When individuals with the extreme allele expressions are favored in an environment, what type of natural selection is this? Explain.
Directional or disruptive selection.
Explain Gametic Isolation.
The egg and sperm never meet, as the sperm may not be viable in the reproductive tract or possess the traits required for fertilization.
All species, living or not, were derived from a common ancestor linked by a single tree of life is known as whar?
Descent with modification/common descent. Concept where all species are thought to have been derived from one ancestor/origin
What is Darwin's theory of evolution. Explain two points.
Variations exist in a pop., Cannot obtain adaptation, survival of the fittest, favorable traits survive + reproduce, time for change, descent with modification
What is the similarities between allopatric and sympatric speciation. What is the difference?
Both involve the creation of new species. Allopatric - geological barriers, Sympatric - issues with cell division or mutations.
What is the difference between acquired traits and traits that can be passed on?
acquired traits are acquired characteristics, not coded in our DNA. Traits that are passed on are coded in our DNA and therefore can be passed on to offspring.
Explain homozygous and heterozygous.
Homozygous - genotype with 2 same alleles. Heterozygous - genotype with 2 different alleles.
Humans breed cats to produce only orange cats, this is an example of?
Artificial selection
Two species of grass plants flower at different times of the year, but they live in the same habitat. Which isolation mechanism is this?
Temporal isolation - pre-zygotic
How is convergent evolution different from coevolution?
Convergent evolution is when two different species in same environment develop similar traits, coevolution is when two different species impact eachother evolut
Explain the founder effect and bottleneck effect.
Founder - population migrate to new isolated area. Bottleneck - rapid decrease in pop due to disaster/human activity. Both cause change in allele frequency
How do we distinguish species from one another? What is the criteria?
Physiology, Biochemistry, Behaviour and Genetics
Over time, scientists have noticed that babies that are born at an intermediate weight are more likely to survive than babies born either much smaller or much larger than average. This phenomena can be shown in a graph depicting
Stabilizing selection as the intermediate is being favored.
The crossing of two species produces a fertile hybrid offspring. This hybrid goes on to produce an offspring that is weak and infertile. This is which isolation mechanism?
Hybrid breakdown - post-zygotic.
Explain micro and macroevolution.
Micro - a small change, in one pop. Macro - a bigger scale change that leads to the creation of new species.
What is gene flow?
change in allele frequency due to movement between populations
What was Jean-Baptise Lamark's theory? Explain it.
We can acquire any trait that we want depending on our environment and this trait can then be further passed on to our offspring.
Explain Post-zygotic Isolating Mechanism, what does it mean?
The hurdles after egg and sperm meet.
There is a population of beetles found in a specific deciduous forest. A few of these beetles end up in a different deciduous forest and are able to reproduce. This causes the frequencies of alleles to change. What effect is this?
Genetic Drift - Founder Effect
What is the difference between a genotype and phenotype?
Genotype - genetic code through alleles that code for trait. Phenotype - describing a trait we can sometimes see physically.