week 1
What are the three different categories of domains
Eukarya, Bacteria, Archaea
a population has an allele frequency of
F(AA)=90% F(Aa)=7.5% F(aa)= 2.5%
what does this say about the heterozygosity of the population?
The population has a low heterozygosity, because most of the population has only A alleles, not very much genetic diversity.
a clade shows the following characteristics
https://docs.google.com/document/d/1Geg1XUTg_c3nHVwK9loMXnJ0ko1JHKYvul6QmFKzGoU/edit?tab=t.0
which of the following is the outgroup, and why?
Bonus points if you can construct a phylogenetic tree of this clade!
D is most likely to be the outgroup because it doesnt share any of the derived characters of the other clade members. it would be the group that is the most similar to the last common ancestor
what are "seaweeds"?
they are algae/ sea organisms with plantlike features
what seedless plant is a renewable source of energy
sphagnum moss (peat)
what does it mean if a species is Endemic?
they are not found anywhere else in the world
What are the three modes of selection, provide an example for each
Directional selection favours individuals at one end of the phenotypic range (ex. predators eating mostly white mice because they are easier to see)
–Disruptive selection favours individuals at both extremes of the phenotypic range (predators eat brown mice because they are more abundant)
Stabilizing selection favours intermediate variants and acts against extreme phenotypes( predators eat black and white mice only)
What is horizontal gene transfer?
movement of genes from one genome to another by exchange of transposable elements and plasmids, viral infection, and fusion of organisms
what are the four eukaryotic supergroups
excavata, SAR clade, Archaeplastida, Unikonta
what does phloem do?
distributes sugars, amino acids, and other organic products from leaves of plant.
what are the requirements for a population to evolve
the population must have variance, inheritability of traits, and must have individuals with characteristics that give them a natural advantage.
What is microevolution? give one example of what can help contribute to it
Micro evolution is a change in allele frequencies in a population over generations.
it can be effected by Natural selection, Genetic drift, and gene flow
Three ways Prokaryotic DNA can be brought together
Transformation, transduction, conjugation.
what is symbiosis, and what are the three main types?
when 2 species live in close contact and form relationship
mutualism
commensalism
parasitism
what is being described?
-transports water and minerals, one way flow, form center of vascular bundles
xylem
What is the difference between homologous and analogous structures?
bonus points if you can give TWO examples of both
Homology is similarity from common ancestry
ex, birds and bats, whales and fish fins
Analogy is similarity that is NOT from common ancestry, it arises when groups adapt to environments in similar ways
ex. flying squirrels and sugar gliders, bats and butterflies
What is the bottleneck effect? what effect can it have on genepool of a population?
a sudden reduction in population size due to a change in the environment. bottleneck events leave a RANDOM assortment of survivours.
ex natural disasters.
the surviving members of the population may not have the same allele frequency of the original population
what are the differences between gram- and gram + bacteria?
gram -
thin layer of peptidoglycan, and an outer membrane, more likely to be antibiotic resistant
gram+
thick peptidoglycan layer
what are the two types of slime moulds, and what supergroup are they in?
Plasmodial and cellular slime moulds. unikonta
what type of plants eventually became coal?
Decaying plants of Carboniferous forests
why is the fossil record so important?
shows the extinction of species
origins of new groups (offshoots from common ancestors)
changes in groups over time
what is the difference between allopatric and sympatric speciation?
allopatric is genetic divergence due to a population being isolated and dividing into sub-populations
sympatric speciation is genetic divergence in a population in the same location (normally caused by factors such as sexual selection, polyploidy, etc)
Describe maximum parsimony. how would a parsimonious tree differ from a likely tree
Maximum parsimony hypothesizes that events occurred in the simplest, most obvious way, and the pathway of evolution probably includes the fewest major events that coincide with the evidence at hand.
parsimony is nice but more often in biology, things take more major events so a likely tree would show more evolutionary events
what is endosymbiosis, and what common organelles arose from this
process in which a unicellular organism engulfs another cell, which becomes an endosymbiont and then an organelle in the host cell.
chloroplasts and mitochondrion
what is the difference between microphylls and megaphylls?
Microphylls are leaves with a single vein.
Megaphylls are leaves with a highly branched vascular system.