Cell Division and Genetics Overview

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes. Two daughter cells identical to the parent. It takes 2 to 4 hours and is constant. Segregation of sister chromatids. Growth of the embryo and in somatic cells capable of cell division. The stages include prophase, metaphase, anaphase, telophase, and cytokinesis.

An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other.

The time from the birth of a new somatic cell until it divides into two new daughter cells. It includes interphase (the period between cell division) and mitosis (the period of actual cell division).

<p>The time between cell division. It is characterized by three sub-phases: G1, S, and G2.</p> Signup and view all the answers

<p>A checkpoint that ensures that all chromosomes are properly attached to the mitotic spindle before the cell proceeds to anaphase.</p> Signup and view all the answers

<p>A checkpoint that checks for cell size, nutrients, growth factors, and DNA damage.</p> Signup and view all the answers

<p>G0</p> Signup and view all the answers

<p>G1, S, G2, M</p> Signup and view all the answers

<p>A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.</p> Signup and view all the answers

<p>There are two daughter cells with 2n;2d.</p> Signup and view all the answers

<p>If something is wrong with the cell, p53 is a checkpoint that regulates cells through the cell cycle. There are only two p53 proteins in the human body.</p> Signup and view all the answers

<ol> <li>Cell cycle arrest or activation of the G1-S checkpoint. 2. Activation of DNA repair systems. 3. If damage is extensive, it may cause apoptosis.</li> </ol> Signup and view all the answers

<p>It allows the proliferation of cells with DNA damage. Uncontrolled proliferation can lead to tumor development.</p> Signup and view all the answers

<p>The beginning of mitosis. The nuclear envelope dissolves. The mitotic spindle forms (tubulin). Chromosomes condense and become visible. Chromosomes bind to the spindle. Homologous chromosomes and sister chromatids.</p> Signup and view all the answers

<p>Chromosomes that have the same sequence of genes and the same structure.</p> Signup and view all the answers

<p>Identical copies of a chromosome. Full sets are created during the S subphase of interphase.</p> Signup and view all the answers

<p>After fertilization (embryogenesis), sister chromatids fail to separate (aneuploidy in daughter cells). The fetus is a mosaic. Karyotype shows a mixture of cells; normal cells; and cells with aneuploidy.</p> Signup and view all the answers

<p>Normal karyotype and cells with trisomy 21</p> Signup and view all the answers

<p>A condition in which cells within the same person have a different genetic makeup. Karyotype shows a mixture of normal and aneuploidy cells. Confined germline mosaic.</p> Signup and view all the answers

<p>It forms four gametes, each has 23 chromosomes. One of each kind of autosome and either an X or Y (23X or 23Y).</p> Signup and view all the answers

<p>The formation of sperm cells.</p> Signup and view all the answers

<p>The production, growth, and maturation of an egg, or ovum.</p> Signup and view all the answers

<p>Homologous chromosomes separate (reduction division) resulting in n;2d.</p> Signup and view all the answers

<p>Genetic variation in offspring.</p> Signup and view all the answers

<ol> <li>Formation of a haploid gamete (n). After fertilization, the diploid set of chromosomes is in the zygote; the second set of chromosomes is derived from the other parent. 2. Genetic recombination and diversity (gametes are not alike). Recombination/crossover during prophase-I of meiosis. Random segregation of homologous chromosomes during anaphase-I.</li> </ol> Signup and view all the answers

<p>Homologous chromosomes fail to separate resulting in n+1, n+1, n-1, n-1.</p> Signup and view all the answers

<p>Increased maternal age increases the risk of meiotic non-disjunction. It may occur in meiosis I or II. Aneuploidy occurs. Karyotype shows ALL cells with abnormal karyotype. It is differentiated from mitotic non-disjunction.</p> Signup and view all the answers

<p>Chromosomal abnormality consisting of the absence of one chromosome from the normal diploid number. It is only compatible with an X (Turner syndrome).</p> Signup and view all the answers

<p>A chromosomal disorder in females in which either an X chromosome is missing, making the person XO instead of XX, or part of one X chromosome is deleted.</p> Signup and view all the answers

<p>One copy is derived from the dad and a second copy is derived from the mom.</p> Signup and view all the answers

<p>Inheritance of both chromosome copies from the mother. No dad copy.</p> Signup and view all the answers

<p>It is transcriptionally silenced if it was transmitted from the father.</p> Signup and view all the answers

<p>Prader-Willi syndrome, Angelman syndrome, and Marfan syndrome.</p> Signup and view all the answers

<p>Methylated, it's silenced.</p> Signup and view all the answers

<p>X0, XXY, XYY, or OY.</p> Signup and view all the answers

<p>XXY, XXX, or XO.</p> Signup and view all the answers

<p>Four sperm cells per round.</p> Signup and view all the answers

<p>Mitotic division of cells occur at different times in males and females. Females have undergone all mitotic division by birth.</p> Signup and view all the answers

<p>At birth, the primary oocytes are arrested at prophase I of meiosis I. Meiosis II is only completed after fertilization.</p> Signup and view all the answers

<p>It commences at puberty. There are 30 to 500 mitoses in gamete formation, 4 spermatids per meiosis, and 100 to 200 million per ejaculate of gamete production.</p> Signup and view all the answers

<p>Higher risk of non-disjunction in meiotic divisions I or II in a female greater than 35 years old, resulting in a higher risk of trisomy in the fetus. The higher the paternal age, the greater the risk of developing new dominant single gene mutations (replication error).</p> Signup and view all the answers

<p>It is characterized by underdeveloped sex organs, breast development, large hands, and long arms and legs. Extra X chromosome (XXY instead of XY).</p> Signup and view all the answers

<p>There are 46 chromosomes and 92 sister chromatids.</p> Signup and view all the answers

<p>Each cell has 23 chromosomes and 46 sister chromatids.</p> Signup and view all the answers

<p>There are 23 chromosomes and 23 chromatids.</p> Signup and view all the answers

cell division in which the nucleus divides into nuclei containing the same number of chromosomes. Two daughter cells identical to the parent. 2 to 4 hours and is constant. Segregation of sister chromatids. Growth of embryo and in somatic cells capable of cell division. Prophase, metaphase, anaphase, telophase, and cytokinesis.

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.

An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other.

sequence of events by which a cell duplicates its genome, synthesizes the necessary proteins and organelles and divides itself to produce two daughter cells.

The time between cell division where the cell grows and prepares for division.

A checkpoint that checks for chromosome attachment to the spindle.

A checkpoint that checks for cell size, nutrients, growth factors, and DNA damage.

A non-dividing state occupied by cells that have left the cell cycle. It can sometimes be reversible.

A checkpoint that checks for cell size and DNA replication.

The order of the stages of interphase: G1, S, G2, M

The first stage in interphase, during which cellular growth and development takes place. The cell increases in size and checks whether it is ready for division.

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. Two sister chromatids per chromosome are formed (2n; 4d). DNA synthesis/DNA replication. Enzymes of replication are active. DNA proofreading activity of DNA polymerase is active.

The second gap phase in interphase. The cell prepares for division, checks for DNA replication errors. The cell and cytosol size increase. Post-replication DNA repair mechanisms are active.

Includes mitosis and cytokinesis.

There are two daughter cells, each with the same number of chromosomes as the parent cell.

A protein that acts as a tumor suppressor by regulating cells through the cell cycle.

1.) Cell cycle arrest or activation of the G1-S checkpoint. 2.) Activates DNA repair systems. 3.) If damage is extensive, may cause apoptosis.

Allows proliferation of cells with DNA damage. Uncontrolled proliferation can lead to tumor development.

The first stage of mitosis. The nuclear envelope dissolves. The mitotic spindle forms (tubulin). Chromosomes condense and become visible. Chromosomes bind to the spindle. Homologous chromosomes and sister chromatids.

Chromosomes that have the same sequence of genes and the same structure.

Identical copies of a chromosome; full sets of these are created during the S subphase of interphase.

Chromosomes condense and are maximally visible. They align in the middle of the cell. Can be visualized by karyotyping. Microtubules attach to centromere kinetochores.

Sister chromatids move to the centrioles. Separation of sister chromatids. Non-disjunction during anaphase is mitotic non-disjunction.

Sister chromatids move to opposite poles. The nuclear envelope starts forming. Chromosomes become less condensed. Two new daughter cells (cytokinesis). Daughter cells have the same genetic composition as the parent cell (2n; 46 chromosomes; 23 pairs of chromosomes; 2d).

Occurs after fertilization. Sister chromatids of a chromosome fail to separate, resulting in aneuploidy in daughter cells. The fetus is mosaic. Karyotype shows a mixture of cells; normal cells and cells with aneuploidy.

Results in normal karyotype and cells with trisomy 21 (Down Syndrome)

A condition in which an individual has three number 21 chromosomes, resulting in Down syndrome.

A condition in which cells within the same person have a different genetic makeup. Karyotype shows a mixture of normal and aneuploidy cells. Confined germline mosaic.

Forms four gametes, each has 23 chromosomes. One of each kind of autosome and either an X or a Y (23X or 23Y).

Results in the formation of one ovum (23X) and polar bodies.

Formation of sperm.

The production, growth, and maturation of an egg, or ovum.