m&m

Question 1

what is DNA

Answer 1

double stranded, helical molecule found within nucleus of each cell

carries genetic information that codes for proteins which are necessary for cells to reproduce and perform their functions

Question 2

structure of chromatin

Answer 2

when not-dividing, the chromosome exists in its uncondensed form in a long, thin, thread-like fibres known as chromatin

Question 3

what is chromatin

Answer 3

complex of DNA and histone proteins

Question 4

what is the level of association of DNA with histone proteins in chromatin

Answer 4

DNA winds around an octamer formed by 8 histone proteins to form a nucleosome

adjacent nucleosomes are linked by linker DNA and further condenses by coiling/folding many times upon itself to form a chromosome that will appear as a shorter, thicker and more visible structure

Question 5

define diploid

Answer 5

term used to describe a nucleus, cell or organism with two complete sets of chromosomes

chromosomes exist as homologous pairs where each chromosome of the pair comes from either parent –> bears the ancestral genes that represent maternal and paternal family lines

Question 6

define haploid

Answer 6

term to describe when a nucleus, cell, or organism only has one complete set of chromosomes

Question 7

characteristics of homologous choromosomes

Answer 7

1. same genes as corresponding loci
2. one homologou originates from male and other from female parent
3. similar in size, shape, staining pattern, centromere psoition
4. may not be identical in what they code for

Question 8

define homologous chromosomes

Answer 8

two chromosomes with similar shape, size, staining pattern, centromere position and position of genes in a diploid cell

Question 9

describe interphase’s main events

Answer 9

1. period of synthesis and growth
2. production of organelles and materials required for carrying out its functions
3. replication of DNA to prepare for nuclear division

Question 10

cell cycle stages (3)

Answer 10

90% interphase, nuclear division, cytokinesis (division of cytoplasmic contents into 2 daughter cells)

Question 11

G1 phase events

Answer 11

intensive cellular synthesis of organelles (inc RNA, organelles, protein, ATP)

Question 12

S phase (synthesis)

Answer 12

DNA replication ooccurs where DNA molecules replicate so that DNA content of cell doubles

Question 13

G2 phase events

Answer 13

intensive cellular synthesis of organelles, spindle proteins, ATP (in preparation for mitosis)