3. What is a sister chromatid? A centromere? A kinetochore?
4. What is the goal of mitotic cell division? 5. Give a brief overview of chromosome condensation. What is the function of the histone proteins? When do chromosomes condense? 6. List the 5 phases of mitosis (as discussed in class). For each, give a brief description of the location & structure of the chromosomes, the location of centrosomes (MTOCs), and the structure of the spindle. 1. Prophase : chromosomes consist of 2 sister chromatids, starting to condense, found in nucleus. Duplicated centrosomes starting to move apart from one another as spindle begins to form between 2. Prometaphase: replicated chromosomes fully condensed with kinetochores at centrosomes. Nuclear envelope fragmented, so chromosomes in cytoplasm.Duplicated centrosomes at opposite ends of cell, spindle almost fully formed, microtubules begin interacting with ‘free chromsomes’ 3. Metaphase : replicated chromosomes each attached to microtubules from both centrosomes are found on ‘metaphase plate’ – midway between centrosomes. Centrosomes at opposite ends of cell; spindle fully formed between them. Kinetochore microtubules attached to kinetochores, nonkinetochore microtubules are overlapping. 4. Anaphase : Sister chromatids separated are now individual chromosomes – still attached via kinetochores to spindle microtubules are being moved to centrosomes.Centrosomes at opposite ends of cell are moving away from one another due to the action of overlapping nonkinetochore microtubules.
You've reached the end of your free preview.
Want to read all 31 pages?