Reading+Questions+SLS

Chapter 18 Patterns of Chromosome Inheritance.

pp.378-379 Chromosomes and the Cell Cycle 1. What is interphase and what are the three stages of interphase. Describe them in detail. This is when the organelles carry out their usual functions, this is where they also prepare to divide. They grow into organelles and chromatin double, and DNA synthesis occurs and also DNA synthesis allows for stages. G1, S, and G2.

2. Define Mitosis and Cytokinesis and Apoptosis. M: A type of nuclear division. C: Division of the cytoplasm A: Programmed cell death

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. Karyotype: a numbered chromatid pairs.

pp. 380 Obtaining Fetal Chromosomes 1. Why would it be important to obtain fetal chromosomes? Because it allows you to be able to do karyotyping to tell whether the child would have a disorder, or in other words, a wrong pair of chromatids.

2. Describe the two ways to obtain fetal chromosomes. Chorionic villi sampling: 8-12 week pregnancy. obtaining of fetal chromosomes through villi by suction of tube. There is agreater risk of accidental abortion this way. Amniocentesis: 15-17 week of pregnancy: needle passed through abdominal wall to retrieve amniotic fluid and 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 it is a single chromosome, and after duplication it is attached with sister chromosome.

2. What does the cell use to pull the duplicated chromosomes apart? The spindle separates the chromosomes during mitosis.

3. Describe the important parts of each phase of mitosis: Prophase, Metaphase, Anaphase, and Telophase. P: nucleus disappears, duplication of chromosomes, centrosomes begin separating and spindles start forming. M: chromosomes align. spindles attach. A: separation occurs. "daughter" T: nucleuses appear and cells separate.

4. How is the cytoplasm divided between the daughter cells following mitosis? They form cleavage around cell and then pinch it apart, and secondly they create plasma membrane for each cell.

5. When do human body cells go through mitosis normally? They begin when fertilized eggs start dividing.

6. What is a result of mitosis that is not in control? 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, haploid chromosome number, diploid chromosome number. You may need to look these up. Gamete: A mature sexual reproductive cell, as a sperm or egg, that unites with another cell to form a new organism Haploid Chromosome Number: A cell having only one complete set of chromosomes, ordinarily half the normal diploid number Diploid Chromosome Number: A cell having double the basic haploid number of chromosomes.

2. Which cells of your body have a diploid number of chromosomes? Those cells that have gone through meiosis, and those that are found in reproductive cells.

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 is to produce gametes and keep the chromosome level steady.

5. Which cells of your body have a haploid number of chromosomes? All tissue cells.

6. Which process uses meiosis: sexual or asexual reproduction? Why?

7. Which takes less time: sexual or asexual reproduction? Why? Asexual reproduction takes less time, this is because sexual reproduction involves courtship and everything that follows.

8. Why is sexual reproduction more complicated then asexual reproduction? It involves finding a mate and courtship and energy.

9. How do the benefits of sexual reproduction outweigh the costs? Genetic recombination.