MEGA Final Deck

Question 1

when does crossing over occur

Answer 1

prophase I

Question 2

when does independent assortment occur

Answer 2

metaphase I

Question 3

when does disjunction occur

Answer 3

anaphase (meiosis + mitosis)

Question 4

sex-linked traits

Answer 4

appear on X chromosomes

Question 4

quantitative traits

Answer 4

determined by many genes + exhibit continuous variation (e.g. height)

Question 5

XX mosaic/inactivation

Answer 5

only occurs in females, heterozygous where only one X is active alternatingly (paternal/maternal X take turns being active)

Question 6

incomplete dominance

Answer 6

traits blend (red + white = pink)

Question 7

co-dominance

Answer 7

both traits show (red + white = red + white)

Question 8

TATA box

Answer 8

region of the promoter with a lot of Ts + As to tell the cell the direction + location to start transcription

Question 9

enhancers

Answer 9

far away regions from transcription site that can up-regulate (promote) transcription

Question 10

activators

Answer 10

proteins bind to enhancers + promote transcriptions

Question 11

polymerase II

Answer 11

creates RNA strand in trasncription

Question 12

transcription unit

Answer 12

region of DNA that is transcribed

Question 13

mediator complex

Answer 13

links/regulates transcription factors and enhancers to RNA polymerase II together

Question 14

transcription factors

Answer 14

proteins that bind to the promoter + help RNA polymerase bind to DNA

Question 15

transcription regulations + definition (2)

Answer 15

(1) histone acetylation- add acetyl group that loosens chromatin
(2) DNA methylation- add methyl group that tightens chromatin

Question 16

alternative splicing

Answer 16

remove + keep different introns and exons for different proteins; contribute to proteome > genome

Question 17

5’ G cap functions (2)

Answer 17

protects mRNA from degradation + location where mRNA binds to ribosome

Question 18

poly-A tail function (1)

Answer 18

protects mRNA from degradation

Question 19

types of point mutation + definitions (3)

Answer 19

(1) silent- codes for same amino acid
(2) missense- codes for different amino acid
(3) nonsense- codes for STOP codon (THE WORST)

Question 20

genetic code is __ (3)

Answer 20

(1) specific- codon -> 1 amino acid
(2) redundant- multiple codons can code for the same amino acid
(3) nearly universal- across species

Question 21

types of post-translation modification (7)

Answer 21

(1) glycoslyation- add sugar molecule
(2) methylation- add methyl group
(3) acetylation- add acetyl group
(4) phosphorylation- add phosphate group
(5) acid/base
(6) rough ER/ golgi apparatus
(7) hydrolysis- breaks peptide bonds

Question 22

G1 checkpoint checks if __ and moves the cell to __ or __

Answer 22

Cell is big enough to begin DNA replication; G0; S

Question 23

S checkpoint checks if __

Answer 23

DNA replication is complete and accurate

Question 24

G2 checkpoint checks if __

Answer 24

Cell has doubled the quantity of chromatin and organelles

Question 25

M checkpoint checks if __

Answer 25

Chromosomes consist of two chromatids attached at the centromere

Question 26

prophase (3)

Answer 26

(1) chromatin condenses into chromosomes (2) mitotic spindles start to form (3) nucleolus disappears

Question 27

prometaphase (1)

Answer 27

mitotic spindles attach to kinetochores

Question 28

metaphase (2)

Answer 28

(1) chromosomes lines up @ metaphase plate (2) spindle complete

Question 29

anaphase (1)

Answer 29

- sister chromatids separated into daughter chromosomes + moved to opposite poles

Question 30

telophase (2)

Answer 30

- daughter nuclei forming -cytokinesis typically begins

Question 31

cytokinesis (2)

Answer 31

- dividing of the PM - cleavage furrow (animal); cell plate (plants)

Question 32

proto-oncogenes (3 examples) + oncogenes definition

Answer 32

proto-oncogenes- code for positive cell regulators EX: transcription factors, growth factors, cyclins + CDKs oncogenes- mutated (cancer)

Question 33

tumor suppressant genes

Answer 33

code for negative cell regulators [in cell division]

Question 34

aminoacyl-tRNA synthase

Answer 34

enzyme that cataylzes pairing of tRNA to amino acid

Question 35

wobble

Answer 35

flexible pairing @ 3rd base of a codon, allows tRNAs to bind to more than one codon

Question 36

cyclins

Answer 36

family of proteins that activate a specific kinase (CDK); peak @ different cell cycle phases

Question 37

CAM plants

Answer 37

fix CO2 into organic acids during night

Question 38

C4 plants

Answer 38

fix CO2 into mesophyll cells before it enters Calvin Cycle in the bundle sheath cells (minimizes water loss + photorespiration)

Question 39

photorespiration

Answer 39

RuBP combines w/ O2 instead of CO2, releasing CO2 + wasting energy + RuBP

Question 40

DNA is (positively/negatively) charged due to the __ groups

Answer 40

negatively; phosphate