Genetics, Genome, Gene Expression, Cell Cycle

Question 1

what is a missense mutation

Answer 1

swapping of nucleotide–> change in codon–>change in amino acid

Question 2

what is the difference between coding strand and non coding strand?

Answer 2

coding strand is the direct sequence that the mRNA will be.

non coding (template) is the complimentary sequence

Question 3

What is alternative splicing?

Answer 3

When splicesome cuts out introns and exon sequence in variety of ways to further produce unique proteins

Question 4

What is the purpose of the poly-A tail and the 5’ cap on the mRNA sequence

Answer 4

The poly A tail is used to prevent degradation of the sequence

5’ cap allows for efficient translation, stabilization and transportation of mRNA in eukaryotes

Question 5

What is the start codon– and starting amino acid in the sequence?

Answer 5

AUG–methionine

Question 6

What are the stop codons ?

Answer 6

UAA
UGA
UAG

Question 7

centromere positions

Answer 7

metacentric– mid

telocentric– outer or end

acrocentric– very different
chromosomal arm lengths

submetacentric– slightly different arm length

Question 8

oncogene, proto oncogene, tumor supressor

Answer 8

oncogene– mutated gene that has potential to cause cancer (onces proto-oncogneic)

tumor suppressor– meant to regulate proliferative capacity of cells

Question 9

what is another name for the sense strand?

Answer 9

coding strand (5–>3)

Question 10

What is the function of DNA polymerase

Answer 10

add nucleotides as 5–>3 however this protein reads the DNA from 3–>5 during DNA replication

Question 11

what is another name for the antisense strand

Answer 11

template strand (3–>5)

Question 12

what does it mean to be aneuploidy

Answer 12

one or more extra OR missing chromosomes

Question 13

what happens if you have aneuploidy?

Answer 13

infertility and inherited birth defects

Question 14

what is a point mutation?

Answer 14

singular base pair in the genome is added or deleted –

cause silent or missense (depending on whether the amino acid sequence changes)

Question 15

X-linked disorders are passed on to which sex?

Answer 15

males

Question 16

what is the consequence to inbreeding?

Answer 16

lower genetic diversity leading to the presence of diseases and mutated genes being present in the off spring

Question 17

how many possible codons are there

Answer 17

4^3=64

Question 18

how many distinct codons can code for amino acids—

Answer 18

4^3=64 minus 3=61 (exclude the stop codons)

Question 19

Trisomy 21 is caused by?

Answer 19

nondisjunction

Question 20

What is the genetic protection behind the G2/M checkpoint

Answer 20

after synthesis or replication there can possibly be DNA damage–

protects the cells from dividing with DNA damages

Question 21

What is DNA gyrase

Answer 21

exist in prokaryotes and some eukaryotes– acts like topoisomerase in prokaryotes.

Question 22

what do cyclins do

Answer 22

initiate processes relating to cellular division

Question 23

lower levels of cdk and cyclins

Answer 23

result in stalling of cellular division and overall stalling of the cell cycle

Question 24

what is a nonsense mutation

Answer 24

mutation which cause a premature truncated protein

Question 25

what is a frameshift mutation

Answer 25

caused by an insertion or deletion causing the reading frame to shift

Question 26

what type of bonds exist between nitrogenous bases

Answer 26

hydrogen bonds
C/G have 3
A/T have 2

Question 27

What are the phases of the cell cycle

Answer 27

G0, G1, S, G2, M

Question 28

What is the quiescents state called in the cell cycle

Answer 28

G0

Question 29

when is a cell committed to undergo mitosis

Answer 29

G1

Question 30

when does crossing over occur

Answer 30

meiosis I (prophase)

Question 31

what is synapsis

Answer 31

fusion of chromsomal pairs at the start of meiosis

Question 32

what protein structure is involved in recombination, pairing and synapsis

Answer 32

synaptonemal complex

Question 33

importance of gamma tubulin

Answer 33

component of centrioles– so spindles will not be formed from the start of mitosis

Question 34

what is the end result of meiosis vs mitosis?

Answer 34

mitosis results in 2n (46)
meiosis results in n (23)

Question 35

what a wobble position

Answer 35

you can change (the last base) to any base and it will be the same amino acid– silent mutations

Question 36

results of spermatogeneisis vs. oogenesis

Answer 36

produces four germ cells vs. one germ and three dark polar bodies

Question 37

describe the stage of spermatogenesis

Answer 37

spermatogenia(2n)–>primary spematocyte (2n)–>secondary spermatocyte (n)–>spermatids(n)

Question 38

the role of plasmids

Answer 38

circular double stranded DNA that serve to provide antibiotic resistance, sex pilus and holding genes beneficial to the host

Question 39

what is elongation in DNA replication

Answer 39

the use of DNA polymerase to add nucleotides to form a daughter strand complementary to the parent strand

Question 40

nucleoside vs nucleotide

Answer 40

nucleoside does not include the triphosphates

Question 41

Does the RNA leave the nucleus before or after modification?

Answer 41

after

Question 42

purpose of splicesome

Answer 42

to allow for diversity of transcripts

Question 43

Transposons

Answer 43

class of genetic elements that can move around throughout the genome

Question 44

Class 1 Transposon

Answer 44

use RNA that is reverse transcribed to reintegrate back into the genome. (copy and paste)

Question 45

Class 2 Transposon

Answer 45

DNA transposons… move gene by cut and paste

Question 46

nondisjuction

Answer 46

failure for chromosomes to separate so you end up with abnormal amound of chromsomes

Question 47

what are linked genes

Answer 47

genes that are close together on the chromosome and during homologous recombination will crossover together