Block A: Origins of Life, the Kingdoms and Evolution Flashcards
What is the Second Law of Thermodynamics?
All things must lead to an increase in disorder (increase in entropy)
(Lecture 1, Slide 7)
What formed first; DNA or RNA?
RNA
(Lecture 1, Slide 22)
What are the key features of the origin of life?
Changes and progression occurring over time and complexity and diversity increasing over time.
(Lecture 2, Slide 11)
What accumulates in every organism’s DNA over time?
(Random) Mutations
(Lecture 2, Slide 28)
What do random mutations create?
A “gene pool” full of heritable information
(Lecture 2, Slide 28)
Population growth in kept in check by the “struggle for existence”; how is this achieved?
Selection Pressures
(Lecture 2, Slide 29)
What are 5 examples of selection pressures?
Animals competing for resources and mates, predation from other animals, disease, and changes in the environment.
(Lecture 2, Slide 29)
What makes some individuals better at coping with selection pressures than others?
Genetic differences between individuals
(Lecture 2, Slide 30)
What do genetic differences lead to?
Leads to organisms to survive / thrive better to produce more offspring
(Lecture 2, Slide 30)
What are the 3 different types of natural selection?
Stabilising, Disruptive and Directional
(Lecture 2, Slide 35)
How does carbon dating / potassium-argon dating work?
Age of fossil depends on time-course of radioactive decay of carbon 14 / decay of potassium to argon.
(Lecture 3, Slide 4)
How does the fossil record help confirm the theory of evolution?
Fossils are dated using carbon dating and potassium-argon dating, and earlier fossils are found in deeper layers, therefore clearly showing how organisms have changed over time.
(Lecture 3, Slide 4)
What is the punctuated equilibrium model of evolution?
Suggests a period of evolutionary status where no change
occurs accompanied by intervals of rapid change.
(Lecture 3, Slide 7)
What is the gradualist theory of evolution?
Suggests that change occurs little by little and that the record is incomplete.
(Lecture 3, Slide 7)
What part of a fossil is best preserved?
Hard tissue such as bones and shells.
(Lecture 3, Slide 4)
How does DNA, vital physiological processes and ATP support the theory of evolution?
DNA is universal, ATP is used as a common energy currency, and vital physiological processes such as respiration are biochemically very similar.
All these points signify relatedness between species.
(Lecture 3, Slide 10)
What are 3 ways genes support the theory of evolution?
Functional molecules - can be shuffled together forming new genes
Gene families - groups of homologous molecules having similar functions
Genome duplication - allowing new genes to form without affecting the original.
(Lecture 3, Slide 10)
Explain how comparative anatomy supports the theory of evolution.
Anatomy is similar between animals in related species with convergent analogous functions i.e. species developing similar features as a result of dealing with similar selection pressures - suggesting a common ancestor.
(Lecture 3, Slide 16)
What is the definition of a species?
“a group of organisms with similar features which can interbreed to produce fertile offspring and which are reproductively isolated from further species”
(Lecture 3, Slide 22)
How does allopatric isolation lead to speciation?
Individuals from a species are geographically isolated, where conditions may be different for both sets of individuals, where natural selection will eventually create 2 different species.
(Lecture 3, Slide 23)
How does Sympatric isolation lead to speciation?
Members from a species are unable to breed with each other due to certain isolation mechanics. As these sets of members eventually create 2 different gene pools, they will eventually become 2 different species.
(Lecture 3, Slide 23)
What is microevolution?
Microevolution is the evolution we can see today; stabilisation of advantageous mutations and a change of allele frequency in response to environmental pressures.
(Lecture 3, Slide 31)
What is artificial selection and how does it help support the theory of evolution?
Artificial selection is when humans act as the selection pressure and it supports the theory of evolution as we can see organisms change in response to us.
(Lecture 3, Slide 38)
How does cancer occur?
Mutation either triggers uncontrolled cell division, or removes protection against it.
(Lecture 3, Slide 45)