Bio Test Feb 18

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic acid

Question 2

What are the 2 reasons why DNA is unique?

Answer 2

Contains entire genetic code
Can copy itself exactly

Question 3

What are the building blocks (monomers) of DNA?

Answer 3

Nucleotides

Question 4

What are the 3 parts of a nucleotide? (be able to identify each part on a diagram)

Answer 4

1.phosphate group
2. Sugar molecule
3.nitrogenous base

Question 5

What are the 4 nitrogen bases present in DNA?

Answer 5

Adenine, cytosine, guanine, thymine.

Question 6

What are purines? How many rings do they have?

Answer 6

Adenine & Guanine
2 rings

Question 7

What are pyrimidines? How many rings do they have?

Answer 7

One ring carbon nitrogen ring bases
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

Francis Crick
James Watson
Rosalind Franklin
Maurice Wilkins
1953

Question 9

What did Erwin Chargaff discover?

Answer 9

In DNA adenine, thymine, guanine, and cytosine are equal amounts.

Question 10

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

Answer 10

Sugar and phosphate groups

Question 11

What holds the DNA molecule together?

Answer 11

Hydrogen bonds

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 goes with Thymine
Cytosine goes with Guanine

Question 14

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

Answer 14

DNA Helicase

Question 16

What does DNA polymerase do?

Answer 16

Forms new copies of DNA in the form of nucleic acid molecules.

Question 17

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

Answer 17

TAA GGC

Question 18

What are the 3 types of RNA?

Answer 18

• Messenger RNA: Carry the coding sequence for protein synthesis and are called transcripts
• Ribosomal RNA: Scaffolding for Ribosomes (needed to make proteins)
• Transfer RNA: Carries amino acids to the ribosomes during protein synthesis

Question 19

What are 4 differences between RNA and DNA?

Answer 19

• RNA has uracil instead of thymine
• DNA is double stranded and RNA is normally single stranded
• The sugar in DNA is deoxyribose while in RNA it contains Ribose
• DNA stays in the nucleus and RNA can leave the nucleus

Question 20

What is transcription?

Answer 20

The process of copying DNA into RNA.

Question 21

Where does transcription occur in the cell?

Answer 21

Nucleus

Question 22

Briefly describe the steps of transcription.

Answer 22

• RNA Polymerase unwinds the DNA breaking Hydrogen bonds
• Free RNA forms bases and pairs with the original DNA strand
• RNA nucleotides bind together forming mRNA strands

Question 23

What enzyme is responsible for transcription?

Answer 23

RNA polymerase

Question 24

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

Answer 24

Goes through the nuclear pores that let things out but not in.

Question 25

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

Answer 25

TTG CGA

Question 26

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

Answer 26

Codon

Question 27

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

Answer 27

AUG, methionine

Question 28

What are the 3 stop codons?

Answer 28

* UAG * UAA * UGA

Question 29

What is translation?

Answer 29

The process of making proteins from the information in the mRNA strand.

Question 30

Where does translation occur in the cell?

Answer 30

Cytoplasm

Question 31

What does the word 'mutation' mean?

Answer 31

To change

Question 32

Mutations that produce changes in a single gene are called ____

Answer 32

Gene mutations

Question 33

Mutations that produce changes in whole chromosomes are known as _____

Answer 33

Chromosomal mutations

Question 34

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

Answer 34

Substitution

Question 35

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

Answer 35

* Missense: The mutation changes an amino acid * Nonsense: The mutation stops the protein from being made * Silent: The mutation has no effect

Question 36

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

Answer 36

The entirety of a letter in the DNA doesn't do what it's supposed to do or they all shift and get mixed signals.

Question 37

What are the 4 examples of chromosomal mutations?

Answer 37

* Deletion: The loss of all or part of the chromosomes * Duplication: Produces an extra copy of all or part of a chromosome * Inversion: Reverses the direction of the chromosome * Translocation: A piece of one chromosome detaches and attaches to another chromosome.