DNA

Question 1

What is DNA? What does it stand for? What is it composed of?

Answer 1

• DNA stands for deoxyribonucleic acid
• DNA is the blueprint of life (has the instructions for making an organism) and determines traits passed from one generation to the next
• composed of nucleotides (which contain a sugar (ribose/deoxyribose), a phosphate group, and a nitrogenous base)

Question 2

What is DNA’s purpose/function?

Answer 2

to store and transmit genetic information that is essential for the growth, development, functioning, and reproduction of organisms

Question 3

Complementary bases of DNA

Answer 3

adenine, cytosine, guanine, thymine

Question 4

What is DNA replication

has to do with cells; be specific in what it does

Answer 4

• the process by which a cell makes an exact copy of its DNA before cell division, ensuring that each daughter cell receives an identical set of genetic instructions.

Question 5

What happens in DNA replication? (Include where it starts, location, and each step including result)

be specific in all steps, list the name of each enzyme ad what it does

Answer 5

• starts in interphase (synthesis)
• in the nucleus
• 1) DNA untwists and a helicase enzyme begins to break the hydrogen bonds between complementary nucleotides, forming a replication fork
• 2) a polynease enzyme runs along the parent chain of DNA and bonds free-floating nucleotides based (NOT bases) upon base-pairing rules (a-t and g-c)
• 3) results into 2 identical DNA molecules

Question 6

DNA replication results

Answer 6

2 identical DNA molecules

Question 7

Why does DNA replication happen

Answer 7

• to ensure that each (new) cell produced during cell division has an identical copy of the genetic material
• fundamental to life/growth/development

Question 8

Describe who Chargaff was and what he created/discovered/his significance

Answer 8

• analyzed the base composition (base pairing rules) of DNA
• discovered the base-pairing rules that a=t and c=g
• important because it helped explain the structure of DNA and ensured that the nucleotide composition was not random
• influenced the development of the double-helix model of DNA by Watson and Crick

Question 9

Describe who Watson and Crick was and their significance

Answer 9

• discovered the structure of DNA (double helix)
• allowed scientists to understand how DNA could carry genetic information/how it could be replicated
• Rosalind Franklin helped but was not credited

Question 10

enzymes involved in DNA replication

Answer 10

• helicase (breaks hydrogen bonds)
• polynease (bonds free floating nucleotides)