Part B: Lecture 6

Question 1

Gene (def.)

Answer 1

DNA region responsible for production of an RNA molecule (mRNA, rRNA etc.)

Question 2

Genes in prokaryotes + eukaryotes general difference

Answer 2

no difference; they work the same way

Question 3

parts of gene (3)

Answer 3

promoter, regulatory region, transcribed region

Question 4

Promoter (def.)

Answer 4

place where RNA pol attaches

Question 5

regulatory regions (def.)

Answer 5

places where transcription factor proteins attach

Question 6

transcribed region produces ____

Answer 6

RNA

Question 7

regulatory region is a _____ that is ____ long

Answer 7

-specific DNA sequence
-10-20 bp long

Question 8

positive transcription factors do what?

Answer 8

recruit RNA polymerase: increase gene activity by making it easier for RNA polymerase to bind

Question 9

negative transcription factors do what?

Answer 9

block the promoter; decrease gene activity by making it harder for RNA poly to bind

Question 10

example of +ve transcription factor

Answer 10

MyoD

Question 11

transcription factors bind which form of DNA? why?

Answer 11

dsDNA; time and energy to open DNA is too much

Question 12

How do TFs bind to DNA?

Answer 12

temporary base hydrogen bonds with no input of energy (spont.)

Question 13

TFs bind to ____ bp to increase ___(2)

Answer 13

several adjacent bp to increase specificity and strength

Question 14

LacZ gene in E-coli produces ____which is an enzyme that ____

Answer 14

-B-Gal (beta-Galactosidase)
-break down lactose brought into cell via transporter

Question 15

Environmental gene expression exists because ___

Answer 15

different environments require different enzymes for survival

Question 16

Environmental gene expression (def.)

Answer 16

when a gene is ‘on’ only in certain environments

Question 17

LacZ gene has a ___ TF called ____

Answer 17

-negative
-lac repressor protein binding on regulatory regions

Question 18

lac repressor protein activity when [lactose] is low

Answer 18

-lactose isn’t bound to protein and it has a high affinity for DNA

Question 19

lac repressor protein activity when [lactose] is high

Answer 19

-lactose is bound to protein and it has a low affinity for DNA

Question 20

Allele (def.)

Answer 20

different forms of gene shown with superscripts or capitalization

Question 21

functional allele representation

Answer 21

a+ or A

Question 22

non-functional allele representation

Answer 22

a- or a

Question 23

LCT gene function (humans)

Answer 23

-codes for lactase: break down lactose outside cell + transporter brings monosaccharide into cell

Question 24

LCT gene regulation

Answer 24

regulated by positive TFS

Question 25

Spatial gene expression (def.)

Answer 25

when gene is on in only some cells; gene expression dependent on location of cell in cellular organism

Question 26

Temporal gene expression (def.)

Answer 26

when gene is on in only some development stages (child vs adult)

Question 27

genotype (def.)

Answer 27

all genes and alleles present in cell/organism

Question 28

Homozygote (def.)

Answer 28

a cell/organism with identical
alleles of a gene of interest

Question 29

Heterozygote (def.)

Answer 29

a cell/organism with different
alleles of a gene of interest

Question 30

G1 & G2 representation of genotype

Answer 30

A/a (single letter not double letter AA/aa)

Question 31

Homologous chromosomes usually have same ____ (4)

Answer 31

length
centromere position
bands
genes

Question 32

Homologous chromosomes often have different ____ (1)

Answer 32

alleles

Question 33

Phenotype (def.)

Answer 33

the physical characteristics of a cell/organism (“what we see”)

Question 34

In a heterozygote the _____ allele conceals
the ______allele

Answer 34

-dominant
-recessive

Question 35

describing allele interaction

Answer 35

-The A allele is dominant to the a allele
(must state two alleles)

Question 36

If a cell/organism has a dominant phenotype but we don’t know if it is A / A or A / a?

Answer 36

A/ ___