Natural Selection And Genetic Modification : Test 4 Flashcards
What is Darwin’s theory of evolution by natural selection
Individuals with characteristics most suited to their environment were more likely to survive, reproduce and therefore pass on their characteristics to their offspring.
What is speciation
A process that results in the formation of a new species
Why can speciation occur
As a result of a combination of isolation and natural selection
Define evolution
The change in frequency of a phenotype in a population over many generations
What sequence do all examples of natural selection follow
-Within a species there is always a variation and chance mutation
- Repeated over generations, the mutated phenotype will become the norm
- Some individuals will develop a phenotype (characteristic) that gives them a survival advantage and this allows them to : live longer,breed more, be more likely to pass their genes on
Describe antibiotics
Antibiotics are chemical substances made by certain fungi or bacteria that affect the working of bacterial cells, either by disrupting their structure or function or by preventing them from reproducing. Antibiotics are effective against bacteria but not against viruses. Antibiotics target processes and structures that are specific to bacteria (prokaryotic) cells as they do not generally harm animal cells.
Describe how antibiotic resistance happens
An antibiotic is used in the body to kill the bad bacteria and some of the good bacteria dies. There are some resistant bacteria that survive and they multiply. When the antibiotics are taken again it won’t work as all the bacteria would be resistant.
What are humans and their ancestors known as?
Hominids
What is a pentadactyl Limb ?
Any limb that has 5 digits
What are some examples of animals with a pentadactyl limb like humans ?
Cats, Whales, Chickens, Dolphins, Bats
What are the 5 kingdoms ?
Animals- fish, mammals, reptiles etc
Plants- grasses,trees etc
Fungi- mushrooms, toadstools, yeast and mould
Prokaryotes- all single- celled organisms without a nucleus
Protists- eukaryotic single celled organisms e.g. algae
What are the smaller groups that the kingdoms subdivided into ?
Phylum, class, order, family, genus, species
What was the three domain system by Carl Woese and why was it done?
It was created because it was realised that members of the prokaryote kingdom were not as closely related as it was first thought. Woese decided that all organisms should be divided in three large groups called domains. They include archaea, bacteria and eukarya
What is the archaea domain ?
Organisms in this domain look similar to bacteria but are actually quite different as differences in their DNA and RNA sequences show they were first found in extreme places such as hot springs and salt lakes
What is the bacteria domain ?
This domain contains true bacteria like E. coli and Staphylococcus
