mini test 2

Question 1

What was beadle and tatums experiment

Answer 1

tested on mold to show that each gene encodes a specific enzyme

Question 2

define gene

Answer 2

basic unit of inheritance

Question 3

what is the coding region?

Answer 3

where the template for RNA (transcription occurs

Question 4

what is an exon?

Answer 4

the coding region for gene that codes for protien

Question 5

what is a intron?

Answer 5

non coding DNA transcript that get spliced out

Question 6

what is chromatin

Answer 6

DNA wrapped around histone protiens

Question 7

describe the central dogma

Answer 7

information is encoded into dna then transcribed into mRNA then translated into amino acids that code for protiens

Question 8

describe the characteristics of a bacteria

Answer 8

• no membrane bound organelles
  -circular DNA
• translation and transcription occur in the same location

Question 9

what does a promotor do?

Answer 9

promotor is found in the DNA of an operon and determines if the gene will be expressed or not based on environmental conditions

Question 10

what is the trp operon?

Answer 10

no trp = the protein is produced
trp present = bonds to receptor which turns off the operon - this is so the cell doesnt have too much trp

Question 11

describe gene expression in eukaryotes

Answer 11

for a gene to be expressed, histones either need to be unraveled or coiled tighter - histones attached to functional groups via covalent bonds can modify teh expression

Question 12

Why is BASAL general transcription factors important?

Answer 12

they bind to the promotor on DNA to initiate transcription

Question 13

what are enhancers and distal promotors

Answer 13

promotes high levels of expression

Question 14

list different types of mutations

Answer 14

point mutation (deletion or insertion)

Question 15

define a gamete

Answer 15

a haploid sex cell

Question 16

define somatic cell

Answer 16

undifferentiated cell - 46 chromosomes

Question 17

what are the steps of meiosis 1

Answer 17

pro - rna recombination and cross over occurs
met - spindles attach to centromere and they line up along the middle
ana - they are pulled to opposite polls
tel - the separate completely
cyt - they become 2 cells

Question 18

what are different forms of genetic variation?

Answer 18

independent assortment, mutation, recombination

Question 19

how do you do a test cross

Answer 19

f1 x P

Question 20

what is the monohybrid ratio

Answer 20

3:1

Question 21

what is the point of test crosses

Answer 21

infer the genotype from the phenotype - cross unknown individual with recessive homozygous

Question 22

describe the process of the Lac operon

Answer 22

its the metabolic pathway for breaking down lactose
an absence of lactose = lac repressor is present (shuts does lac gene)
lactose present = repressor detaches and DNA polymerase binds to promotor to turn on lac gene

Question 23

what is a positive regulator?

Answer 23

activators

Question 24

what is a negative regulator?

Answer 24

repressors

Question 25

what happens (in relation to lac operon) when there is no glucose in the system

Answer 25

cyclic AMP increases. this will bind to CAP (protein) then to the CAP receptor site = increased rates of transcription of lac gene

Question 26

what are the 3 steps of PCR reactions

Answer 26

1. denaturation: strands seperate 2. annealing: primers attach 3. extension: Taq polymerase incorperates base pairs to reform DNA

Question 27

what will a taster mutation look like

Answer 27

more then 1 line due to cuts from restriction enzyme

Question 28

what are the methods of DNA transfer between bacteria

Answer 28

1. conjunction: direct cell contact 2. transformation: incorperation of naked DNA 3. transduction: transfer of chromosomal or plasmid DNA from cell to cell by bacterial viris

Question 29

independent assortment vs law of segregation?

Answer 29

independent assortment: alleles of different genes assort into gametes segregation: alleles of the same gene assort into different gametes