Nero notes - Lectures 1&2

Question 1

Genome size

Answer 1

the total amount of DNA contained within 1 copy of a single genome • variation in genome size is not proportional of the number of genes

Question 2

Variation in genome size

Answer 2

is not proportional to the number of genes

Question 3

Ploidy

Answer 3

the number of sets of chromosomes in a cell • ant species Mymercia pilosula - a haploid species 2n=2 –> n=1

Question 4

Haplodiploid

Answer 4

sex determination system • males - from unfertilized eggs, haploid • females - from fertilized eggs, diploid

Question 5

Diploid

Answer 5

contain 2 complete sets of chromosomes 2n

Question 6

Haploid

Answer 6

contain only 1 complete set of chromosomes n

Question 7

C value

Answer 7

the amount of DNA within a haploid nucleus • half the amount of DNA in a diploid somatic cell • C value paradox - puzzle surrounding the extensive variation in nuclear genome size among eukaryotic species

Question 8

Genome size doesn’t correlate with

Answer 8

organism complexity • some single-celled protists have genomes that are larger than humans

Question 9

Aneuploidy

Answer 9

having a chromosome number that’s not an exact multiple of haploid number • difference in individual chromosome numbers • due to nondisjunction of chromosomes (in mitosis - the failure of sister chromatids to separate during and after mitosis) - eg down syndrome

Question 10

Nondisjunction

Answer 10

failure of sister chromatids to separate during and after mitosis

Question 11

Polyploidy

Answer 11

when a cell contains more than 2 sets of chromosomes • whole genome duplication

Question 12

Ideograms

Answer 12

used as a standard representation of chromosomes