Question

dna & dna replication webquest
part 1: dna structure and function video
use any of the links below to watch the dna structure video by teachers pet. as you watch, answer the following questions. tiny url: http://tinyurl.com/teachercdna
full url: https://www.youtube.com/watch?v=gck64zxj46k

1. what does dna stand for?
2. what does the information contained in dna determine?
3. what does dna code for?
4. what are the monomers of dna called?
5. what are the four nitrogen - bases contained in dna?
6. what phrase is used to describe the structure of dna?
7. what is the backbone of dna composed of? which base pairs with cytosine?
8. which base pairs with adenine?
9. label the phosphate and deoxyribose sugar. then write the first initial of the complementary base pairs. write the full name of each base below its initial.

part 2: dna replication article
use any link below to read the dna replication article from the ck12 website. as you read, answer the following questions. tiny url: http://tinyurl.com/8y6oscm
full url: https://www.ck12.org/book/ck12 - biology - book - class - xi/section/7.4/

1. in which phase of the cell cycle does dna replicate?
2. explain why dna replication is a semi - conservative process.
3. what is the role of dna helicase?
4. which enzyme reads and builds a complementary strand of dna?
5. which is the lagging strand synthesized by?
6. which enzyme attaches the okazaki fragments?

Explanation:

1. DNA stands for Deoxyribonucleic Acid.
2. The information in DNA determines an organism's traits and biological functions.
3. DNA codes for proteins.
4. The monomers of DNA are called nucleotides.
5. The four nitrogen - bases in DNA are adenine (A), thymine (T), guanine (G), cytosine (C).
6. The structure of DNA is described as a double - helix.
7. The backbone of DNA is composed of sugar (deoxyribose) and phosphate groups. Guanine pairs with cytosine.
8. Thymine pairs with adenine.
9. In the given DNA structure, the 'P' represents phosphate and the 'S' represents deoxyribose sugar. A pairs with T, T with A, C with G, G with C.
10. DNA replicates in the S phase of the cell cycle.
11. DNA replication is semi - conservative because each new DNA molecule consists of one old strand and one new strand.
12. DNA helicase unwinds and separates the double - stranded DNA.
13. DNA polymerase reads and builds a complementary strand of DNA.
14. The lagging strand is synthesized in short fragments called Okazaki fragments.
15. DNA ligase attaches the Okazaki fragments.

Answer:

1. Deoxyribonucleic Acid
2. An organism's traits and biological functions
3. Proteins
4. Nucleotides
5. a. Adenine (A), b. Thymine (T), c. Guanine (G), d. Cytosine (C)
6. Double - helix
7. Sugar (deoxyribose) and phosphate groups; Guanine
8. Thymine
9. 'P' is phosphate, 'S' is deoxyribose sugar; A - T, T - A, C - G, G - C
10. S phase
11. Each new DNA molecule has one old and one new strand
12. Unwinds and separates double - stranded DNA
13. DNA polymerase
14. In short fragments called Okazaki fragments
15. DNA ligase