Exam 2 Review: DNA and Mitosis Bio 120

Here are some review questions to get you started.
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?

NASA scientist discovers new life form

GFAJ-1
Remember how I always say all life on Earth makes DNA the same way? That life builds DNA with a backbone of sugar and phosphate? Well, not anymore. Nasa Scientist Felisa Wolfe Simon and her team of researchers have discovered a bacterium that does not build its DNA with phosphate, but uses Arsenic instead!!



The organism was discovered in Mono Lake here in California. This bacteria, called GFAJ-1 can eat arsenic, but so can a few other bacteria. What makes this bacteria so unusual is that it makes its DNA from it!

Arsenic is very toxic to most of us, but this single celled organism has found a way to make DNA, RNA, proteins and even its cell membranes from it.


To read the press release from NASA click here

Tinkering with Ribosomes and Protein Production

National Public Radio had a story this week about making new kinds of proteins by altering the way the ribosomes read the DNA code. As you know, ribosomes understand mRNA in groups of three bases called codons. Listen to this short report about scientists who have discovered how to get ribosomes to recognize codons made of four bases.

DNA Review

Here are some review questions about DNA from the lecture today.

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 complemetary 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?

Let's Rap About Genes ( and DNA while we are at it)

DNA a "bar code" for plants?

Last year researchers from the Royal Botanical Gardens in England in collaboration with researchers at the University of Johannesburg and the University of Costa Rica, discovered a gene that could be used to readily identify plant specimens. This gene called the matK gene is different in different plant species, but has the same DNA sequence in plants of the same species.

This gene could be useful to identify different plant species which look very similar, or to identify plants which have been pulverized for use in medicines or teas.

The use of this gene will also make it possible to identify endangered plant specimens more easily, especially those which physically resemble less rare plants. It could also be used for example, by customs agents trying to detect the illegal importation of rare or endangered plants from other countries.

To read more about this discovery click here

Bio 120 Questions DNA

Here are some review questions about DNA from the lecture today.

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 complemetary 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?