Variation Flashcards
What are alleles?
Different forms of the same gene
What is a mutation?
A change in DNA
Name 3 methods of cloning.
Tissue culture, cutting, embryo transplant
Why is selective breeding useful?
It helps to give a population/species favourable characteristics
Name 2 disadvantages of selective breeding.
- Can lead to inbreeding which can cause inherited defects or diseases
- Reduces variation which can mean all animals of a species could be susceptible to a disease
What is the process of cloning?
- An adult cell is taken from one animal and a mature egg cell from another animal (of the same species)
- The nuclei are removed from both cells
- The nucleus from the adult cell is fused with the now-empty egg cell
- The new cell, now an embryo, is placed inside the uterus of another animal and it gives birth to a clone
Name 3 advantages of cloning.
- Desired characteristics guaranteed
- Quick and economical
- Large number of identical offspring are produced
Name 3 disadvantages of cloning.
- Limits variation, reduction in gene pool
- Clones can be vulnerable to diseases or changes to the environment
- Ethical concerns
What is genetic engineering?
A process that involves changing the genome of an organism (by introducing a gene from another organism) to produce a desired characteristic
Name 3 benefits to genetic engineering.
- Potential to overcome inherited diseases
- Can lead to higher value of crops (GM crops have higher yield)
- Crops can be engineered to be resistant to herbicides and make their own pesticides
Name 3 disadvantages to genetic engineering.
- Genes from GM plants and animals can spread to other wildlife which can devastate the ecosystem
- Ethical concerns
- Some believe the long-term effects of consuming GM crops have not been fully explored
What 2 factors (or a combination of) can cause variation?
- Genetic causes
- Environmental causes
How have bacteria been genetically engineered?
To be produce useful substances (like human insulin to treat diabetes)
How have plant crops been genetically engineered?
- To be resistant to diseases, herbicides and pesticides
- To produce bigger fruits
- To produce higher yields
In genetic engineering, what is used to transfer the required gene into the new cell?
A vector (e.g: bacterial plasmid or virus)
What is tissue culture cloning?
Using small groups of cells from plants to grow identical new ones
Why is tissue culture cloning important?
- Preserving rare plant species
- Growing plants commercially in nurseries
What is embryo transplant cloning?
When cells are split apart from a developing animal embryo to become specialised, then reinserted into a host mother.
