Chapter 12 Study Guide

Question 1

What is the primary function of DNA?

Answer 1

to transfer and store genetic info throughout cell

Question 2

Explain the structure of DNA (what does the DNA “ladder” look like?)

Answer 2

double helix shape
Twisted ladder shape- rails are sugar and phosphates
rungs- bases connected by hydrogen bonds

Question 3

Which scientists are credited with establishing the structure of DNA?

Answer 3

Watson and Crick

Question 4

What is Chargoff”s rule? Which bases are paired together?

Answer 4

A=T G=C

Question 5

What is a chromosome

Answer 5

threadlike strand of DNA in nucleus that carries genes- is tightly coiled around proteins

Question 6

What does a nucleotide consist of?

Answer 6

base, phosphate, sugar

Question 7

Order from largest to smallest: nucleotide, chromosome, cell, DNA, nucleus

Answer 7

cell, nucleus, chromosome, DNA, nucleotide

Question 8

What is the difference between a purine and a pyrimidine?

Answer 8

Purine- 2 rings

Pyrimidine- single ring

Question 9

Explain the process of DNA replication (includes enzymes)

Answer 9

DNA helicase unzips DNA
DNA polymerase helps find nucleotides to match
Each DNA strand has 1 parent and 1 daughter strand

Question 10

Why is DNA replication called semiconservative replication

Answer 10

half of the new DNA is the parent strand and one is the daughter strand

Question 11

The sequence of bases on one strand of a DNA molecule is AGCCTAG. After replication of the strand of DNA, what is the sequence of nitrogen bases in the complementary strand?

Answer 11

TCGGATC

Question 12

What are the three types of RNA

Answer 12

mRNA, tRNA, and rRNA

Question 13

Which type of RNA carries instructions for making proteins?

Answer 13

mRNA

Question 14

What is the start codon?

Answer 14

AUG

Question 15

How many different amino acids are there?

Answer 15

20

Question 16

Explain transcription and where it takes place

Answer 16

synthesis of mRNA from DNA

nucleus

Question 17

Explain translation and where it takes place

Answer 17

where code is read and translated to make a protein

cytoplasm

Question 18

How is RNA different from DNA (list 3 differences)

Answer 18

RNA is single stranded not double stranded
RNA has uracil not thymine
RNA has ribose instead of deoxyribose

Question 19

Each codon is linked to how many amino acids

Answer 19

1

Question 20

What is the series of amino acids encoded by this piece of mRNA?
CUCAAGUGCUUC

Answer 20

leucine, lysine, cysteine, phenylalanine

Question 21

The anticodons for the codons CUCAAGUGCUUC are

Answer 21

GAGUUCACGAAG

Question 22

Essay-

Explain the central dogma (DNA to RNA to proteins)

Answer 22

DNA replicates to mRNA

mRNA connects to ribosome and pairs with the anticodon

Question 23

How is the shape of a protein related to its amino acid sequence

Answer 23

it is based on how amino acids interact with each other and water

Question 24

Which class of biological molecule includes enzymes and the structures that determine most observable traits in living things?

Answer 24

proteins

Question 25

What is the function of tRNA?

Answer 25

transport amino acids to ribosome

Question 26

Explain gene regulation in a eukaryotic cell

Answer 26

it controls what genes are expressed at a certain time

Question 27

What is a mutation

Answer 27

permanent change that occurs in a cell’s DNA

Question 28

Are the effects of a mutation always harmful?

Answer 28

no some can provide camouflage from predators and some don’t do anything at all

Question 29

Original gene- TTGACTCGGTATAC
Mutant gene- TTGACTCGTATAC
What type of mutation is this? What is a possible cause of this mutation?

Answer 29

frameshift- deletion

exposure to mutagens ;like radiation