ch 16,17,19

Question 1

bacteriophage

Answer 1

a virus that infects bacteria

Question 2

mismatch repair

Answer 2

when cells use special enzymes to fix incorrectly paired nucleotides

Question 3

telomeres

Answer 3

nucleotide sequences at the end of eukaryotic chromosomal dna used to postpone the gradual destruction of genes near the ends of dna molecules

Question 4

telomerase

Answer 4

accelerates the lengthening of telomeres in germ cells

Question 5

snRNPs

Answer 5

ribonucleoproteins: recognize the splice sites

Question 6

ribozymes

Answer 6

rna molecules that functions as enzymes and can splice rna

Question 7

UTR

Answer 7

untranslated region: the section of mrna that immediately follows the translation termination codon

Question 8

domains

Answer 8

discrete structural and functional regions of a protein

Question 9

aminoacyl-trna synthetase

Answer 9

joins each amino acid to the correct trna

Question 10

wobble

Answer 10

relaxation of base pairing rules

Question 11

polyribosomes

Answer 11

the number of ribosomes that can translate single mrna simultaneously

Question 12

post translational modification

Answer 12

Insulin: starts as single polypeptide chain, becomes active after central part is cut out of the chain so it is now 2 polypeptide chains

Question 13

mutation

Answer 13

change in genetic material of cell or virus

Question 14

point mutation

Answer 14

chemical change in 1 base pair of a gene

Question 15

base pair substitution

Answer 15

replaces 1 nucleotide and its partner with another pair of nucleotides

Question 16

missense mutation

Answer 16

when a codon still codes for an amino acid but may not always be the right one

Question 17

nonsense mutation

Answer 17

change in amino acid codon into a stop codon that usually leads to a nonfunctional protein

Question 18

mutagen

Answer 18

physical or chemical agent that causes a mutation

Question 19

cell differentiation

Answer 19

process where a generic cells turns into a special cell

Question 20

histone acetylation

Answer 20

promotes transcription by modifying chromatin structure

Question 21

histone deacetylation

Answer 21

decreases transcription

Question 22

dna methylation

Answer 22

decreases transcription

Question 23

epigenetic inheritance

Answer 23

the inheritance of traits transmitted by mechanisms not directly involved in the nucleotide sequence

Question 24

rna interference

Answer 24

when double stranded rna can turn off genes with the same sequence

Question 25

proteasomes

Answer 25

giant proteins that break up protein molecules into amino acids

Question 26

Alu elements

Answer 26

transposable elements that do not code for a protein but are transcribed into rna molecules

Question 27

multi-gene families

Answer 27

collections of identical/very similar genes

Question 28

pseudogenese

Answer 28

nonfunctional nucleotide sequences similar to functional genes