Topic 4 - Natural Selection And Genetic Modification Flashcards
How does Natural Selection work?
Mutations cause variation in a population. Factors such as predation, competition and disease affect an organism’s chance of surviving to an age where it can reproduce and pass on the mutated gene. Organisms that have mutated useful genes are more likely to reach that age, and so are their offspring that get the gene. Organisms without the gene die off. Leaving the organisms with the gene.
How do bacteria provide evidence for evolution?
Bacteria can mutate. Sometimes this mutation can make bacteria resistant to an antibiotic. When the bacteria come in contact with the antibiotic, the non-resistant bacteria die. Making it easier for the resistant bacteria to survive.
Ardi is a fossil hominid from 4.4 million years ago found in Ethiopia. What where its main features?
The structure of her feet suggests she climbed trees. She had an ape-like big toe to grasp branches.
Long arms and short legs
Brain size about the same as a chimpanzee’s.
Structure of her legs suggest she walks upright.
Lucy is a fossil hominid from 3.2 million years ago found in Ethiopia. What where its main features?
Arched feet more adapted to walking than climbing.
The size of arms and legs between the size you would expect to find in apes and humans.
Brain larger than Ardi’s but still similar to a chimp’s brain.
The structure of her bones suggest she walked upright with more efficiency than Ardi.
In 1984 Richard Leakey found the 1.6 million year old fossil skeleton, the Turkana boy, in Kenya. What where the main features of it?
Short arms and long legs more like a human than an ape.
Brain size much larger than Lucy’s.
The structure of his legs suggest he walked upright with more efficiency than Lucy.
What are the 3 groups called that are organisms can be put into?
The three domains
Name the three donains
Archaea
Bacteria
Eukarya
What goes in the Archaea domain?
Organisms that look similar to bacteria but are found in extreme places such as hot springs and salt lakes.
What is in Eukarya domain?
Fungi, plants, animals and protists.
How are organisms put into the domains?
RNA sequencing
Advantages of selective breeding
Animals can be bred that produce more meat or milk.
Resistance to a disease can be spread through a population
Disadvantages of selective breeding
Reduces the gene pool
Inbreeding causes health problems
Less variation means less chance or resistance genes being present. So when a new disease appears it could wipe out the population.
What is a vector in genetic engineering?
Something that’s used to transfer DNA into a cell.
How does genetic engineering work?
The DNA you want to insert is cut out using restriction enzymes. The vector DNA is then cut open using the sam enzyme. Ligase enzymes join the pieces of DNA together at the sticky ends to make recombinant DNA. The recombinant DNA is inserted into other cells.
How did Charles Darwin contribute to the theory of evolution?
He noticed variation in members of the same species and that those with the characteristics most suited to the environment were most likely to survive. He also noticed those characteristics could be passed on to offspring.
