A1.2

Question 1

What are nucleic acids?

Answer 1

The information molecules of cells which can be split into two types, deoxyribonucleic acid (DNA) or ribonucleic acid (RNA)

Question 2

What is genetic code?

Answer 2

the code containing the information in the nucleic acids which is universal (in all organisms)

Question 3

Where is DNA found?

Answer 3

chromosomes of the nucleus (and chloroplasts and mitochondria)

Question 4

Where is RNA found?

Answer 4

in the cytoplasm and more specifically in the ribosomes

Question 5

What is a nucleotide made of?

Answer 5

A nitrogenous base, a pentose sugar, a phosphate group

Question 6

What are the 4 nitrogenous bases for DNA?

Answer 6

Adenine, thymine, cytosine and guanine

Question 7

What reaction forms a nucleotide?

Answer 7

condensation reaction

Question 8

What is the sugar phosphate backbone?

Answer 8

Alternating sugar and phosphate molecules, each base is attached to a pentose sugar that alternates with a phosphate molecule.

Question 9

Where does the genetic code lie?

Answer 9

in the coding strand

Question 10

How many different combinations are there?

Answer 10

64 (4x4x4)

Question 11

What is a codon?

Answer 11

a three-letter or triplet code with each sequence standing for one of the 20 amino acids

Question 12

What are the 4 nitrogenous bases for RNA?

Answer 12

adenine, uracil, cytosine, guanine

Question 13

What are the 3 functional types of RNA?

Answer 13

Messenger RNA( mRNA), transfer RNA (tRNA) and ribosomal RNA (rRNA)

Question 14

What is the bond in RNA formed between adjacent nucleotides called?

Answer 14

3’-5’ phosphodiester bond

Question 15

How is RNA formed?

Answer 15

the condensation of nucleotide monomers

Question 16

What is the DNA double helix?

Answer 16

two antiparallel polynucleotide strands paired together and held by hydrogen bonds

Question 17

What are the sections that code for proteins called?

Answer 17

genes

Question 17

What is a gene?

Answer 17

A heritable factor that influences a feature of an organism such as height

Question 18

Where are genes located?

Answer 18

each gene occupies a specific position on a chromosome hence each chromosome is a linear series of genes

Question 19

What is a locus?

Answer 19

the point where a gene for a particular characteristic is found every time

Question 20

What is an allele?

Answer 20

Each gene had two or more forms called alleles

Question 21

What is a homologous chromosome?

Answer 21

chromosomes of eukaryotic cells that occur in pairs

Question 22

What us complementary base pairing?

Answer 22

the combinations that fit together on the helix since they only form hydrogen bonds with each other, adenine and thymine, cytosine and guanine

Question 23

what are conserved sequences?

Answer 23

sequences that remain unchanged or only slightly changed

Question 24

What are the most highly conserved genes?

Answer 24

The ones that can be found in all organisms

Question 25

How is DNA packed into chromosomes?

Answer 25

by coiling the DNA double helix and looping it around protein beads called nucleosomes

Question 26

What is a nucleosome made of?

Answer 26

eight histone molecules make one bead

Question 27

What was the Hershey and Chase experiment?

Answer 27

an experiment to prove that DNA was the holder of information in the cell and not protein

Question 28

How did Hershey and chase conduct the experiment?

Answer 28

They labeled two different bacteriophages, one with DNA and one with protein and let them infect cultures of e coli. They observed that only the bacteriophage marked with DNA was transferred to the next generation