Animal Genetics Flashcards
(20 cards)
What causes Variation?
Genetic Variation is caused by organisms having different alleles (genes) which lead to different phenotypes
How does Variation occur?
-via new alleles arising through mutation
-sexual reproduction cause genetic variation in offspring
What is environmental variation?
Acquired characteristics/ characteristics an offspring develops during its life type depending on its surroundings
Give examples of factors that cause environmental variation?
-light
-temperature
-nutrients/ food
-water supply
-defence against predator
What was Darwin’s theory of evolution?
-Random mutations result in variation in species
-Causing mutated organisms to be be better adapted to environment
-Both mutated and non mutated compete (survival rate of the fitness)
-Those better adapted for the environment survive and reproduce
-Overtime these desirable characteristics are more pronounced
What is Lamarck’s theory of evolution?
-Mutations/adaptations are a result of environmental factors effecting characteristics inherited by offspring
How is Antibiotic- resistant bacteria used for Darwinian evolution evidence?
If not all bacteria is killed, the most resistant will reproduce. This is why you must complete a full course of antibiotics
Explain Anti biotic resistance evolution
1- due to mutation bacterium’s with antibiotic resistance allele are produced amongst bacterium without antibiotic resistance
2. Non-antibiotic resistance alleles die due to antibiotics and resistant bacteria is likely to survive
3. Resistant bacteria reproduce and pass on antibiotic resistant allele
4. Resistant allele becomes more common in population
What is meant by species?
Organisms are considered to be of the same species if they can produce fertile offspring
What is selective breeding?
When humans artificially select the plants or animals that have certain desired characteristics to breed in order to produce offspring in which the desired phenotypes (traits) are more pronounced
What is selective breeding used for?
-to make animals produce more meat or milk (farming)
-to develop crops with disease resistance (farming)
-to breed dogs into having good, gentle temperament
-to cause plants to produce bigger fruits (farming)
What happens when you use selective breeding over several generations?
-the desirable characteristics become stronger with each new generation
What are the advantages and of selective breeding?
-important for agriculture
-increases production of crops and livestock for food
-helpful for medical research
-disease and pest resistance can lead to improved livestock and less crop losses
-improves quality’s like taste, size and colour in crops and livestock
What are the disadvantages of selective breeding?
-Loss of genetic diversity/ variation within a population leading them to become more susceptible to disease or environmental change
-Inbreeding which increases risk of inherited diseases and defects
-Potential for health problems due to unintended negative traits (e.g: breathing problems in Boxers)
What is genetic engineering?
The insertion of a gene into an organisms genome (DNA) so it synthesises a specific protein to achieve a desired characteristic
Give examples of genetic engineering?
-Insulin producing bacteria (that can be harvested to help those with diabetes
-creating genetically modified crops like golden rice which produces Vitamin A (boots nutrients and vitamins in plants)
-Disease- creates resistant plants/crops for agriculture
Explain the 4 steps for genetic engineering?
- Desired gene is cut from another organisms DNA using restriction enzyme leaving it with sticky ends
- Gene is inserted into a vector(e.g: bacteria, plasmid or virus using ligase enzyme
- Vector inserts gene into cells of another organism early in development (just before egg has been fertilised)
- Organism develops with desired characteristic due to every cell synthesising that specific protein
What are the pros of genetic engineering?
-gives crops more desirable characteristics (more fruit, disease-resistant) good for agriculture
-makes sure plants produce special nutrients (golden rice= vitamin A)
-Important for developing countries struggling with starvation
What are the cons of genetic variation?
-we don’t know how genetically modified plants may effect our health
-chance plants may spread into the wild and compete with other plants, changing the ecosystem
Why is it unlikely plants may spread into the wild and compete with other plants, changing the ecosystem?
Unlikely as plants are modified to survive in farmers fields not the wild
