Chromosomes+WG

1. What is interphase and what are the three stages of interphase. Interphase is the time when the organelles carry on their usual functions. The cells also get ready to divide. It grows larger, the number of organelles doubles, ad the amount of chromatin doubles as DNA synthesis occurs. 2. Define Mitosis and Cytokinesis and Apoptosis. Cytokinesis is the division of the cytoplasm, and apoptosis is occurs to do away with any cells that are dividing when they shouldn’t. 3. Insert a picture of the "cell cycle". Label it as: The cell cycle. 4. Insert a picture of a human chromosome "karyotype". Label it as karyotype and define karyotype. A karyotype tells us a lot about a body cell. pp. 380 Obtaining Fetal Chromosomes 1. Why would it be important to obtain fetal chromosomes? Obtaining fetal chromosomes are important because if they are not cared for, the fetus will have a great chance of Down syndrome. 2. Describe the two ways to obtain fetal chromosomes. Taking a suction tuve to remove cells from the chorion. Another way is using a long needle to withdraw amniotic fluid containing fetal cells. 3. Insert a picture of a drawing of aminiocentesis. Label it as amniocentesis. pp.381-384 Mitosis 1. Describe the structure of a chromosome before duplication and after duplication. Before duplication the cell is called a parent cell. After duplication is called a daughter cell. 2. What does the cell use to pull the duplicated chromosomes apart? The spindle separates the chromosomes apart. 3. Describe the important parts of each phase of mitosis: Prophase: it indicates that the cell is about to divide. The centrososmes outside the nucleus have duplicated, and they begin moving away from one another toward opposite ends of the nucleus. Spindle fibers appear between the separating centrosomes. Metaphase: during metaphase the nucleur envelope is fragmented, and the spindle occupies the region formerly occupied by the nucleus Anaphase: the centromeres uniting the sister chromatids divide. Then the sister chromatids separate, becoming chromosomes that move toward opposite poles of the spindle. Telophase: it begins when the chromosomes arrive at the poles. During telophase, the chromosomes become indistinct chromatin again. The spindle disappears the nuclear envelope components reassemble in each cell. 4. How is the cytoplasm divided between the daughter cells following mitosis? The cytoplasm creates cleavage around the cell and then it tears apart, and it creates a plasma membrane for each cell. 5. When do human body cells go through mitosis normally? Normal human body cells go through mitosis 6. What is a result of mitosis that is not in control? When mitosis is not controled Give an example of what can occur. 7. Insert a picture that includes each of the phases of mitosis in real cell photographs. Make sure the phases are labeled.

Meiosis see p. 389 1. Define gamete. Gametes are sex cells, sperm, and eggs. Haploid chromosome number is a cell that has only one complete set of chromosomes.Diploid chromosome number is a cell that has double the basic haploid number of chromosomes. 2. Which cells of your body have a diploid number of chromosomes? The ones that had gone through meisois. 3. Which process makes cells with a diploid number of chromosomes? Meiosis 4. What is the purpose of meiosis? (see page 389) the purpose of meiosis has to do with sexual reproduction. The purpose is to ensure that the next generation if individuals will have the diploid number of chromosomes from each parent. 5. Which cells of your body have a haploid number of chromosomes? Every tissue cells 6. Which process uses meiosis: sexual or asexual reproduction? Why? Asexually, because one parent has to produce identical offspring. 7. Which takes less time: sexual or asexual reproduction? Why? Sexual reproduction takes less time, because the sperm has to work asexually. 8. Why is sexual reproduction more complicated then asexual reproduction? It is more complicating because it has more steps and you have to find a mate. 9. How do the benefits of sexual reproduction outweigh the costs? It is a better way to produce life, and the faster way to give birth to a very healthy baby, without the risk of having an unhealthy baby.