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Flashcards in Genetics 1 Deck (39)
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1
Q

Garrod

A

new class of human disease based on hereditary factors (inborn errors of metabolism)

2
Q

Mendel

A

father of modern genetics (hybridization of peas)

3
Q

watson and crick

A

double helix DNA

4
Q

human genome project

A

2003, sequence of human genome completed revealing all 3 billion base pairs

5
Q

what does the human genome include

A

human genome encoded on both nuclear and mitochondrial chromosomes contained in the nucleus of somatic cells

6
Q

soma=

A

body

7
Q

how many chromosomes ?

A
46 chromosomes 
(22 pairs of autosomes, 1 pair sex chromosomes)
8
Q

what are homologous chromosomes

A

members of a pair of chromosomes

  • carry matching genetic information
  • same genes in the same sequence
9
Q

what are alleles

A

identical or slightly different forms of the same gene

10
Q

what is a locus

A

specific location of a gene or DNA sequence on a chromosome

11
Q

DNA structure is made up of

A

polymeric nucleic acid macromolecule (nucleotide)

12
Q

what 3 types of units is DNA made of

A
  • 5 carbon sugar (deoxyribose)
  • nitrogen containing base
  • phosphate group
13
Q

purine bases

A
  • adenine (A)

- guanine (G)

14
Q

pyrimidine bases

A
  • cytosine (C)

- thymine (T)

15
Q

DNA polynucleotide chain characteristics

A
  • polymerized (linked, connected together) by 3’-5’ phosphodiester bonds
  • right handed double helix held together by H bonds
16
Q

characteristics of chromosomes

A

complexed with several classes of chromatin proteins (histone and nonhistone proteins)

17
Q

how are chromosomes packaged?

A

as chromatin

18
Q

functional organization and structural organization of genome

A

highly correlates

19
Q

out of 3 billion base pairs of DNA in the genome, how many code for proteins

A

less than 1.5%

20
Q

what percent of base pairs codes for regulatory elements of gene expression

A

about 5%

21
Q

what percent of base pairs in genome codes for so called single-copy or unique DNA

A

half the total linear length of the genome

estimated 25,000 genes in the genome fall under the single copy DNA category

22
Q

what percentage of base pairs in genome code for repetitive DNA

A

about half of the genome

-about half consists of repetitive DNA- involved in maintaining chromosome structure and source of variation

23
Q

mitosis

A
  • ordinary somatic cell division
  • involved with body growth, differentiation, tissue regeneration
  • results in two daughter cell with chromosomes and genes identical to parent cell
  • 2n, diploid
24
Q

meiosis

A
  • involves the cell of the gremlin
  • formation of reproductive cells (gametes)
  • n, haploid
25
Q

interphase=

A

G1 + S + G2

  • period between the 2 mitoses
  • state in which most of the life cycle of a cell is spent
26
Q

phases of cell cycle and how much time in each

A

G1 (10-12 hrs)
S (6-8hrs)
G2 (2-4 hrs)
M (1-2 hrs)

27
Q

G1 phase

A

10-12 hours, up to days to years

  • no DNA synthesis
  • neurons and RBC get arrested in this state of differentiation
28
Q

S phase

A

6-8 hours

  • DNA synthesis
  • replication to form 2 sister chromatids
29
Q

G2 phase

A

2-4 hours

-doubling of total mass

30
Q

M phase

A

mitosis

1-2 hours

31
Q

mitosis

prophase

A
  • initiation of mitosis

- condensation of chromosomes, formation of mitotic spindles an centrosomes

32
Q

mitosis

prometaphase

A
  • breakup of nuclear membrane
  • establish connection to kinetochores
  • chromosomes begin to congregate midway
33
Q

mitosis

metaphase

A
  • chromosomes reach maximum condensation

- arranged and lined up at the equator

34
Q

mitosis

anaphase

A
  • chromosomes separate at the centromere
  • sister chromatid become separate and independent
  • movement to opposite poles
35
Q

mitosis

telophase

A
  • decondense

- nuclear membrane begins to reform

36
Q

meiosis is

A

cell division that involves the germ line

-whereby diploid cells give rise to haploid gametes

37
Q

meiosis consists of

A
  • 1 round of DNA synthesis and 2 rounds of chromosome segregation and cell division
  • meiosis I and meiosis II
38
Q

meiosis I and II

A

meiosis I is reduction division- chromosome number is halved
-recombination (meiotic crossover) occurs
meiosis II is ordinary mitosis

39
Q

recombination

A

(meiotic crossover) homologous segments of DNA are exchanged between non-sister chromatids of a pair of homologous chromosomes