Lecture 1 Intro/fundamentals

Question 1

of chromosomes in a human?

Answer 1

46 total

23 pairs

Question 2

what is a proteome?

Answer 2

complete set of proteins encoded by genome

Question 3

presymptomatic genetic testing:
looks for genetic mutations rhat are highly _____.
they have a high ____.
example = _______

Answer 3

predictive of developing a disease (near 100%);
penetrance;
Huntington disease

Question 4

susceptibility testing:
look for genetic mutations that confer a high ____
2 examples

Answer 4

risk of developing disease (not 100% predictive);

ApoE in alzheimers, BRCA1 and 2 in breast cancer

Question 5

what does ELSI stand for

Answer 5

ethical, legal, and social implications

Question 6

50% of first trimester abortions are due to what?

Answer 6

chromosomal disorders

Question 7

DNA replication is a ______ process that occurs in the ___ to ____ direction

Answer 7

semi-conservative;

5, 3

Question 8

which DNA base pair has a higher melting temperature? why?

Answer 8

G-C;

it has 3 H bonds vs A-T (which as 2 bonds)

Question 9

a nucloeosome is made of DNA wrapped around ____ _____ charged histones

Answer 9

8 positively

Question 10

somatic cells have ____ chromosomes and are ____ploid;

gametes have ____ chromosomes and are ___ploid

Answer 10

46, diploid;

23, haploid

Question 11

where is the centromere located in….
metacentric chromosomes?
acrocentric chromosomes?

Answer 11

in the middle (ie p and q arm are equal);

at one of the ends (ie v small short arm (p arm))

Question 12

as cells divide, ____ begin to shorten. what prevents this?

Answer 12

telomeres;

telomerase (adds DNA to 3’ ends of chromosomes)

Question 13

exons vs introns:
which are coding sequences?
which are non-coding segments?

are promoters located at the 5’ or 3’ end of genes?

Answer 13

exons;
introns;

5’

Question 14

the ____ strand of DNA is the template for transcription.

where does transcription occur?

Answer 14

anti-sense;

in the nucleus

Question 15

where does translation occur?

what end of mRNA does it start with?

Answer 15

cytoplasm;

5’ end

Question 16

mutations:
nucleotide substitution, codes for same AA = ___;
nucleotide sub, forming an early stop codon = ____;
nucleotide sub, forming a different AA = ____;
what mutation is considered the most damaging?

Answer 16

silent;
non-sense;
missense;
frame-shift

Question 17

mitosis:
____ replication(s) and ____ cell division(s);
cells end up being __n

Answer 17

1, 1;
2

ie gives rise to 2 identical sister chromatids

Question 18

during what phase of the cell cycle are chromosomes typically visible?

Answer 18

mitosis (rest = interphase and not really visible)

Question 19

mitosis:
prophase = ____ of chromosomes and formation of _____.
____: nuclear membrane dissolves, _____ attach to spindle

Answer 19

condensation, spindle;

prometaphase, kinetochores

Question 20

mitosis:
metaphase =
anaphase =
telophase = chromosomes begin to ____, nuclear membrane reforms

Answer 20

chromosomes line up at equatorial plate ;
chromosomes separate at centromeres;
de-condense

"metaphase = MEET"
"anaphase = AWAY"

Question 21

the ____ regulates the metaphase to anaphase transition. it prevents _____ chromosome segregation

Answer 21

spindle assembly checkpoint; unequal

Question 22

cell cycle in always dividing cells:

mitosis –> ______ –> ____ –> ____

Answer 22

G1, S phase, G2

Question 23

meosis:
___ replication phase(s), ____ division phase(s);
final products are ___n

Answer 23

1, 2;

1 (ie 23 chromosomes)

Question 24

meiosis:
homologs segregate during ____.
crossing over occurs during _____. is this before or after replication?

Answer 24

meosis 1 ;

meiosis prohpase 1, after (ie 4 strand stage)

Question 25

meiosis 1 = _____ division, ie homologous centromeres separate at anaphase 1;

meiosis2 =
_____ division; sister chromatids separate

Answer 25

reductional;

equatorial (like mitosis)

Question 26

what holds homologs/sister chromatids together in M1?

Answer 26

cohesin complex aka chiasmata

Question 27

chromosome non disjunction occurs if:

1. no ____ formation
2. _____ at sub-optimal location ie v far away from centromere

Answer 27

chiasmata;

crossing over

Question 28

spermatogenesis begins at _____.

Answer 28

puberty

Question 29

oogenesis:
meiosis begins when?
what phase is meiosis arrested in?
what is this called?
meosis II is arrested in \_\_\_\_ until \_\_\_\_\_

Answer 29

during fetal life;
prophase 1;
dictyotene;
metaphase 2, fertilization

Question 30

ovulation:

1. ____ forms, homologs separate
2. one set of homologs will assemble on the ___ ___
3. other homolog is ejected and is now called a _____

Answer 30

spindle;
MII spindle;
polar body

Question 31

for one primary oocyte, how many polar bodies are formed?

Answer 31

3.

1 ovum