Unit #1: DNA, RNA, and Protein Synthesis review

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic acid

Question 2

What are the 2 reasons why DNA is unique?

Answer 2

It contains our genetic code
It replicates itself exactly

Question 3

What are the building blocks (monomers) of DNA?

Answer 3

nucleotide

Question 4

What are the 3 parts of a nucleotide?

Answer 4

5-carbon sugar (deoxyribose), phosphate group, nitrogenous base

Question 5

What are the 4 nitrogen bases present in DNA?

Answer 5

Adenine, guanine, cytosine, thymine

Question 6

What are purines? How many rings do they have?

Answer 6

They are types of nitrogenous bases with 2 rings
Adenine, guanine

Question 7

What are pyrimidines? How many rings do they have?

Answer 7

A type of nitrogenous base with 1 ring
Thymine, cytosine

Question 8

The double helix structure of DNA was discovered by 4 scientists - what are their names and what was the year?

Answer 8

1953, Rosalind Franklin, James Watson, Francis Crick, Maurice Wilkins

Question 9

What did Erwin Chargaff discover?

Answer 9

He found that the ratio of Adenine and thymine are almost equal, the same with guanine and cytosine

Question 10

What is the “backbone” of DNA made up of?

Answer 10

Deoxyribose and phosphates

Question 11

What holds the DNA molecule together?

Answer 11

Nitrogenous bases

Question 12

The nitrogen bases are always connected to the (sugar or phosphate)?

Answer 12

sugar

Question 13

Name the complementary strands of a DNA molecule.

Answer 13

Adenine and thymine, guanine and cytosine

Question 14

What enzyme “unzips” the 2 strands of DNA in DNA replication?

Answer 14

DNA helicase

Question 15

What does DNA polymerase do?

Answer 15

Joins individual nucleotides to produce the “new” DNA molecule

Question 16

If one strand of DNA if ATT CCG, what is the other complementary strand of DNA?

Answer 16

TAA GGC

Question 17

What are the 3 types of RNA? What does each type do?

Answer 17

mRNA: copies the DNA exactly and takes it to the cytoplasm through the nuclear pores
tRNA: bonds to a specific amino acid and carries that amino acid to the ribosome
rRNA: converts the RNA into a protein

Question 18

What are 4 differences between RNA and DNA?

Answer 18

DNA is permanent, RNA is temporary
RNA has Uracil, DNA has Thymine
RNA is in the cytoplasm, DNA is in the nucleus
DNA has two strands, RNA has one

Question 19

What is transcription? Where does it occur in the cell (nucleus or cytoplasm)?

Answer 19

It is when the code of DNA is copied onto RNA, it occurs in the nucelus

Question 20

Briefly describe the steps of transcription.

Answer 20

RNA polymerase copies the DNA in the nucleus until it reached the stop codon and creates mRNA

Question 21

What enzyme is responsible for transcription?

Answer 21

RNA polymerase

Question 22

How does mRNA move from the nucleus to the cytoplasm of a cell?

Answer 22

It goes through the nuclear pores

Question 23

If an RNA molecule contains the sequence AAC GCU, what is the sequence of the DNA molecules from which it was made?

Answer 23

TTG CGA

Question 24

A series of 3 mRNA nitrogen bases that contains the information needed to make proteins are called what?

Answer 24

A codon

Question 25

What is the universal start codon and what amino acid does it code for?

Answer 25

AUG, methionine

Question 26

What are the 3 stop codons?

Answer 26

UAA, UAG, UGA

Question 27

What is translation? Where does it occur in the cell (nucleus or cytoplasm)?

Answer 27

It is when the newly made mRNA strand is translated into a chain of amino acids (protein), in the cytoplasm

Question 28

Find the mRNA strand, tRNA anticodon and amino acid sequence for the following DNA strand: TAC CCT CAT ACT

Answer 28

mRNA: AUG GGA GUA UGA tRNA: UAC CCU CAU ACU Amino acid: met, pro, his, thr

Question 29

What does the word “mutation” mean?

Answer 29

To change - a change in genetic material

Question 30

Mutations that produce changes in a single gene are called ____

Answer 30

Point mutations

Question 31

Mutations that produce changes in whole chromosomes are known as _____

Answer 31

Missense mutations

Question 32

In what way(s), if any, do most mutations change organisms?

Answer 32

They allow organisms to have physical differences

Question 33

What are the 3 examples of gene (point) mutations?

Answer 33

Deletion, insertion, substitution

Question 34

Insertions and deletions usually result in frameshift mutations. What does this mean?

Answer 34

That every base from then on will either be one forward or backward

Question 35

What are the 4 examples of chromosomal mutations? Explain each.

Answer 35

Deletion: a part or all of a chromosome is lost Duplication: part of the chromosome is duplicated Inversion: part of the chromosome is reversed Translocation: part of the chromosome breaks off and attaches to another chromosome