B14-Variation Flashcards
Genes determine the phenotype of an organism-true or false
False-the environment also plays a role
What is variation within a population?
Differences in the characteristics of individuals in a population
State 3 causes of variation in a population
Genes, environment, a combination of both
What causes variation within a population?
Mutations
What is evolution?
A change in the inherited characteristics of a population over time through a process of natural selection which may result in the formation of a new species
What does the theory of evolution by natural selection state?
That all living things evolved from simple life forms more than 3 billion years ago
What would the best organism within a species to survive and reproduce be?
The one best adapted to the environment
Define species
Organisms that can interbreed to produce fertile offspring
Define natural selection
The process by which evolution takes place-nature chooses those with favourable characteristics(best suited to environment) to survive and reproduce passing on their genes
What is selective breeding?
The process by which humans breed plants and animals for particular genetic characteristics
Name 2 historic examples of selective breeding
1-breeding food crops from wild plants
2-domesticating animals
State 4 modern examples of selective breeding
1-disease resistance in food crops
2-animsl which produce more meat or milk
3-domestic dogs with a gentle nature
4-large or unusual flowers
State a drawback to selective breeding
Inbreeding-some breeds are prone to disease or inherited defects
What is genetic engineering?
The process which involves modifying the genome of an organism by introducing a gene from another organism to give a desired characteristic
State 3 traits plant might be genetically engineered to have
Resistant to insect attack, resistant to herbicides, increased yields
Give one example of the use of genetically engineered bacterial cells
To produce useful substances such as human insulin to treat diabetes
How is a gene ‘cut out’ from the genome of one species and inserted into the genome of another?
Using enzymes
Into what is the gene inserted?
A vector
Give 2 examples of vectors used in genetic engineering
A bacterial plasmid, a virus
What is plant tissue culture?
Using small groups of cells from part of a plant to grow identical new plants
What are plant cuttings?
An older, but simple, method used by gardeners to produce many identical new plants from a parents plant
Where might plant cloning be useful?
Horticulture and agriculture
Describe the 2 steps involved in embryo transplanting
Splitting apart cells from a developing animal embryo before they become specialised transplanting the identical embryos into host mothers
Compare the offspring from embryo transplants with each other and with the parents
Genetically identical to each other; different from parents
State a disadvantage to cloning plants and animals
Reduces genetic variation, so makes populations more susceptible to disease
In adult cell cloning, what is removed from the cloning target’s cell in order to create its clone?
Nucleus
What type of cell is taken from the target clone in adult cell cloning?
Any body cell(except gametes)
What has to be done to the egg cell in adult cell cloning?
Remove its nucleus
What is needed to stimulate the new egg cell to divide in adult cell cloning?
Electric shock
Compare the offspring in adult cell cloning to both its parents
Genetically identical to nucleus donor; different from the egg cell donor
State 2 benefits of genetic engineering
Improved growth rates, increased yield, increased food quality, produce human proteins, enzymes as medicine
State 3 concerns around genetically engineering plants
1-unknown effects on populations of wild flowers
2-unknown effects on populations of insects
3-some people feel the effects of eating GM crops on human health have not been fully explored
