Cell Division: Mitosis and Meiosis

Cell division in which the nucleus divides into nuclei containing the same number of chromosomes. Two daughter cells identical to the parent. Takes 2 to 4 hours and is constant. Segregation of sister chromatids. Growth of the embryo and in somatic cells capable of cell division. Processes 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.

<p>The period between cell division, which includes G1, S, and G2 phases.</p> Signup and view all the answers

<p>A checkpoint that ensures all chromosomes are properly attached to the spindle fibers before they can segregate.</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>Cells that have left the cell cycle and are not dividing.</p> Signup and view all the answers

<p>Cell size and DNA replication.</p> Signup and view all the answers

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

<p>The first stage in interphase, during which cellular growth and development take place. Cell size increases and checks to see if the cell is ready for division.</p> Signup and view all the answers

<p>The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated. Two sister chromatids per chromosome (2n; 4d). DNA synthesis/DNA replication. Enzymes of replication are active. DNA proofreading activity of DNA polymerase is active.</p> Signup and view all the answers

<p>Mitosis and cytokinesis.</p> Signup and view all the answers

<p>Two daughter cells each with 2n; 2d.</p> Signup and view all the answers

<p>If there is something wrong with the cell, it is a checkpoint that regulates cells through the cell cycle. Only two in the human body.</p> Signup and view all the answers

<p>May cause apoptosis if the damage is extensive</p> Signup and view all the answers

<p>Allows 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 are present.</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 of these are created during the S subphase of interphase.</p> Signup and view all the answers

<p>After fertilization (embryogenesis). The sister chromatids of a chromosome 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>Forms four gametes, each has 23 chromosomes. One of each kind of autosome and either an X or a Y (23X or 23Y).</p> Signup and view all the answers

<p>Results in the formation of one ovum (23X) and polar bodies.</p> Signup and view all the answers

<p>Formation of sperm.</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). (n; 2d)</p> Signup and view all the answers

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

<p>Formation of haploid gametes (n)</p> Signup and view all the answers

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

<p>Sister chromatids fail to separate. Result in n, n, n+1, n-1.</p> Signup and view all the answers

<p>Increased maternal age increases meiotic nondisjunction risk. May occur in meiosis I or II. Aneuploidy. Karyotype shows ALL cells with an abnormal karyotype. Differentiated from mitotic nondisjunction.</p> Signup and view all the answers

<p>Chromosomal abnormality consisting of the absence of one chromosome from the normal diploid number. Only compatible with 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>Inheritance of both chromosome copies from the father. No mom copy.</p> Signup and view all the answers

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

<p>Transcriptionally silenced if it was transmitted from the mother; paternally inherited allele is expressed.</p> Signup and view all the answers

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

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

<p>The X and Y chromosomes fail to separate properly during meiosis I. This will result in sperm cells with either two copies of the X chromosome, two copies of the Y chromosome, or no sex chromosomes. The other sperm cells will have one copy of the sex chromosome.</p> Signup and view all the answers

<p>The resulting zygote can have either an extra X chromosome or an extra Y chromosome, or may have an X or a Y chromosome missing. This can lead to conditions like Klinefelter Syndrome which is XXY or Turner's syndrome, which is XO.</p> Signup and view all the answers

<p>This could lead to the formation of an egg cell with two X chromosomes or an egg cell with no X chromosomes.</p> Signup and view all the answers

<p>Four.</p> Signup and view all the answers

<p>One egg and three polar bodies.</p> Signup and view all the answers

<p>Mitotic divisions of cells occur at different times in males and females. All mitotic divisions for females are completed by birth.</p> Signup and view all the answers

<p>At birth, the primary oocytes are arrested at prophase 1 of meiosis 1 (frozen eggs). Meiosis II is only completed after fertilization.</p> Signup and view all the answers

<p>Male gametogenesis, or spermatogenesis, commences at puberty. There are 30 to 500 mitotic divisions in gamete formation, producing four spermatids per meiosis. A male produces 100 to 200 million sperm cells per ejaculate.</p> Signup and view all the answers

<p>Early embryonic life, 20 to 30 mitotic divisions in gamete formation. One ovum (polar bodies) per meiosis for gamete production. One ovum per menstrual cycle for gamete production.</p> Signup and view all the answers

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

<p>Underdeveloped sex organs, breast development, large hands, and long arms and legs. Extra X chromosome.</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