Lecture 1 Intro/fundamentals Flashcards Preview

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Flashcards in Lecture 1 Intro/fundamentals Deck (31)
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1
Q

of chromosomes in a human?

A

46 total

23 pairs

2
Q

what is a proteome?

A

complete set of proteins encoded by genome

3
Q

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

A

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

4
Q

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

A

risk of developing disease (not 100% predictive);

ApoE in alzheimers, BRCA1 and 2 in breast cancer

5
Q

what does ELSI stand for

A

ethical, legal, and social implications

6
Q

50% of first trimester abortions are due to what?

A

chromosomal disorders

7
Q

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

A

semi-conservative;

5, 3

8
Q

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

A

G-C;

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

9
Q

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

A

8 positively

10
Q

somatic cells have ____ chromosomes and are ____ploid;

gametes have ____ chromosomes and are ___ploid

A

46, diploid;

23, haploid

11
Q

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

A

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

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

12
Q

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

A

telomeres;

telomerase (adds DNA to 3’ ends of chromosomes)

13
Q

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

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

A

exons;
introns;

5’

14
Q

the ____ strand of DNA is the template for transcription.

where does transcription occur?

A

anti-sense;

in the nucleus

15
Q

where does translation occur?

what end of mRNA does it start with?

A

cytoplasm;

5’ end

16
Q

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?

A

silent;
non-sense;
missense;
frame-shift

17
Q

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

A

1, 1;
2

ie gives rise to 2 identical sister chromatids

18
Q

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

A

mitosis (rest = interphase and not really visible)

19
Q

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

A

condensation, spindle;

prometaphase, kinetochores

20
Q

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

A

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

"metaphase = MEET"
"anaphase = AWAY"
21
Q

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

A

spindle assembly checkpoint; unequal

22
Q

cell cycle in always dividing cells:

mitosis –> ______ –> ____ –> ____

A

G1, S phase, G2

23
Q

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

A

1, 2;

1 (ie 23 chromosomes)

24
Q

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

A

meosis 1 ;

meiosis prohpase 1, after (ie 4 strand stage)

25
Q

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

meiosis2 =
_____ division; sister chromatids separate

A

reductional;

equatorial (like mitosis)

26
Q

what holds homologs/sister chromatids together in M1?

A

cohesin complex aka chiasmata

27
Q

chromosome non disjunction occurs if:

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

chiasmata;

crossing over

28
Q

spermatogenesis begins at _____.

A

puberty

29
Q
oogenesis:
meiosis begins when?
what phase is meiosis arrested in?
what is this called?
meosis II is arrested in \_\_\_\_ until \_\_\_\_\_
A

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

30
Q

ovulation:

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

spindle;
MII spindle;
polar body

31
Q

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

A

3.

1 ovum