Yr 8 Variation Test Flashcards
(28 cards)
allele
-different forms of a gene
biodiversity
-a measure of the variety of all the different species of plants/animals on earth (or within a particular habitat)
captive breeding
-breeding animals in human-controlled environments
chromosome(s)
-thread-like structure containing tightly coiled DNA
-it contains many genes
competition
-when 2+ struggle against each other to get the same resource
conservation
-protecting a natural environment, to ensure that habitats are not lost
dominant allele
-a dominant allele will always be expressed if it is present
endangered species
-a species with only small numbers of organisms left in the world
evolution
-theory that the animal and plant species living today descended from species that existed in the past
extinct
-when no more individuals of a species remain anywhere in the world
fossil
-the remains or traces of plants and animals that have turned to stone
gene
-a section of DNA that determines an inherited characteristic
gene bank
-a store of genetic samples, used for research and to try to prevent extinction
genetic modification
-a technique in which scientists insert foreign genes into organisms to change their characteristics
inherited characteristics
-features that are passed from parents to their offspring
mutation
-change to DNA that can cause disease
natural selection (evolving type shi)
-process by which species change over time in response to environmental changes and competition for resources
-the organisms with the characteristics that are most suited to the environment survive and reproduce, passing on their genes
population
-group of organisms of the same kind living in the same place
recessive
-a recessive allele will only be expressed if two copies are present.
Punnet square
-a diagram used to show the possible combinations of alleles inherited from the parents.
variation
-any difference between the individuals in a species or groups of organisms of any species
-caused either by:
genetic factors (genotypic variation)
or
environmental factors (phenotypic variation).
genetic variation (discontinuous)
-genes inherited from our parents that do not change and we cannot change
for example:
-sex
-natural eye colour
-blood group
-ability to roll tongue or not
-attached earlobes or not
environmental variation (continuous)
-differences that are caused by the environment around us that we cannot inherit and can change
for example:
-tanned skin
-tattoos
-dyed hair
-scars
factors that affect environmental variation:
-climate we live in
-culture and lifestyle
-diet
-physical injury
intraspecific variation
-the differences between individuals within a species
for example:
-the variety of characteristics within your classmates or family
