Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > Intro to medical genetics > Flashcards

Intro to medical genetics Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Genome, DNA

A

an organisms total DNA content. DNA=contains the genetic information needed to specify all aspects of embryogenesis, development, growth, metabolism, and reproduction-what makes us functional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

diploid

A

organism that carries two genome copies. 2n=46

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

haploid

A

any cell that has 1n=23. Germ cells or gametes carry a single copy of the genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

human genome contained w/in nucleus:

A

22 autosomes and 2 sex chromosomes, x and y. additionally, DNA is also contained in the mitochondria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Genes

A

sequences of base pairs that encode info for proteins, found on chromosomes. Range from <100 to several million bps.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

exon

A

coding sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

intron

A

non-coding sequence b/w two exons . . . regulatory element

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Regulatory elements

A

HRE-hormone responsive elements
Promoters-always at 5’ end of gene, followed by introns and exons.
Enhancers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

General features of a chromosome: Centromere

A

Centromere:repetetive sequences. Primary constriction on a chromosome-sister chromatids are held together here and kinetochore is formed. Attaches to mitotic spindle so chromosomes properly aligned during mitosis and meiosis and required for proper segregation of chromosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

General features of a chromosome: Telomere

A

the end of each chromosome arm. human telomeres end with tandem copies of TTAGGG, which is required for the proper replication of chromosome ends. Specialized Repetetive seqs of DNA-ensure integrity of chromosome during cell division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

General features of a chromosome: p and q arm

A

p=”petite” or short arm, q= long arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Locus

A

location in the genome of a gene or genetic marker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

alleles

A

alternative forms of a gene or a genetic marker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

heterozygous

A

2 diff alleles at a locus (a,b)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

homozygous

A

2 identical alleles at a locus (a,a)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

haplotype

A

series of alleles on a single chromosome-likelihood to inherit one or the other haplotype from a parent is 50%. All alleles present on a single chromosome are referred to as haplotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

germline

A

cells that develop into gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

somatic cells

A

all cells that contribute to one’s body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

autosomes

A

22 pairs of chromosomes that are alike in males and females.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

sex chromosomes

A

2 X in females; X,Y in males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

homologous chromosomes/homologues

A

members of a pair of chromosomes; carry matching genetic information-they have the same genes in the same sequence; but may have different alleles

22
Q

alleles

A

identical or slightly different forms of the same gene. alternate forms of genes, multiple varieties coding for similar proteins

23
Q

Phenotype

A

Gene expression:observable characteristics:
physical
biochemical
disease status

24
Q

Cell cycle: how many chromosomes does a cell have entering mitosis?

A

4n=92

25
Q

Cell cycle

A

G1: Growth phase, immediately after mitosis; each cell has 1 diploid copy of genome.
G0: Arrested, non-dividing phase, neurons, rbc’s; liver cells-but not permanent
S: Synthesis, DNA content has doubled; each cell now contains 2 copies of the diploid genome. 4n=92
G2: Growth, ribonucleic acids, proteins are produced and cell enlarges->dbl mass before mitosis.

26
Q

Interphase

A

G1, S, G2 phases together constitute interphase

27
Q

Mitosis

A

occurs during cell division of somatic cells.
Diploid cell generates identical diploid cell.
No recombination (normally)

28
Q

Stages of Mitosis: Prophase

A

initiates mitosis, condensation of chromosomes and formation of mitotic spindle. Centrosomes,microtubule organizing centers, form foci from which microtubules radiate.

29
Q

Stages of Mitosis: Prometaphase

A

nuclear memb breaks up; chromosomes disperse and attach via kinetochores to microtubules of mitotic spindle. Congression: chromes move towards mid-point b/w spindle poles.

30
Q

Stages of Mitosis: Metaphase

A

chromosomes reach max condensation; alligned at equatorial plane of cell.

31
Q

Stages of Mitosis: Anaphase

A

Chromes separate at centromere->sister chromatids become independent daughter chromosomes, moving to opposite poles of the cell.

32
Q

Stages of Mitosis: Telophase

A

Chromes decondense, nuclear membrane reforms around each daughter nuclei and gradually resumes it’s interphase appearance.

33
Q

Stages of Mitosis: Cytokinesis

A

Cytoplasm cleaves, completing the process of cell division-> 2 complete daughter cells containing all genetic info of original cell.

34
Q

Meiosis

A

Occurs during gamete formation; a diploid progenitor cell generates four haploid gametes; 1 round of DNA synthesis followed by 2 rounds of chromosome segregation and cell division. Recombination frequent; has 2 phases: meiosis I, II are two successive meiotic divisions.

35
Q

Recombination

A

Exchange of genetic material b/w homologous chromosomes. must be b/w paired chromosomes, any other exchange can lead to mutation

36
Q

Meiosis I

A

aka “reduction division”-chromosome # is halved (2n->n) through pairing of the homologues in prophase followed by segregation to diff cells at anaphase. Recombination/crossing over occurs here

37
Q

Meiosis II

A

1 chromatid from each chromosome passes to daughter cell.

38
Q

Prophase I

A

chromes begin to condense; homologues pair and crossing over occurs->recombinant chromes. Chromes continually condense and become shorter and thicker during all 5 phases of prophase I

39
Q

Prophase I: Leptotene

A

chromes (already replicated during preceding S phase) condense; closely aligned-> indistinguishable. Form pairs of chromosomes(bivalents) consisting of 4 chromatids(tetrads)

40
Q

Prophase I: Pachytene

A

crossing over b/w pairs of homologous chromes to form chiasmata-point holding together 2 bivalents/tetrads which is the location of crossovers.

41
Q

Chiasmata

A

actual location of crossovers. 2 homologues of each bivalent are held together at this point.

42
Q

Prophase I: Diplotene

A

homologous chromes start to separate but remain attached by chiasmata. After recombination; synaptonemal complex begins to break down.

43
Q

Prophase I: Diakinesis

A

homologous chromosomes continue to separate, the chiasmata move to the ends of the chromes. Chromes meet max condensation.—> by telophase I the 2 haploid sets of chromosomes have normally grouped at opposite poles and the cell divides into 2 haploid daughter cells and enters meiotic interphase and meiosis II soon follows. *No S phase b/w the 1st and 2nd meiotic divisions.

44
Q

Meiosis II

A

n=23 chromosomes from reduction division. The 2 daughter cells from meiosis I divide to form 4 haploid cells, each containing 23 chromosomes. Similar to mitosis

45
Q

Meiosis II: Prophase II

A

chromosomes begin to condense and nuclear membrane dissolves, spindle fibers form.

46
Q

Meiosis II: Metaphase II

A

spindle fibers attach to chromosomes and they line up in center of cell.

47
Q

Meiosis II: Anaphase II

A

Centromeres divide and sister chromatids move to opposite ends of cell as spindle fibers shorten

48
Q

Meiosis II: Telophase II

A

Chromosomes reach opposite ends, nuclear membrane forms–>cytokinesis

49
Q

Spermatogenesis

A

Takes place after puberty in testes. Spermatozoa are formed in the seminiferous tubules after sexual maturity.

50
Q

Oogenesis

A

Begins during prenatal development.
-Diplotene arrest-oogenesis is arrested, incomplete–> will be completed in puberty under hormonal stimulation; primary oocyte–> secondary oocyte.
Metaphase arrest-2nd arrest during puberty at metaphase; will only be completed if there is fertilization. *chromosome abns more common in aging mothers b/c cells are arrested longer in diplotene.

Genetics (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions