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Biology

GCSE · AQA

QuestionsFlashcards

Communicable Diseases
Monoclonal Antibodies
- Producing Monoclonal Antibodies
  6
- Uses of Monoclonal Antibodies
  7
Plant Disease
- Detection and Identification of Plant Diseases
  6
- Plant Defence Responses
  6

Variation Flashcards

All 7 cards in this deck

What is variation?: Differences in the characteristics (phenotypes) of individuals of the same species, caused by genes, the environment, or a combination of both. There is usually extensive genetic variation within a population.
How do the genome and the environment together produce an organism's phenotype? e.g. the height of a tomato plant: The genome sets which characteristics can develop, and the environment affects how they actually develop.

e.g. genes set the possible height, but light, water and minerals decide the actual height.
True or false? Two genetically identical plants grown in the same garden must grow to the same height.: False. Environmental differences (light, water, minerals, soil pH, disease, herbivores) change the phenotype.
What is a mutation?: A change in the DNA (base sequence), which may change a gene or allele.
What effect do mutations have on the phenotype?: Most have no effect on the phenotype, some influence it, and very rarely a mutation leads to a new phenotype. Mutations occur continuously.
When can a single mutation lead to a relatively rapid change in a species?: When the new phenotype it produces is suited to an environmental change.
True or false? There is usually extensive genetic variation within a population of a species.: True. Mutations occur continuously, so members of a species differ widely in their alleles.