B15 Flashcards
What did Mendel’s discoveries prove?
Mendel used different types of pea plants, cross bred them and counted the different offspring. He found characteristics were inherited in clear and predictable patterns. He explained his results by suggesting there were separate units of inherited material and realised some were dominant.
What happened to Mendel’s theories once DNA was discovered?
Once James Watson and Francis Crick were trying to build a model of DNA they figured it out and therefore ties in with the characteristics of the DNA.
Why was Darwin’s theory of evolution only accepted gradually?
This was due to the theory of evolution by natural selection challenged the religious beliefs, insufficient evidence and no mechanism for explaining variation and inheritance as genetics were not understood.
What did Darwin’s theories surround?
It was around evolution by natural selection and how conditions in an environment can let only the fittest survive and reproduce, causing evolution as only the best adapted survive.
What did Alfred Russel Wallace discover?
He independently proposed the theory of evolution by natural selection and published join writings with Darwin. He is best known for his work on the theory of speciation.
What is speciation?
This is where parts of a population become isolated due to a new environmental condition. Then the genes for the good characteristics are passed on through reproduction and once an animal changes so much that it cannot produce fertile offspring with the original organisms, a new species has formed.
What are fossils?
They are the remains of organisms from millions of years ago.
How can fossils be formed?
When an animal or a plant does not decay after death, where harder parts of the animal is replaced by rocks and minerals as they decay and as some of the fossils are not actual left animals or plants but footprints and traces from millions of years ago.
What is extinction?
It is the permanent loss of all members of a species.
How can an organism become extinct?
By new predators, environmental changes, new diseases, new competitors, hunters and urbanisation.
How can you prevent more resistant strains of bacteria from appearing?
Through not overusing antibiotics and not using them on minor things and viruses. Through making sure the patient finishes course of medicine if they’re on antibiotics and restricting agricultural use of antibiotics.
What is MRSA?
It is a bacteria that is resistant to antibiotics, carried in hospitals.
What is classification?
The organisation of living things into groups according to their similarities.
What is the order for classification and how can you remember it?
King-kingdom
Prawn-phylum
Curry-class
Or-order
Fat-Family
Greasy-Genus
Sausages-Species
What is a domain?
There is a three domain system and it consists of archaea(primitive forms of bacteria), bacteria and eukaryote(organisms that carry a nucleus).
What did Lamark believe?
He thought that the animals became adapted within their lifetimes, as giraffes needed to get high fruits so grew long necks and then passed on that trait but he was wrong.
