Biol Lab Exam Quiz 1 Flashcards
Population
All organisms of the same group or species that inhabit the same area and can interbreed
What are the assumption of HWE?
No Selection
No Gene flow
Random mating
Infinite population size
No mutation
HW Equation
p^2 + 2pq + q^2
allelic frequency
how often an allele shows up in a population
Genotypic frequency
how common a single phenotype occurs in a population
Describe how you would expect the allelic and genotypic frequencies of a population to change when subjected to each of the five evolutionary processes (Genetic drift)
frequencies will change randomly - if the population is small enough, it may lead to the fixation of one of the alleles.
We discussed two methods for deleterious alleles to persist in a population. What were these? Which applied to Sickle Cell Anemia ?
-Heterozygote Advantage (This applied to SCA!)
-Recessive Refuge
Heterozygote advantage
when the heterozygous genotype has an advantage over either of the homozygous genotypes
examples: being heterozygous with an allele for sickle cell trait and an allele for normal red blood cells.
gel electrophoresis lane 1
positive control
In terms of the malaria experiment: HbS-HbS genotypic blood (sickle cell)
gel electrophoresis lane 2
negative control
in terms of the malaria experiment: HbA-HbA genotypic blood (no sickle cell) (will be further down compared to the sickle cell control)
What does it mean if the hemoglobin travels farther?
Normal hemoglobin travels faster than those with sickle cell anemia because of its shape. So further travel means normal hemoglobin.
Recessive Refuge
phenomenon that enables a deleterious recessive allele to persist in a gene pool by “hiding out” in heterozygous individuals
Apomorphy
new, derived characteristic unique to a group or species. (not present in ancestor)
plesiomorphy
ancestral trait a taxon retains throughout its evolution.
synapomorphic traits
shared derived traits present in entire clade
autapomorphic traits
unique, derived traits found in only one group and absent in even the closest ones
symplesiomorphic traits
shared, ancestral trait (shared by two taxa and still have the ancestral trait)
sister taxa
two taxa that share the most recent common ancestor
Node
branch point that represents a taxonomic level
Convergent evolution
when two organisms separately developed similar traits due to being in similar environments
Monophyletic
single common ancestor and ALL its descendants
Paraphyletic
common ancestor + some descendants
Polyphyletic
grouping with no recent common ancestor
Importance of an outgroup and how its represented on a character matrix
has all the ancestral (plesiomorphic traits)
- used to compare to other organisms
- numbered with all 0s always
Synapomorphy verses analogous trait
synapomorphic comes from related species while analogous trait is similar traits in organisms that arise for reasons other than relatedness.
principle of parsimony
cladogram with the fewest changes is usually the best
domain eukarya
- DNA is linear
- have nuclei
- have membrane-bound organelles (chloroplast / mitochondria)
- mitosis and meiosis
domain bacteria
- DNA is circular
- no nucleus
- no membrane-bound organelles
*defining characteristic of a cell wall made of peptidoglycan
Archaea
- no membrane bound organelles
- no peptidoglycan
*3. branched membrane lipids - circular chromosomes
Shapes of bacteria
Coccus: round bacteria
Bacillus: rod like bacteria
Spirilla: spiral bacteria
Why is it sometimes difficult to determine the phylogeny of single celled organisms
Because they may contain genes from other prokaryotes nearby or simply have no shared genes from the common ancestor.
Aerobic Bacteria
Require oxygen
Anaerobic Bacteria
Cannot tolerate oxygen
Facultative Anaerobes
Prefer oxygen, but can survive without it
Why are cyanobacteria ecologically important
responsible for the oxygenation of the ocean and air some fix nitrogen from the air via heterocyst cells (fundamental food and nutrients for plants that can’t consume nitrogen in the air)
What distinguishes cyanobacteria from other bacteria?
Contain thylakoids and perform oxygenic photosynthesis.
theory of endosymbiosis
mitochondria and chloroplasts may have originally been bacteria that were engulfed and embraced by a larger bacteria or eukaryote
Akinete
allows cyanobacteria to live in harsh environments and preform nitrogen fixation
heterocyst
lets cyanobacteria photosynthesized
Excavata groups
Eukarya
Excavata
Eugenozoa
Subgroup: euglendia
ex: Euglena
Excavata Characteristics
1-2 flagella
Flexible penecile
stigma protien (eyespot)
look like a squigly leaf sorta
What trophic are Euglena
Mixotrophic
Unikonta
Eukarya
Amoebozoa
ex: slime mold, amoeba, Pelomyxa
Characteristics of Amoebozoa
No shell or cell wall
large single celled organism
Tubular pseudopodia
Archaeplastidia
Archaeplastidia
1. Chlorophyta
->Chlamydomonas / volvox
2. Charophyta
3. Spirogyra
Which organism is completely unicellular (does not form colonies)
Chlamydomonas
Which organisms are colonial?
Volvox
By what methods do Chlamydomonas reproduce?
Isogamous reproduction (they are their own gametes)
How do Chlamydomonas reproduce in harsh conditions?
produce resistant diploid zygotes and will do meiosis when conditions are more favorable.
