Classification, Heredity, Variation & Evolution Flashcards
Cell Continuity
The ability of cells to divide and survive from one generation to the next
Heredity
The passing on on of characteristics from one generation to the next
Species
A group of organisms capable of interbreeding to produce fertile offspring
Variation
The differences between members of the same species
Gene (a unit of heredity)
A section of DNA (Deoxyribonucleic Acid) that causes the production of a protein
Name & Outline the two types of variation
Acquired - things that are learned e.g. kicking a ball
Inherited - Controlled by genes e.g. Eye/Hair Colour
>Caused by two processes
~ Sexual Reproduction
~ Mutations
Mutations
A mutation is a sudden change in the amount or structure of DNA
Causes/Agents of mutations
UV Radiation
Cigarette Smoke
Viruses
X-Rays
Mutagens
Agents that cause cancer
Types of Mutagens
Gene Mutation
Chromosome Mutation
Gene Mutation
A change in a single gene e.g. Sickle Cell Anaemia or Cystic Fibrosis
> Happens due to a change in a single base pair
Sickle Cell Anaemia (Causes? Symptoms? Cure? Treatment?)
> Causes haemoglobin to take on a curved shape
Suffer from Paleness, weakness, severe pain, heart failure, possible Death
No Cure, treatment > blood transfusions
Chromosome mutation
Large changes in structure or number of chromosomes e.g. Downs Syndrome
Down’s Syndrome
Normally 46 chromosomes in each somatic cell
Down syndrome caused by one extra chromosome, therefore 47 Chromosomes
3 number 21 chromosomes. Fault in meiosis
Physical and mental changes arise due to the extra chromosome
Evolution
Way in which living things in a population change genetically over long periods of time (or in response to environmental changes)
