genetics- mutations

Question 1

Variety exists within the same species due to:

Answer 1

variations in genes

Question 2

Mutations are:

Answer 2

permanent changes to the nucleotide sequence of DNA

Question 3

changes in dna can be:

Answer 3

a change in a single base pair, multiple bases or entire sections of chromosomes

Question 4

mutations can create:

Answer 4

new alleles and therefore new traits

Question 5

DNA Replication:

Answer 5

copying of dna during cell divisions results in mistakes

most errors are corrected but humans pass on about 100-200 mutations per generation

Question 6

Mutagens cause:

Answer 6

damage to DNA

increasing the likelihood of mutations

Question 7

Examples of mutagens are:

Answer 7

ionizing radiation such as uv lights and xrays strid electrons from dna, breaking bonds

chemicals like benzene and heavy metals can bind to the dna molecule and disrupt the structure

some viruses insert themselves into the dna strand, disrupting the nucleotide sequence

Question 8

define: carcinogen

Answer 8

a substance or agent that causes cancer

some mutagens are carcinogenic such as uv radiation, cigarette smoke

Question 9

the 3 types of mutations are

Answer 9

substitution, insertion and deletion

Question 10

substitution is when:

Answer 10

a single base(A,T,G,C,) is exchanged for another

this will change only one amino acid

Question 11

insertion is when:

Answer 11

One or more bases are added to the nucleotide sequence

the insertions moves the subsequent nucleotides over, changing everything after the mutation

Question 12

deletion is when:

Answer 12

one or more of the bases are removed from the sequence, as with insertion, the frame shift changes everything after the mutation

Question 13

Using genetic information from DNA we can assemble:

Answer 13

a protein using mRNA and the genetic code

Question 14

3 mRNA bases =

Answer 14

codon which is specific for one amino acid

Question 15

AUG is:

Answer 15

Start codon at the beginning of each protein sequence

Question 16

The three stop or terminator codons are:

Answer 16

UAA, UAG, UGA

they are at the end of a gene and cause a releasing factor to let go of the protein

Question 17

DNA to Protein:

Answer 17

Transcripted to become RNA then translated to form amino acids which for proteins

Question 18

Three effects of mutatinos

Answer 18

positive, negative, neutral

Question 19

Define: Positive mutation

Answer 19

any mutation that improves the function of a gene by causing it to create better protein

will give an organism an advantage over other members of its species

Question 20

Define: Negative mutation

Answer 20

any mutation that decreases the function of a gene by creating a nonfunctional protein

negative mutations will place an organism at a disadvantage

Question 21

Define: Neutral Mutation

Answer 21

any mutation that does not change the function of a protein

neutral mutations create proteins that are identical or have equivalent function