DNA and Cell Division Flashcards
1
Q
Nucleus; Russian doll?
A
Nucleus -> chromosomes -> genes
2
Q
How is a chromosome divided?
A
Into many genes
3
Q
How do chromosomes normally occur?
A
Functional pairs
4
Q
DNA
A
Deoxyribonucleic acid
5
Q
A gene
A
A short length of DNA that codes for a particular protein or characteristic
6
Q
Genome
A
All the DNA in an individual
7
Q
Three sub-units of DNA
A
- Sugar (deoxyribose)
- phosphate
- bases
8
Q
Sugar in DNA
A
Deoxyribose
9
Q
Four different types of base
A
- adenine
- guanine
- cytosine
- thymine
10
Q
How is DNA constructed?
A
- DNA is constructed like a ladder
- sides are formed from sugar and phosphate units
- rungs of the ladder are bases
- bases link the two sides together
- the DNA ladder is twisted round on itself to form a double helix
11
Q
Nucleotide
A
Each reacting unit of DNA (consisting of a phosphate, a sugar and a base)
12
Q
Base pairing
A
Adenine - thymine
Guanine - cytosine
