Variation and Evolution Chp17 Flashcards
What is classification
placing objects into groups based on similar characteristics
What is taxonomy
the science of classifying organisms
What is a species
a group of similar organisms that are capable of naturally interbreeding with each other to produce fertile offspring
What is variation
different characteristics within the same species
What are acquired variation
variations that are not inherited but are learned or developed during life
Examples of acquired variation
ability to walk, speak a language, ride a bike
What is inherited variation
variation controlled by genes
Examples of inherited variation
eye colour, hair colour, blood type
What causes variation
sexual reproduction and mutation
What is a mutation
a spontaneous change in the amount or structure of DNA
What are mutagens
agents that cause mutations e.g. UV radiation, tobacco smoke, pesticides, gamma rays
What is a gene mutation
a change in a single gene
Example of a gene mutation
sickle cell anaemia
What is sickle cell anaemia
an inherited blood disorder caused by a mutation in the haemoglobin gene
Symptoms of sickle cell anaemia
paleness, weakness, heart failure, severe pains, damage to the brain and other organs and very often death
Treatment for sickle cell anaemia
blood transfusion
What is a chromosome mutation
a large change in the structure of one or more chromosomes
Example of a chromosome mutation
down syndrome
What is evolution
the way in which living things change genetically to produce new forms of life over long periods of time
What is natural selection
the process by which those organisms with genetically controlled characteristics that allow them to be well adapted to their environments will survive and reproduce to pass on their genes to following generations
What are the observations of natural selection
overbreeding, population numbers remain constant, there is a struggle for existence, inherited variations occur in populations and natural selection
What is speciation
the production of new species as a result of evolution
Evidence of evolution
the study of fossils
What is a fossil
the remains of something that lived a long time ago
