3 - The Cell & DNA Flashcards
1
Q
Problem of blending inheritance
A
Dilutes and eventually eliminates variation
2
Q
Mitosis
A
Creates two exact copies of chromosome pairs (diploid)
3
Q
Meiosis
A
- Gametes
- Creates single chr
4
Q
Two complex molecules chromosomes contain
A
- Proteins (histones)
- Nucleic acid (DNA)
5
Q
Gene
A
- Segment of DNA that makes a functional product and segregates as a unit during gamete formation
- Composed of introns and exons
6
Q
Enzymes
A
- Catalyse chemical
reactions in cells - E.g. amylase, rennin, cellulase
7
Q
Non enzymatic proteins
A
e.g. keratin, collagen, histones
8
Q
Regulatory sequences
A
- DNA sequences that
determine if/when other protein-coding sequences are expressed - Non-coding, but near the protein-coding sequence
- Usually binding sites for repressor or activator proteins
- Large source of phenotypic variation
9
Q
How does variation arise
A
Due to differential regulation of the same DNA among cells (e.g. bone vs heart cell)
10
Q
IMportant sources of variation
A
- Mutation
- Crossing over / recombination
