L1

Question 1

2 challenges in organization of genomes

Answer 1

1. Packaging of DNA - genome length 1 meter. nucleus 6um.

2. Cell division - how to ensure each daughter cell gets one copy of the DNA

Question 2

size difference of PK and EK cell

Answer 2

PK - 10um

EK - 100um

Question 3

how many cells in adult human

Answer 3

10^13

Question 4

basic organization of genome

Answer 4

duplex DNA
Wound around histones (nucleosomes)
Solenoid - 30nm
loose chromosome
Condensed chromatin
Mitotic chromosome

Question 5

eu/heterochromatin

Answer 5

Eu - loosely coiled - in transcription

Hetero - tightly wound, suppressed genes

Question 6

what causes chromosome banding? how can it be seen?

Answer 6

Due to base composition and chromosome loop structure.
Seen using Giemsa stains - G banding.
Dark regions are heterochromatin

Question 7

what is FISH

Answer 7

Fluorescence in situ hybridization

probe oligonucleotide sequence labelled with fluorescent dye is hybridized to a chromosome.

Question 8

what is a karyotype

Answer 8

structures of individual chromosomes in an individual.
constant for individuals of the same species, differs between species. Result of chromosome rearrangements in evolution. this is a barrier to interspecific breeding.

Question 9

No. chr in human

Answer 9

46

Question 10

what is the C value?

Answer 10

amount, in pictograms, of DNA in a haploid nucleus

or one half the amount in a diploid somatic cell of a eukaryotic organism.

Question 11

how many bp in a mega base?

Answer 11

1 million

Question 12

giga base pairs

Answer 12

1000,000,000 bp

Question 13

what is the C value paradox?

Answer 13

genome size doesn’t scale with complexity

Question 14

how many bp in human genome?

Answer 14

3 billion