DNA

Question 1

What is in a nucleotide

Answer 1

A sugar base and phosphate group

Question 2

Key features of a polynucleotide

Answer 2

Nucleotides are joine together by phosphdiester bonds
The chain has polarity 5’ to 3’
The chain has distinct ends 5’ ( phosphate end) and 3’ (sugar end)

Question 3

Polynucleotide secondary strucutre

Answer 3

Nucleic acids can form duplex structure
Strands are complementary
Strands are a itparrellel
Can have DNA-DNA, RNA-RNA strands and DNA-RNA strands

Question 4

What is in a nucleoside

Answer 4

A base and sugar

Question 5

describe how DNA is packaged

Answer 5

double helix 
nucleosomes 
solenoids 
solenoid loops 
chromosomes

Question 6

Define genome

Answer 6

the entire DNA sequence

Question 7

give four key features of DNA replication

Answer 7

needs separation fo DNA strands
occurs in a step wise reaction
reaction driven by pyrophosphate hydrolysis
chain gortwh is directional from 5 to 3’

semi conservative

Question 8

what are the consequences of meiosis

Answer 8

maintain constant chromosome number from generation to generation

creates genetic diversity from random assortment and crossing over

Question 9

what is the role of meiosis

Answer 9

production of four non identical cells with half the chromosome content of partent cell

diploid cell is reduced to haploid cell

special cell division for germ line cells

Question 10

describe a mistake in meiosis

Answer 10

the chromosomes do no segregate properly

can cause miscarriages
infertility
mental retardation