Yr 8 Variation Test Flashcards
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
interspecific variation
-the differences between species in an ecosystem
for example:
- the variety of characteristics between lions and cheetahs in Africa.
biodiversity and variation difference
b-measure of all the differences
v-sum of all the differences
selective breeding
-2 adavantageous characteristics of animals/plants that are bred together
mitosis
-a process where a single cell divides to produce two identical daughter cellsused for growth, repair, and asexual reproduction.
stages:
1. 46 chromosomes in the cell
2. The chromosomes double
3. Chromosomes line up in the middle
4. Chromosomes pulled apart
5. Cytoplasm and nuclear membrane start to divide
6. Two identical daughter cells are formed
