B6 complete Flashcards
(21 cards)
What does natural selection increase?
Advantageous phenotypes
What is natural selection often referred to as?
‘Survival of the fittest’
What is the definition for natural selection?
Hint: “Think survival of the fittest”
The process whereby organisms adapted better to their environment tend to survive and produce more offspring
Who came up with the theory which helps explain Evolution?
Now we know natural selection leads to…
Charles Darwin
The evolution of species
Observations of fossils can provide evidence for evolution
What are fossils? And where are they most commonly found?
A fossil is any trace of an animal or plant that lived long ago.
Most commonly found in rocks
What is selective breeding?
Selective breeding is mating with the best organisms to get good offspring.
What is a problem with selective breeding?
Selective breeding causes a reduction in the gene pool - the number of different genetic variants in a population.
This happens because the farmer keeps breeding the “best” animals or plants which are all closely related. Known as inbreeding
Ideas about evolution influenced modern biology
Name 3 areas it has affected and go into some detail
Hint: c… a… c…
Classification - classified by how closely related they are because we know now that we are all related in some way.
Antibiotic resistance - Now we understand the importance on finishing our prescriptions to prevent resistant bacteria spreading and we now know we need to keep developing new drugs to fight newly evolved resistant bacteria.
Conservation - We now understand the importance of genetic variation and how it helps populations adapt to changing environments. Led to conservation projects to protect species.
One advantage and disadvantage for asexual reproduction.
`Advantages:
- -> Produces lots of offspring very quickly because reproductive cycle is so fast.
- -> Only one parent is needed - this means organisms can reproduce whenever conditions are favourable not having to wait for a mate.
Disadvantages:
- -> No genetic variation. Individuals, genetically identical.
- -> So if environment changes, conditions become unfavourable the whole population is affected.
One advantage and disadvantage for sexual reproduction.
Advantages:
- -> Genetic variation. Individuals with different characteristics
- -> This will lead to evolution because species become better adapted to their environment
Disadvantages:
- -> Process takes more time and energy than asexual reproduction. Produce fewer offspring in lifetime
- -> Two parents are needed, problematic if individuals are isolated.
What is classification?
Organising living organisms in to groups
Process of evolution produces many new species…
6 mark, 6 bullet points
Hint: 1=Mutation occurs
~A random mutation occurs
~Changes a characteristic in the species
~Competition for food+mates
~Natural selection-‘survival of the fittest’
~Mating happens
~Sexual reproduction occurs because you are passing on the mutation to your offspring.
How do we show how species are related to each other?
Evolutionary trees
What is biodiversity?
Biodiversity is all about the variety of life in an area
Biodiversity is a combination of three different factors.
Hint: …..in a particular area
The diversity of living organisms in a particular area
The diversity of genes and alleles in a particular area
The diversity of different ecosystems in a particular area
Human interactions can reduce biodiversity; state the three factors. And why they destroy ecosystems
An increasing in human population Industrialisation Globalisation Due to: Habitat destruction Waste Sharing resources
What is sustainability?
Sustainability means meeting the needs of today’s population without harming the environment or using resource, so that future generations can still meet their own needs.
What do environmental changes affect? And what are the environmental changes?
Environmental changes affect the distribution of organisms
And the changes are availability of water and atmospheric gases.
What are the 2 factors that make maintaining biodiversity challenging?
Economic issues
Moral issues
Ecological issues
Political issues
3 factors affecting food security…
Environmental change Changing diets in wealthier populations New pests and pathogens Sustainability Cost of agricultural inputs
2 methods for improving food security
Improved nutrition Chemical control of pests Protection against pathogens Hormones Selective breeding
