SCIENCE

Posted: November 12, 2010

SCIENCE TEST CHAPTER 5 THURSDAY, NOVEMBER 18        Chapter 5 Review   Questions 2 – 7 on page 173   Go over your Questions and Vocabulary   Also the following Questions:   1.   Structures of both plant and animal cells along with their definition. 2.   Differences between cell wall and cell membrane. 3.   The different stages of mitosis and what happens in interphase. 4.   Why do cells divide faster in an embryo then in adults? 5.   What are the differences between asexual and sexual reproduction? 6.   Name 5 types of asexual reproduction and describe two types.     Review Answers   Page 172   2. A) Plant Cells = A and B,        Animal Cells = C and D     B) A = Metaphase          B = Telophase          C = Anaphase          D = Telophase   3. Cells alternate between stages (phases) of dividing and not dividing. The sequence of events from one cell division to another is called the cell cycle. For most cells, cell division marks only a small part of this cycle.   4. The stage between division, called interphase, is marked by rapid growth and the duplication of genetic material, followed by another period of growth and preparation of further divisions.   5. Plant – telophase -> plate forms     Animal – telophase -> cytoplasm pinches off between dividing cells   6. Cells from the brain show little capacity to regenerate. Skin cells are replaced after a sunburn. Calluses form on the hands quickly after gardening.   7. If the genetic material did not duplicate, the cell would not be able to divide again. Single-stranded chromosomes move to the opposite poles of a cell during metaphase. Once the cell has undergone cytokinesis, these single-stranded chromosomes must once again become double-stranded for mitosis to occur.   Questions From Review   See definitions on organelles. Cell wall is rigid, made of cellulose, and found outside of the cell membrane in plant cells. Cell membrane is fluid, allows materials into and out of the cell, and is found in both plant and animal cells. See notes on mitosis. Phases are prophase, metaphase, anaphase, telophase, and cytokinesis. Interphase is in between all of these phases. Embryos are young and cells are dividing quickly as the embryo has to reach a certain size before it is born. The embryo is also still growing. Adults have finished growing therefore their cells will only divide to replace damaged or dead cells. Asexual reproduction produces a clone of the organism/cell. Only need one individual to do this. Mitosis is an example of asexual reproduction. Sexual reproduction requires specialized cells (usually a sperm and egg cell) from two parents to produce a new, unique individual. Types of asexual reproduction are: Budding, Spore Formation, Fragmentation, Binary Fission, and Vegetative Reproduction. See pages 160 – 161 for more info.