GRADING RUBRIC Unit 4 Test Review 1 Draw

GRADING RUBRIC Unit 4 Test Review

1. Draw a diagram of the Cell Cycle and identify Interphase, G 1, S, G 2, and M phase, and describe what takes place in each phase. Interphase- includes G 1, S, and G 2 G 1 – cell does it job. Growth S – cell replicates it’s DNA G 2 – cell makes sure ready for division (checks DNA, and makes sure there are enough organelles M- mitosis (cell divides)

2. Define the following terms: a. chromosome- strands of chromatin condense and forms 46 chromosomes. Only exist during cell division

b. chromatid- one half of the ‘X-shaped’ chromosome c. sister chromatids- two sister chromatids make up ‘Xshaped chromosome d. centromere- holds chromatids together in the middle

e. autosomes- first 22 pairs of chromosomes f. sex chromosomes- 23 rd pair of chromosomes determine male and female sex characteristic e. homologous chromosomes- each pair (one from dad and one from mom) carry the same genes f. karyotype- picture of chromosomes (homologous pairs matched together. Used to identify genetic disorders.

g. diploid (2 n)- pairs of chromosomes (total of 46). All body (somatic) cells exist as diploid cells h. haploid (n)- half the normal number (23). Gametes (sex cells) contain a haploid number i. chromatin- DNA exists in unwound stands of DNA. Condenses to chromosomes for cell division j. fertilization- the joining of sperm and egg

k. zygote- the fertilized egg l. mutation- any change in an organisms DNA. May alter the function of DNA m. monomer- the individual building blocks of organic molecules. (e. g. Glucose, amino acids, nucleotides) n. polymer- the larger organic compounds built with monomers. (e. g. Nucleotides bonded together form nucleic acids)

o. eukaryote- Cells that contain a nucleus and membrane bound organelles (e. g. plant and animal cells) p. prokaryote- cells that do NOT contain a nucleus or membrane organelles. (e. g. bacteria)

3. Describe and diagram the process of Mitosis and include the following terms: Somatic/Body cells, diploid, chromosomes, centrosomes, spindle fibers, prophase, metaphase, anaphase, telophase, cytokinesis, genetically identical daughter cells. Diploid somatic cells divide by mitosis. After DNA replicated in S-stage of cell cycle, cell goes through PMAT. Spindle fibers made by centrosomes attach to chromosomes and pull chromatids apart to opposite sides of cell. Cell finally divides in half by cytokinesis.

4. Describe and diagram the process of Meiosis and include the following terms: Germ cells, diploid (2 n), haploid (n), gametes, Meiosis II, genetically unique egg and sperm cells. Germ cells (diploid-2 n) in ovaries and testes divide twice (Meiosis I and II) producing 4 genetically unique egg and sperms cells (haploid-n)

5. What contribution did Griffith, Avery, and Hershey & Chase provide concerning a cell’s genetic material? They provided evidence that DNA was the ‘transforming factor’ (cell’s genetic material)

6. What contribution did Erwin Chargaff provide that helped determine the structure of the DNA molecule? He discovered the ratios of nitrogen bases. A = T and C = G (Chargaff’s Rule). Helped Watson Crick determine DNA structure (A’s bonded to T’s and C’s bonded to G’s)

7. What contribution did Rosalind Franklin and Maurice Wilkins provide to Watson and Crick concerning the physical structure (shape) of the DNA molecule? Their photographic images showed that DNA is a helical molecule

8. What contribution did Watson and Crick make concerning DNA? Using work of others, they created 3 -D model of DNA molecule and published work in 1953.

9. Describe and diagram the process of DNA replication and include the following terms: complementary bases, enzymes, original strand, new strand, adenine, guanine, cytosine, and thymine. Hydrogen bonds break (enzymes) and DNA ‘unzips’ exposing bases. New bases bond to complementary bases producing two identical molecules of DNA, each with one original strand one new strand

10. Describe why the surface area to volume ratio helps determine when a cell needs to divide. As a cell grows it’s surface area grows slower than volume. This creates problems with cell trying to get materials in and out of the cell efficiently.

11. Describe how cancerous cells differ from normal cells and include the following terms: mutation, benign, malignant, tumor, cell growth. Uncontrolled cell growth. Mutations cause change in DNA causing cells to continue to grow creating tumors. Can be benign (does not spread) or malignant (spreads)

12. What are telomeres and how does it affect the aging of cells? ‘Caps’ on ends of DNA strands protect DNA during cell division. Get shorter with age.

13. What is a nucleotide and how does one nucleotide vary from another? Nucleotides are the monomers of nucleic acids (DNA and RNA). Each differs by having a different nitrogen base (A, T, C, G)

14. What is crossing-over, where and when does it occur, and how does it affect the genetic diversity of gametes produced during meiosis? Include a diagram. Homologous chromosomes ‘legs’ or ‘arms’ cross over each other during Meiosis I and exchange parts of themselves with neighboring chromosome creating increased genetic diversity.

15. What is the significance of DNA being a two-stranded molecule? I allows DNA to be easily replicated ensuring exact copy will be made

16. What is binary fission and how is it similar and different from mitosis? Binary fission in prokaryotes and mitosis in eukaryotes. Both produce identical daughter cells with identical DNA. Genetically unique cells (gametes) with half the amount of DNA identical to parent cell

17. DNA is said to control all of the cells structure and function. How does it accomplish this? DNA contains 22, 000 genes that each carry a code to produce one protein.

18. What would result if the genetic code in DNA used to produce a particular protein was mutated and altered? When the sequence of nucleotides is changed it will alter the protein produced. This will alter the proteins shape and its properties.

19. If one side of a DNA molecule contains the following sequence of nucleotides, GCCATACAT, the complementary sequence on the other side would be: GCCATACAT CGGTATGTA A=T G=C

20. What are the advantages and disadvantages of asexual and sexual reproduction? Asexual: very effective in environments that do not change. Produce identical offspring. Sexual: very effective in changing environments. Produce genetically unique offspring.