Genetics 1

Question 1

Garrod

Answer 1

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

Question 2

Mendel

Answer 2

father of modern genetics (hybridization of peas)

Question 3

watson and crick

Answer 3

double helix DNA

Question 4

human genome project

Answer 4

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

Question 5

what does the human genome include

Answer 5

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

Question 6

soma=

Answer 6

body

Question 7

how many chromosomes ?

Answer 7

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

Question 8

what are homologous chromosomes

Answer 8

members of a pair of chromosomes

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

Question 9

what are alleles

Answer 9

identical or slightly different forms of the same gene

Question 10

what is a locus

Answer 10

specific location of a gene or DNA sequence on a chromosome

Question 11

DNA structure is made up of

Answer 11

polymeric nucleic acid macromolecule (nucleotide)

Question 12

what 3 types of units is DNA made of

Answer 12

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

Question 13

purine bases

Answer 13

• adenine (A)

- guanine (G)

Question 14

pyrimidine bases

Answer 14

• cytosine (C)

- thymine (T)

Question 15

DNA polynucleotide chain characteristics

Answer 15

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

Question 16

characteristics of chromosomes

Answer 16

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

Question 17

how are chromosomes packaged?

Answer 17

as chromatin

Question 18

functional organization and structural organization of genome

Answer 18

highly correlates

Question 19

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

Answer 19

less than 1.5%

Question 20

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

Answer 20

about 5%

Question 21

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

Answer 21

half the total linear length of the genome

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

Question 22

what percentage of base pairs in genome code for repetitive DNA

Answer 22

about half of the genome

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

Question 23

mitosis

Answer 23

• 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

Question 24

meiosis

Answer 24

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

Question 25

interphase=

Answer 25

G1 + S + G2 - period between the 2 mitoses - state in which most of the life cycle of a cell is spent

Question 26

phases of cell cycle and how much time in each

Answer 26

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

Question 27

G1 phase

Answer 27

10-12 hours, up to days to years - no DNA synthesis - neurons and RBC get arrested in this state of differentiation

Question 28

S phase

Answer 28

6-8 hours - DNA synthesis - replication to form 2 sister chromatids

Question 29

G2 phase

Answer 29

2-4 hours | -doubling of total mass

Question 30

M phase

Answer 30

mitosis | 1-2 hours

Question 31

mitosis | prophase

Answer 31

- initiation of mitosis | - condensation of chromosomes, formation of mitotic spindles an centrosomes

Question 32

mitosis | prometaphase

Answer 32

- breakup of nuclear membrane - establish connection to kinetochores - chromosomes begin to congregate midway

Question 33

mitosis | metaphase

Answer 33

- chromosomes reach maximum condensation | - arranged and lined up at the equator

Question 34

mitosis | anaphase

Answer 34

- chromosomes separate at the centromere - sister chromatid become separate and independent - movement to opposite poles

Question 35

mitosis | telophase

Answer 35

- decondense | - nuclear membrane begins to reform

Question 36

meiosis is

Answer 36

cell division that involves the germ line | -whereby diploid cells give rise to haploid gametes

Question 37

meiosis consists of

Answer 37

- 1 round of DNA synthesis and 2 rounds of chromosome segregation and cell division - meiosis I and meiosis II

Question 38

meiosis I and II

Answer 38

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

Question 39

recombination

Answer 39

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