)

DNA coils tightly into chromosomes and spindle fibers appear; the nucleolus and nuclear membrane disassemble and every chromosomes lines up next to its homologue. During this process, the chromosomes within a homologous pair twist around one another. Crossing-over, or the exchange of genetic material between maternal and paternal chromosomes may occur.

Metaphase 1 (Meiosis)

pairs of homologous chromosomes, line up randomly along the midline of the dividing cell. Spindle fibers from one pole attach to the centromere of one homologous chromosome and spindle fibers from the opposite pole attach to the other chromosome of the pair.

Homologous Chromosome

one of a matching pair of chromosomes, one inherited from each parent

Homologs

Matching Chromosomes that are similar but not identical

Anaphase 1 (Meiosis)

homologous chromosomes seperate

Telophase 1 (Meiosis)

Chromosomes reach the opposite ends of the cell and cytokinesis begins.

Cytokinesis (Meiosis)

The cell splits into 2 daughter cells with 2 chromatids in each. The chromosomes are different from each other and from the parent diploid cell because of the crossing over that occurred in Prophase I.

Meiosis II

The second division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the chromosome number of the original cell.

Tetrad

structure containing 4 chromatids that forms during meiosis

Crossing over

the interchange of sections between pairing homologous chromosomes during the prophase of meiosis (reorganization)

karyotype

A picture of all the chromosomes in a cell arranged in pairs

nondisjunction

meiosis in which there is a failure of paired homologous chromosomes to separate

Centriole

1. role in organizing microtubules that serve as the cell’s skeletal system.

2. Help determine the locations of the nucleus.

3. Made up of microtubules

4. Centrioles go to opposite ends of the nucleus

5. mainly in animals

kinetochores

a specialized structure on the centromere to which the microtubular spindle fibers attach during mitosis and meiosis

prometaphase

transitional stage in mitosis ( cell division) between prophase and metaphase.

Nuclear envelope breaks down, allowing spindle fibers to enter the nucleus and attach to the chromosomes at their kinetochores, initiating chromosome movement towards the cell’s center.

follows prophase.