(P1) Topic 4: Natural Selection And Genetic Modification Flashcards
What is evolution
The slow, continual change of organisms over a very long time
Who discovered evolution by natural selection
Charles Darwin
Did humans evolve from apes
No, buy we evolved from a common ancestor
What is Lamarckism
The theory that animals could change themselves (evolution by acquired characteristics)
E.g your mothers tattoo would be passed down to you- the theory is wrong
What is one of the effects of evolution
The species will become better adapted to their environment
What could happen is a species does not evolve
They any become extinct
What are the factors that could cause a species that has not evolved to become extinct
Increased population, changes in environment, new diseases, new predators
What were Darwin’s key observations
All living things produce more offspring than the amount that survive to adulthood but in spite of this, population sizes remain roughly constant
Variation exists among species
Characteristics can be passed on from one generation to the next
What is intelligent design
The idea that we can detect intelligence in life
Where does the idea of intelligent design come from
The thought that creatures are perfectly created
What is irreducible complexity
Some organisms are “too complex” to have evolved
What do fossils provide us evidence for
Evolution
What are the earliest human ancestors called
Hominids
How many years ago did Hominids evolve from ape-like animals
4 million
Which human species is closest to Homo Sapiens
Homo Neanderthal
What human species evolved to Homo Neanderthals and Homo Sapiens
Homo Erectus
-migrated out of Africa 1.5 million years ago
-evolved into Neanderthals in Europe
-evolved into Homo Sapiens in Africa
What are the orders of Hierarchical Classification
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is the acrostic for remember hierarchical classification
Definitely Keep Privates Clean Or Face Getting Syphilis
What are the 5 kingdoms + descriptions
Animals- no cell wall, no photosynthesis (eats instead), nucleus
plants- cellulose cell wall, photosynthesis, vacuole, nucleus
fungi- cell wall made out of chitin, no photosynthesis, nucleus
bacteria- single cell, no nucleus
protists- doesn’t fit into any other category e.g seaweed
What is phylogeny
Putting things not groups in increasing specification
What are the 3 domains
Archae, eukaryotes, prokaryotes
What is taxonomy
The study of biological classification
Who is Carl Linnaeus
He set out to prove God created everything by naming everything
What is the basic unit of biological classification
Species
What are the two ways in which a species can be defined
1- what features, both psychological and biochemical, does that animal or plant uniquely posses
2- whether or not the animals within it are capable of of reproducing to produce fertile offspring
What does heredity mean
The passing of DNA to offspring
What is selective breeding
The selection of organisms with desirable (T humans) features to produce varieties of plants and animals that ave desirable features
What takes more time: selective breeding or natural selection
Natural selection
What is artificial selection
The gradual improvement of animal or plant characteristics over time, for man’s benefit
What is a gene pool
All the alleles and genes within a breeding population
what are the issues with selective breeding
Reduces variation (number of alleles)
Smaller gene pool
Can lead to features linked to health problems
What is the issue with having a smaller gene pool
A smaller gene pool may not contain an organism that has an allele to defend against a new disease. This could cause extinction
What is genetic engineering
The alteration of an organisms genome to produce an organism with desired characteristics
What is a positive or CRISPR
It made prices and time of genetic engineering decrease
What is an example of a protein that has been produced in larger volumes thanks to genetic engineering
Insulin
The method is also more acceptable to more people
What is a plasmid
A circular loop of DNA found in some bacterial cells
What can plasmids be used for
Carrying DNA from one cell to another
What is a vector in biology
An agent that carries DNA from one cell to another
What is an example of a vector in biology
A plasmid
What are the steps of CRISPR
- Restriction enzymes cut the DNA backbone at specific sites
- The restriction enzymes make staggered cuts on the DNA backbone that leave exposed bases called sticky ends
- Ligament enzyme acts as a glue between that DNA strands. They join adjacent nucleotides in the backbone
What are the steps for genetically engineering insulin (5)
- The gene that codes for the insulin proven is cut from the DNA using a restriction enzyme
- A plasmid is removed from a bacterial cell
- The plasmid is going to be cut with the same restriction enzyme that was used to cut the human DNA. This results the sticky ends being complimentary
- The complimentary sticky ends of the human DNA and the plasmid are joined together using the enzyme ligase. This forms a recombinant plasmid (human + bacteria)
- Inject the recombinant back into the bacteria
What are the health problems associated with ingesting pesticides
Adverse mental development at 2 years of age,attention problems at 3.5 and 5 years of age, poorer intellectual development at 7 years, Parkinson’s, diabetes, cancer
What is the timescale to develop new pesticides
12 years
What is the cost to develop a new pesticide
£200 million
Why could it be so expensive ad take so long to create a new pesticide
Tricky to create something that only harms what it is meant to-not harmful to the plant (taste, growth, or nutritional value) and also not harmful to humans
What are some suggested benefits of organic produce
Low pesticide levels
Potential risks to human health are largely avoided
Organic milk has higher levels of omega-3 fatty acids
Healthier dietary preferences
Environmental sustainability
Why might farmers use pesticides
It is the cheapest way to kill a great amount of pest- increases revenue the most
Why might some farmers prefer to use alternatives to pesticides
Less health risks to humans
Why do farmers use fertilisers
To replace the minerals (e.g nitrogen, potassium, and phosphorus) in the soil that have already been used by crops in previous years
