Pmt Predicted Paper Flashcards
1
Q
Describe what is meant by the term semi conservative replication
A
Each new dna molecule consists of one template strand and one new strand
2
Q
How could a deletion mutation change the active site of an enzyme
A
- 1 base is deleted from the dna base sequence
- entire sequence after deletion is affected (causes a frameshift)
- changes amino acid sequence coding for enzyme
- changes tertiary structure of enzyme
- active site no longer complementary
3
Q
How could a severe deficiency in protein affect the movement of fluid in capillaries
A
- more fluid retained at tissues
- because of lowered oncotic pressure (osmotic) in the capillaries
- because of less proteins in the blood
4
Q
What are the 3 types of adaptation
A
- physiological
- anatomical
- behavioural
5
Q
Describe 2 differences in the structure of the xylem and the phloem
A
- xylem has lignin, phloem does not
- phloem contains sieve plates, xylem does not
6
Q
In what situation would a t test be used?
A
To determine if there is a significant difference between two means
7
Q
What is herd immunity and state the advantages of it
A
When a large proportion of a population are vaccinated against a disease which prevents the spread of disease to unvaccinated individuals
- Can lead to eradication of disease
- Protects vulnerable populations / people who cannot have
vaccine/ named examples e.g. babies - Prevents future pandemics
