Thursday, September 29, 2011

DNA, Mitosis and Meiosis Review Quetions

DNA Review Questions

1. Describe the structure of the DNA molecule

2. If the sequence of bases on one stand of the molecule is AAC TGC CCG, what is the sequence on the complementary strand?

3. During DNA replication, what enzyme breaks the hydrogen bonds between the base pairs, and what enzyme matches up nucleotides to the existing ones on the parent strand of DNA?

4. Why is this type of replication called Semi Conservative?

5. How is RNA different from DNA?

6. The production of messenger RNA from DNA is called ________, and this happens in the __________ of the cell.

7. The parts of the mRNA molecules which are edited out before RNA reaches the cytoplasm are called __________

8. mRNA gets a cap and a tail prior to being read by the ribosome. What is the function of the cap and tail?

9. If the DNA strand being copied had this sequence: ACT GGC ATA CTA what would the sequence of the mRNA be?

10. The function of transfer RNA is ?

11. What is the name of the enzyme that produces RNA from DNA?

12. If the sequence of DNA is the same in your body cells, why are all cells not the same?

13. The DNA in you, an earthworm, and a fungus is the same. So why are you a human and not an earthworm?

14. What is an anti-codon and where is it found?

15. The protein synthesis process that occurs at the ribosome is called _____________

16. What is a stop codon, and what happens when one is read in the ribosome?

Genetic Engineering

1. What are restriction enzymes?
2. What kind of cells have restriction enzymes, and what is the purpose of these enzymes in the cell?
3. What is a plasmid?
4. How are plasmids used in genetic engineering?
5. Why does human DNA work in a bacterial cell?
6. What is gene therapy?
7. How are small fragments of DNA separated during the DNA fingerprinting process?
8. What benefits are there to inserting a human gene into a bacterium? What possible problems could arise from genetically engineered organisms being released into the wild?

Mitosis and Meiosis Review

1. If a cell has 8 chromosomes and does mitosis, how many cells will be made, and how many chromosomes will each cell have?

2. If a cell has 8 chromosomes and does meiosis to make sperm cells, how many cells will be made, and how many chromosomes will each cell have?

3. Mitosis creates cells which are ________, while meiosis makes cells which are _____.

4. What are homologous chromosomes?

5. What are sister chromatids?

6. What is crossing over, and during which process, (mitosis or meiosis) does it occur?

7. Why is crossing over important?

8. During __________ of mitosis sister chromatids separate.

9. During _________ of meiosis homologous pairs of chromosomes separate, but during ____________ of meiosis sister chromatids separate.

10. In meiosis, typically four sperm cells are made, but meiosis only makes one large egg cell. Why?

Monday, September 26, 2011

Joshua Tree National Park

Over the weekend I took a class on the insects and other arthropods of the Morongo Basin. Much of the class was held at Joshua Tree National Park, but we also visited the Morongo Preserve and the Coachella Valley Preserve.
Along the trail to Barker Dam we came across fresh bighorn sheep scat and tracks, but where are the sheep?




There they are, way up on the rocks high above the dam. We ended up seeing two ewes and a ram .


These acorns are the fruit of the scrub oak trees we saw along the trail.



If the acorns are the fruit then what is this?

This is a gall. Small insects, usually small wasps lay an egg on the tree, and inject chemicals as well that cause the plant to create a gall. The gall provides a house for the larval insect and some food as the larva develops.

This is a gall on a creosote shrub. Many plants make galls in response to insects laying eggs on their stems or leaves.


These dark lines along the stems often appear on more mature creosote shrubs. They are made by a type of scale insect. Native Americans would scrape the sticky secretion and use it as a glue.

This beautiful wasp (Scolia dubia) was getting nectar from the flowers.
This is a Mormon metal mark butterfly on a California buckwheat which is the food plant for its larva .

Dragonflies often land on shiny car parts. Why? Maybe they see the silver shiny surfaces as looking like water.

Thursday, September 8, 2011

Bio 120 Questions for Review- Exam 1 Chapters 1-5

Here are some review questions for you. Some may be similar to the daily review questions, but all will help you while you prepare for the exam.

Chapters 1 and 2
1.How is a hypothesis different from a theory?
2.What are five characteristics of living things?
3. What is a hydrogen bond, and why are these bonds important to life?
4. Oxygen has 8 electrons, with 6 in the outermost energy level. Will this atom react?
5. How are ions formed?
6. A solution with a pH of 5 is how many times more acidic than a solution with a pH of 7?
7. What determines if an atom with react with another?
8. How are polar and non polar covalent bonds different?
9. How is the polar nature of water related to:
a. its high boiling point
b. surface tension
c. the solid form being less dense than the liquid form


Chapter 3
1. What are the building blocks of carbohydrates?
2. What is the difference between a saturated and unsaturated fatty acid?
3. Why is the shape of an enzyme important to the function of the enzyme?
4. At what level of complexity do proteins usually become functional?
5. What makes up a nucleotide?
6. What bond forms between amino acids as they react to form proteins?
7. How is the function of carbohydrates different in plants and animals?
8. Which of the macromolecules we discussed stores energy in the most efficient way?
9. What is the most common steroid in the body?

Chapter 4
1. How are the mitochondria and chloroplasts similar?
2. Why do we think the mitochondria was once an independent organism?
3. Describe the plasma membrane. Include how a lipid membrane functions in a watery environment.
4. What role do the proteins in the plasma membrane play?
5. How are prokaryotic cells different from eukaryotics cells?
6.What can cyanobacteria do that the bacteria living in your mouth do not do?
7.How are archeae different from the bacteria living on your skin?
8.Describe briefly what organelles would be involved in making a protein and exporting it from the cell.
9.Give an example of two cell organelles working together to accomplish a task.
10.What organelle is found on the ER?
11.What is the function of lysosomes?
12.Where is the nucleolus, and what is its function?
13.What are the functions of the Golgi bodies?

Chapter 5

1. A plant cell in a hypertonic solution will under go _____________
2. An animal cell in a hypotonic solution may undergo _____________
3. A cell must maintain an imbalance of sodium ions on either side of the membrane for it to function. What process would it most likely use of the ones we discussed in class?
4. How is active transport different from diffusion and osmosis?
5. How is dialysis different from osmosis?
6. What affect would a hypertonic solution have on a cell?
7. In a hypotonic solution water would move ________ a cell.
8. If a .9% salt solution is isotonic to a red blood cell, a 2% salt solution would be _____.