Ch.17: Genes and Proteins

Question 1

Our DNA accounts for specific traits by

Answer 1

dictating the synthesis of proteins

Question 2

are the links between genotype and phenotype

Answer 2

protein

Question 3

The process by which DNA directs protein synthesis is called

Answer 3

Gene Expression

Question 4

Gene expressionincludes two stages:

Answer 4

Transcription and translation

Question 5

the genetic code is written into a strand of mRNA. It is the synthesis of RNA under the direction of DNA. produces mRNA

Answer 5

transcription

Question 6

the mRNA code is converted into an amino acid sequence. It is the synthesis of a polypeptide, which occurs under the direction of mRNA

Answer 6

translation

Question 7

what is the intermediate between genes (DNA) and the proteins for which they code. SINGLE STRANDED

Answer 7

RNA

Question 8

Translation heavily relies on

Answer 8

Transfer RNA (tRNA)

Question 9

There are 20 amino acids, but there are only

Answer 9

four nucleotide bases in DNA

Question 10

The flow of information from gene to protein is based on a

Answer 10

triplet code

Question 11

a series of three-nucleotides called

Answer 11

codon

Question 12

These triplets can code for

Answer 12

all amino acids

Question 13

The three stages of transcription are:

Answer 13

Initiation
Elongation
Termination

Question 14

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides

Answer 14

introns

Not providing instructions

Question 15

Coding regions are called______because they are eventually expressed, usually translated into amino acid sequences

Answer 15

exons

Question 16

removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence

Answer 16

RNA Splicing

Question 17

A cell translates an mRNA message into protein with the help of

Answer 17

Transfer RNA

Question 18

Molecules of tRNA are not identical:

Answer 18

Each carries a specific amino acid on one end
Each has an anticodon on the other end
the anticodon base-pairs with a complementary codon on mRNA

Question 19

Protein synthesis:

Answer 19

1.RNA polymerase transcribes RNA from DNA
2.introns are excised from the RNA transcript, and the
remaining exons are spliced together, producing mRNA.
3.ribosomal subunits bind to the mRNA
4. tRNA molecules become attached to specific amino acids
5.tRNAs bring their amino acids in at the A site on the ribosome.
6. Peptide bonds form between amino acids
7The polypeptide chain grows until the protein is completed

Question 20

True or False: Genes can be transcribed and translated after being transplanted from one species to another

Answer 20

True, because genes are universal

Question 21

are changes in the genetic material of a cell, the raw material for evolution, not directly beneficial

Answer 21

mutations

Question 22

are chemical changes in just one base pair of a gene, sickle cell

Answer 22

point mutation

Question 23

Point mutations within a gene can be divided into two general categories

Answer 23

Base-pair substitutions
(Nucleotides are inserted or substituted for others)
Base-pair insertions or deletions
(Add or take away a nucleotide)

Question 24

replaces one nucleotide with another

Answer 24

base pair substitution

Question 25

have no effect on the amino acid because of redundancy in the genetic code

Answer 25

silent mutation

Question 26

code for a different amino acid

Answer 26

missense mutation

Question 27

change an amino acid codon into a stop codon, nearly always leading to a nonfunctional protein

Answer 27

nonsense mutation

Question 28

Insertion or deletion of nucleotides may alter the reading frame, producing a

Answer 28

frameshift mutation

Question 29

We have considered a gene as:

Answer 29

A discrete unit of inheritance
A region of specific nucleotide sequence in a chromosome
A DNA sequence that codes for a specific polypeptide chain