Unit 6 Review
30 Scantron Questions
- Vocabulary Matching
- True or False
- Multiple Choice
1. What does DNA stand for? Deoxyribonucleic Acid
2. What is the function of DNA?
- Stores genetic (hereditary) information
- Controls cell functions
3. Who id’d DNA structure? Watson & Crick in 1953
4. Three parts of nucleotide?
- Phosphate, Deosyribose (sugar), Nitrogen base
- Nitrogen base is different for each nucleotide (different shapes)
5. Pyrimidines: Single ring shape, Thymine and Cytosine
6. Purine: Double ring shape, Adenine and Guanine
7. Complementary Base Pairs
- The two nitrogen bases that bond together
- Purine always bonds with a pyrimidine
- Adenine pairs with Thymine, Guanine pairs with Cytosine
8. What is the structure of DNA?
- Structure - Double helix, two stands of nucleotides connected
- Backbone - sugar and phosphate
- Rungs (sticks out into center of molecule) - nitrogen-base
– The order of bases is the genetic code, order codes for a specific
gene (protein)
9. Parts of the Cell Theory
• All living organisms are made up of one or more cells
• Cells are the basic unit of structure and function in living
organisms
• All cells come from the division of pre-existing cells
10. Cell Division – process where a cell splits (divides) into two cells
11. DNA Replication
• Helicase (enzyme) breaks apart bonds between base pairs. This
separates the left and right strands of the DNA molecule
• DNA polymerase (enzyme) adds complementary base pairs to each
separated strand.
• Makes two new molecules of DNA
12. Can enzymes make mistakes – YES!
• Mutation – change in the order of nucleotides in a molecule of DNA
13. Most common mutations:
- Substitution – wrong nucleotide added
- Addition – extra nucleotide(s) added
- Deletion – nucleotide(s) removed
14. Prokaryotic Cell Division:
- Binary Fission (DNA copied, Cell grows, Cytokinesis)
15. Eukaryotic Cell Division:
- Mitosis or Meiosis then Cytokinesis
16. Main parts of the cell cycle:
- Interphase (G1, S, G2), Division (M phase & Cytokinesis)
17. Interphase:
- G1 (time gap 1)- cell grows & performs daily cellular activities
- S Phase (synthesis) - DNA replication, all DNA is copied (identical
DNA copies (chromatids) are held together at a centromere
- G2 (time gap 2) - cell grows, gets ready to divide, duplicates
organelles
18. DNA transform into a chromosome? How does this happen?
• Prophae
• DNA coils around proteins (histones) during Prophase, this
structure is then called a chromosome
• Chromosomes (in X shape) are actually two identical strands of
DNA (sister chromatids) held together by a centromere
19. when does the nucleus disappear? Prophase
Reappear? Telophase
20. How many times does the cell divide in mitosis? Once
• How many cells are formed? Two Diploids
• How many chromosomes (human cells)? 46 chromosomes
21. What happens during prophase?
• DNA coils up into a chromosome (sister chromatids are attached
by centromere)
• Nucleus and nucleolus disappears
• Centrosomes appear and begin to form spindle fibers
22. What are spindle fibers? Microtubules (proteins)
Where do they form? Around centrosomes
23. What happens during metaphase?
• Chromosomes (sister chromatids) line up in the middle of the cell
• Spindle fibers elongate and attach to the centromere of each
chromosome/chromatid
24. What happens during anaphase?
• Spindle fibers shorten and pull on the centromere
• Centromere breaks and the chromosome’s chromatids are
separated
• Chromatids are pulled to opposite ends of the cell
25. What happens during telophase?
• Nucleus reforms around each grouping of chromatids (2 nuclei
form)
• Chromosome/chromatids unwind back into DNA
• Cell gets ready to split in the middle
26. What is cytokinesis? How is it different in plants & animals?
• Definition – division of the cytoplasm
• Animals – cell membrane splits/pinches down the middle
• Plants – after the cell membrane splits/pinches down the middle,
the plant cell would then form cell plate in the center of the cells
27. How many times does the cell divide in meiosis?
• Twice, Forms Four Cells
• Each cell has 23 chromosomes, Cells known as
Haploid/Gamete/Reproductive Cell
28. What happens in meiosis?
• After completing Interphase (G1, S, G2), the cell would divide
once (Meiosis I). The two cells would then each divide again
(Meiosis II). This produces 4 haploid cells (reproductive cells)
29. How is spermatogenesis different from oogenesis?
• Spermatogenesis - formation of sperm, cytoplasm divides equally
within the two divisions, produces four equal sized cells
• Oogenesis - formation of one egg and three polar bodies,
cytoplasm does not divide equally
Interphase
Back to Interphase
Prophase
Cytokinesis
Telophase
Metaphase
Anaphase