Test One Flashcards
Pg (7-)
All the snails are different.
What scientific term describes differences in characteristics between individuals of a
species?
Variation
A change in DNA has caused the snail to be very different from the other five snails.
Suggest why there might be an increasing number of snails similar to snail P in each
future generation.
Stronger shell
Larger shell
Cigarette smoking is the main cause of cancer in the UK.
Mutations in cells cause cancer.
Where in a cell do mutations happen?
- Nucleus
- More likely to (survive and) breed
- More likely to (survive and) pass on genes
Why do some cancers develop into large tumours?
Cells never stop dividing
Cigarette smoking has been linked to many different types of cancer.
Lung cancer is the most common type of cancer caused by smoking.
Suggest one reason why.
- chemicals enter the lungs (first)
- chemicals are inhaled
A person with lung cancer can develop secondary cancers in other parts of the
body.
Describe how this can happen.
- Cancer cells transported in the blood
Sometimes a person may need a lung transplant.
The National Health Service (NHS) will not offer a lung transplant to a person who
smokes.
Suggest one reason why.
- Smoking will damage the new lung
- Allow wastes a healthy lung
Survival rates for all types of cancers have improved over the last 20 years.
Suggest two reasons why.
- improved treatment/drugs
- earlier diagnosis
Describe the structure of DNA.
- Polymer
- Double Helix
Sperm cells are male gametes.
What are female gametes called?
- egg(s)
- ova
Describe one difference between the chromosomes in a sperm cell and the
chromosomes in a liver cell.
- Liver cells contain pairs of chromosomes
- Sperm cells are haploid and liver cells are diploid
Explain why a bacterium can rely on diffusion for gas exchange, but animals need a
transport system.
- Animal has a small(er) surface area to volume ratio (than a bacterium)
