Exam 3

Question 1

centrioles

Answer 1

organize microtubules that form spindle (called and aster)

-not in plants

Question 2

Why Mendel’s ratios work

Answer 2

1. segregation- discrete units, genes don’t blend
2. independent assortment- characteristics are separate (color and shape)
3. dominance

Question 3

Why Mendel’s ratios don’t work??

Answer 3

1. incomplete dominance- red+white flower = pink
   - multiple alleles
2. Co-cominance of multiple alleles- A can be dominant and B can be dominant
   - enviormental factors and polygenetic

Question 4

polygenic inheritance

Answer 4

multiple gene loci are involved in controlling phenotype of trait

• more than one gene for trait
• height (range)

Question 5

pleiotropy

Answer 5

a single gene affects more than one trait

-sickle cell anemia

Question 6

epistasis

Answer 6

product of 1 gene interacts with another

-pigment and enzymes interacting

Question 7

Meselson and Stahl

Answer 7

N14 and N15 put bacteria in concentrations and see how often replicating by ultracentric fugation

• 1 band after 1, 2 bands after 2
• semiconservative replication is used for DNA

Question 8

ultracentric fugation

Answer 8

spin solution and heavy goes to bottom

Question 9

elongation

Answer 9

new strands of DNA are synthesized by DNA polymerse; make complimentary strands

Question 10

replication fork

Answer 10

DNA splits in half

Question 11

helicase

Answer 11

opens up helix (uncoils)

-leading and lagging strand

Question 12

gyrase

Answer 12

relieves tension created by helicase

-leading and lagging strand

Question 13

single-stranded binding proteins

Answer 13

brings DNA back together when separated

-leading and lagging strand

Question 14

p site

Answer 14

binds the tRNA attached to the growing peptide chain

Question 15

point mutations

Answer 15

alter a single base

Question 16

base modification/deletion

Answer 16

deleting a single base causing a frame shift

-point mutation

Question 17

biotechnology

Answer 17

alternating DNA to create what we want

1. cut DNA with enzyme- restriction endonucleus
2. separate DNA fragments by gel electrophoresis by size
3. add recombinant (GMO) vector to a new cell

Question 18

vector

Answer 18

plasmid or small double stranded circles of DNA

Question 19

recombinant plasmid

Answer 19

recombine DNA; foreign DNA in vector

Question 20

crown gall disease

Answer 20

• dicots
• bacterium has tumor inducing plasmid
• bacteria T-DNA in plant nucleus that then gives hormones that cause gall

Question 21

introns

Answer 21

taken out by SNRPS (non coding areas)

Question 22

exons

Answer 22

coding parts left behid

Question 23

SNRNPS

Answer 23

do the work of cutting and splicing

Question 24

antisense RNA

Answer 24

hydrogen bonds with mRNA so translation and transcription can’t happen

Question 25

anticodons

Answer 25

are the codes which match a complimentary region on the mRNA so that amino acids are assembled in the proper order