Biology Unit 6

Question 1

Base triplets in mRNA strand

Answer 1

Codon

Question 2

Any change in DNA

Answer 2

Mutation

Question 3

Base sequence must be removed before translation

Answer 3

Intron

Question 4

Contains that bases Adenine and Guanine

Answer 4

Purines

Question 5

Gene variations that arise by mutation and exist at the same relative location on homologous chromosomes

Answer 5

Allele

Question 6

Three-nucleotide sequence in a tRNA molecule that corresponds to an mRNA codon

Answer 6

Anticodon

Question 7

Process through which messenger RNA forms on a template of DNA

Answer 7

Transcription

Question 8

Physical and functional unit of heredity, a sequence of DNA that codes for a protein

Answer 8

Gene

Question 9

Total gene information of a cell or organism

Answer 9

Genome

Question 10

DNA sequence to which RNA polymerase and associated factors bind and initiate transcription

Answer 10

Promoter

Question 11

DNA fragment that is synthesized in short stretch son the lagging strand

Answer 11

Okazaki Fragment

Question 12

Set of all codons

Answer 12

Genetic Code

Question 13

Nucleotides linked by covalent bonds

Answer 13

Phosphodiester

Question 14

Mutation in which DNA sequence jumps into middle of Gene : these segments can turn on and off genes

Answer 14

Transposon

Question 15

Making a mRNA molecule from the DNA Template

Answer 15

Translation

Question 16

What is Chargaff’s Rule?

Answer 16

A=T

C=G

Question 17

Why is the DNA molecule described as being antiparallel?

Answer 17

One strand runs 5’ to 3’ and the other runs 3’ to 5’

Question 18

Describe the organization of a DNA nucleotide

Answer 18

Carbon atoms in sugar designated by numbers (1’ to 5’)
- Nitrogenous Base on 1’
- Hydroxyl Group on 3’
- Phosphate on 5’
Nucleotides form alternating sugar-phosphate backbone.

Question 19

Compare and Contrast RNA and DNA

Answer 19

RNA : contains Ribose, single stranded, bases = ACGU : mRNA, tRNA, rRNA

DNA : polymer of nucleotides (deoxyribose, phosphate, and one of the four nitrogenous bases). : Base = purines and Pyrimidines : double helix (anti-parallel strand).

Question 20

What are the Different Types of RNA? What are their Functions?

Answer 20

Messenger RNA : translation of RNA from Nucleus to ribosomes

Transfer RNA : carries amino acid triplet codes to the mRNA

Ribosome RNA : catalyst assembly of amino acids into protein chains.

Question 21

What does it mean when the genetic code is described as redundant?

Answer 21

The genetic code is described as redundant which means it having more codons than amino acids.

Question 22

DNA replication is described as semi-conservative. What does that word mean?

Answer 22

Bases on “old” strand join nucleotide to form “new” strand.

Question 23

Distinguish between the terms leading strand and lagging strand. In your description, include the term Okasaki Fragments.

Answer 23

DNA replication occurs continuously only in the 5’ to 3’ direction (leading strand)

Replication can only occur discontinuously in the 3’ to 5’ (lagging strand)
-> short 5’ to 3’ stretches are added one at a time, which are Okasaki fragments

Question 24

What are the enzymes that are involved in DNA replication? Describe the function of each enzyme.

Answer 24

DNA Polymerase : attach short stretches of nucleotides to unwound part of template

DNA ligase : fill in tiny gaps between new short stretches to form continous strand

DNA heliocase : unzips the DNA molecule into two pieces

Enzyme repair DNA where base-pairing errors have crept into nucleotide sequence.

Question 25

Transcribe and Translate the following DNA sequence :

Answer 25

5’ CATTTCACGGAGACT 3’
GUAAAGUGCCUCUGA
Val , Lys , Cys , Leu

Question 26

If a mutation deleted the second T base, how would protein synthesis be effected?

Answer 26

5’ CATTCACGGAGACT 3’
GUAAGUGCCUCUGA
Val , Ser , Ala , Ser

Question 27

Distinguish between point and frameshift mutation

Answer 27

Point mutation : change in only one nucleotide

Frameshift : one or more nucleotides inserted or deleted form molecule, causes alteration in reading frame

Question 28

Distinguish between missence and frameshift mutations

Answer 28

Missence : replace of one amino acid for another

Nonsense : convert codon to termination codon

Question 29

Parts of mRNA that will be translated into protein

Answer 29

Exon