Last Exam Bio Flashcards
What does it mean to “express” a gene?
the gene is turned on and proteins are being made
What is allelic exclusion?
when one is dominant and the other isn’t expressed
Give an example or two of why certain genes are expressed over another.
-allelic exclusion
-dominance
What is a karyotype? What are the best phases of the cell cycle to do this?
condensed chromosome, prophase
What chromosome combinations relate to biological sex? How is allelic exclusion applied in sex chromosomes?
X and Y chromosomes, Y chromosome will turn off female genes from X chromosom
What is trisomy?
when there’s three chromosome
What is the difference between recessive and dominant genes? How is this related to allelic exclusion?
dominant is expressed protein, unless two recessive
What was Darwin’s “blending inheritance” theory? Why is it wrong?
dilution until clones, wrong because still so much diversity
What is incomplete dominance
when both alleles are expressed (all skin tones dominant)
What is the meaning of Darwin’s “survival of the fittest”? What is evolution?
overtime certain traits become more common because they’re better for survival
Who are the following, and what did they think about genetic inheritance?
A. Hippocrates
B. Jean Baptiste Lamarck
C. Charles Darwin
D. Gregor Mendel
A. Hippocrates
-traits are an expression of proteins, passed parent to child
B. Jean Baptiste Lamarck
-evolution, traits change over time
C. Charles Darwin
-origin of species, survival of the fittest
D. Gregor Mendel
-study of peas, “GENES” passed down from parents, DNA is different than the traits
Define evolution
when traits change over time
What are the two components of “survival of the fittest” and how does it relate to evolution?
-survive
-reproduce
What’s the difference between genes and traits?
genes- DNA
traits- proteins expressing DNA (not recessive)
Define purebred and hybrid
pure bred
-homozygous
-same allele from both parents
hybrid
-heterozygous
What are the P1 and F1 generations?
P1
-parents
F1
-first generation
What is a genotype? A phenotype? How does an organism’s genotype lead to certain phenotypes, keeping in mind dominant and recessive alleles?
genetype
-DNA
phenotype
-whats expressed
How does genetic dominance work with human blood types (A, B, and Rh antigens)?
A B and Rh are codominant, they can all be expressed together
What is the significance of the “independent assortment” or genes?
creates genetic diversity
how do blood cell proteins work
if blood cell has A B or Rh (+) proteins they will be attacked if not a match
What is epigenetics? Give at least one example of epigenetic expression.
when the environment affects gene expression, skin cells vs heart cells different by need
How do twin studies help us understand epigenetics?
they have the same DNA but can still look different
What is the job of the enzymes Mut S, Mut L, and Mut H?
work together the check if double helix is smooth (bump = mismatched bases)
mut s- finds mismatch
mut l- connects them
mut h- cuts nucleotide so it can be fixed
What is the function of DNA polymerase?
-protein that copies DNA, fixes its own mistake, used for DNA replication
USED IN PCR
Describe how our cells develop mutation. Describe how our cells can correct DNA mutations.
when a base is copied wrong, muts slh
6 types of mutations
silent (synonymous)
-DNA change, dif base same codon
missense (nonsynonymous)
-DNA change, codon/AA change
stop (nonsense)
-stop codon added
frameshift
-adding or removing base, shifts other bases over (new groups of three)
germline
-gametes have mutation
somatic
-cancer, WBC kill messed up cells
What is a restriction enzyme/endonuclease? Can you recognize where a given enzyme will cut given a diagram?
-it cuts DNA a certain way (uneven two strands)
blunt vs sticky end? How are they useful for manipulating DNA?
blunt
-even cut
sticky
-uneven cut
-allows DNA to get inserted into the sequence
whats PCR
polymerase chain reaction
-makes a ton of DNA
- Name the protein that can convert RNA into DNA.
reverse transcriptase
- Why would we want to extract mRNA from a cell and turn it into DNA for PCR?
you dont wanna take DNA out of a cell
- What kinds of nucleic acid can a virus use for its genome?
-both RNA and DNA
- What is a capsid made of?
protein
- Why would an RNA virus use reverse transcriptase?
to make DNA in order to replicate
- What does RT-PCR stand for? Why do we do it?
reverse transcriptase polymerase chain reaction
-to turn RNA -> DNA, and make more DNA
- List the “ingredients” needed to run PCR.
-DNA
-DNA polymerase (taq polymerase)
-nucleotides: AGTC
-buffer: liquid with salt at a pH
-primer: small piece of DNA (forward and reverse primer)
- What does a buffer do in PCR
maintains pH to prevent denaturing of Taq Polymerase
- To what strand does the Forward Primer bind? To what strand does the Reverse Primer bind?
Reverse primer
-binds to positive strand
Forward primer
-binds to negative strand
- Know the steps of the PCR cycle.
denaturation (hottest)
-split strands
annealing (coldest)
-primers hop on
elongation
-taq polymerase reads 5’ to 3’ and makes other strand (top is opposite of reading direction)
- What do we use PCR for? what do we use gel electrophorysis for
-to copy tons of DNA
-to make sure experiment correct, or match DNA
- What is a tandem repeat?
two of the same sequence right next to eachother
- How does gel electrophoresis differentiate between sequences that have different numbers of tandem repeats?
more repeats, longer, shorter distance
- What is the study of Population Genetics?
study of percentages of items in population
- What is evolution? What is a way we can observe bacterial evolution in a lab?
see which are resistance to antibiotics
- How do we report a frequency? Do we have to report it even if it is 0?
fraction yes
different types of natural selection (survival of the fittest)
stabilizing
-a trend toward the average instead of the extremes
directional
-one extreme is the best
disruptive
-either extreme is better than middle
- Describe the difference between infectious disease and genetic disease.
infectious- caused by pathogen/microbe
genetic- caused by mutations
- Define somatic mutation and germline mutation.
somatic- regular cells, not passed down
germline- mutations in reproductive cells and can be passed down
- What are the 4 types of pathogens that can cause disease?
prokaryotic
-bacteria
viruses
eukaryotic
-parasite (just one cell)
-fungi=yeast=mold
- What is a pathogen? What is pathology?
pathogen- cause of disease
pathology- study of a disease
- Describe the difference between infectious and contagious diseases.
infectious
-you can get disease (UTI)
contagious
-you can spread it (cough)
- Define vector borne disease. Give an example. Is it contagious?
transmitted through something non human (lyme’s through ticks)
- What causes a urinary tract infection? Is it contagious?
no, caused by bacteria
- What is the difference between a prokaryote and a single-celled eukaryote?
prokaryotes
-no organelles
-circular DNA
-no nucleus
single-celled eukaryotes
-has organelles
-has nucleus
- What are the components that a virus always has? What are a few that some have and some don’t?
-capsid (protein)
-nucleic material
-lipid envelope SOMETIMES
antigen vs pathogen
antigen
-piece of pathogen
pathogen
-the intruder
- What is the difference between Gram-positive and Gram-negative bacteria?
gram positive
-peptidoglycan on the outside (only one membrane)
gram negative
-peptidoglycan inside the TWO membranes
- What are the two macromolecules that can make up the outer coating of a virus?
-protein capsid
-lipid envelope
- Define macrophage (MØ)
a WBC that eats harmful cells
-PRRs
-cytokines
- What are Pattern Recognition Receptors (PRR)? What is the response of the cell when the receptor is activated?
when activated, PRR tells nucleus to make cytokines
what are scavenger receptors
a kind of PRR on Macrophages that look for dead cell tissue to bring it in and digest it
- What are cytokines? When are they released?
protein that travel between WBCs for signaling (macrophages)
- How are lysosomes in MØ special?
they have more than just digestive enzymes, they have extra for killing pathogens
Innate vs Adaptive Immune System
Innate
-1st response
-limited
-same response time
-MO, skin, mucus, PRRS
Adaptive
-2nd response (when innate needs backup)
-specific
-gets faster each time
-B & T cells, antibodies
describe how innate triggers help from adapive
-macrophage brings antigen to thymus/lymph node/other
-Tₕ release cytokines to command
-T꜀ prepare to attack
- Explain how the skin, stomach acid, and the mucociliary escalator work to prevent infection.
skin
-physical barrier
mucociliary escalator
-redirects infection to exit either (cough or digest w acid)
cells of innate immunity
Macrophages (phagocytosis)
Polymorphonuclear cells (PMNs)
-Granulocytes (multi-lobe, granules)
—Neutrophils (common, first responder to infection) (phagocytosis & granules)
—Eosinophil (anti-parasite) (only granules)
—Basophil (rare, allergic response) (only granules)
what do different granulocytes look like
neutrophil
-3 lobes spread out
eosinophil (like an E but no middle)
-2 lobes spread
basophil (like a B)
-2 lobes attached
- How does a macrophage kill? how does a granulocyte kill?
macrophage
-phagocytosis (eats then lysosome)
granulocytes (granules)
-little bomb for bad things
- Describe the differences between acute and chronic disease. Give an example for each.
acute
-fast & short (1day - 2wks)
-severe symptoms (you know you’re sick)
chronic
-slow & long (3wks-forever)
-less severe (don’t always know you have it)
-MAY NOT RESOLVE
- What cells correspond to the Innate immune system? What about the Adaptive immune system?
innate immune system
-macrophage, granulocytes
adaptive immune system
-B cells, T cells (Tₕ & T꜀)
- Where do T cells and B cells mature?
T cells
-in the thymus
B cells
-in the bone marrow
what is autoimmunity
-when your immune system mistakes your own body for a threat and starts attacking it.
-negative selection kills the cells that do this
types of lymphocytes
B cell
-secrete antibodies
Tₕ cell (helper)
-binds with macrophage on MHC II
-coreceptor CD4
-helps activate other WBC
T꜀ cell (cytotoxic cells)
-antigen in MHC I
-coreceptor CD8
-kills infected cells
-makes effector and memory cells
what is a BCR (B cell receptor)
an antibody in the membrane
what does a B effector cell do
make tons of antibodies in the ER
What does it mean for a macrophage to present on MHC I vs MHC II
MHC I means it’s infected
MHC II means it ate the infected cell
- How does a Tc know a cell is infected? How does it kill the infected cell?
-when a not self antigen is detected on MHC I
-point mutations till it has TCR that perfectly recognizes antigen (also makes effector and memory cells)
-releases cytokines which trigger apoptosis in infected cell
- Describe the difference between effector T cells and memory T cells.
effector T cells
-the fighters
memory T cells
-linger for later fights
leukocytes vs lymphocytes
leukocytes
-all WBC
lymphocytes
-B & T cells
why are B and T cells “lymphocytes”
they mainly travel in the lymph nodes
- Which cells make antibodies? What are the two kinds of antibodies?
B cells make antibodies
-secreted antibodies
-membrane-bound antibodies
- Diagram an antibody: FAb , FC (what is the purpose of each)
FAb
-varies (specific to antigen)
-antigen bind side
Fc
-constant
-binds to immune cells (virus covered in antigens gets attached to macrophage)
- What is “customized” during B and T cell maturation? Why is this important?
antigen receptors are customized so they can successfully combat different antigens
- What are the 4 things antibodies can do to fight against pathogens? Give a simple diagram/explanation for each.
- agglutination
-antibodies and viruses get all stuck together to they can’t infect the cell - activate c’ proteins (parasites & bacteria)
-antibody attaches to surface protein
-binded c’ protein pokes hole in membrane - opsonize antigens
-antibody on virus makes it easier for FcReceptor on macrophage to grab it for phagocytosis - neutralizing antibodies
-antibodies bind to virus, dig in, and break it up
4 kinds of vaccines
- live - attenuated
-real virus -> can reproduce
-less pathogenic (weaker) - killed/inactivated
-whole virus but DEAD -> no reproduction - RNA
-small nanoparticle fuses and releases RNA into cell that becomes surface protein - subunit
-piece of something
-pray it gets picked up
hematopoiesis
-the creation of new red blood cells
Dr. Robison:
1. What disease does Yersinia pestis cause?
2. What is the purpose of wearing two pairs of gloves?
3. What did it mean when Dr. Robison talked about the suit’s “positive pressure”? Why is that important?
-the black plague
-creates s seal (bacteria can’t get in)
-pathogens would have to get up the suit, which is pushing pressure down the suit
Dr. Johnson:
1. What happens to protein expression when a promoter is wrapped up in a nucleosome?
2. How do acetylation and methylation of the nucleosomes affect protein expression?
3. What is genome metagene analysis?
-it can’t be copied or expressed
-acetylation turns it on, methylation turns it off
-looking at DNA and seeing where the histones are bound, acetylation/methylation, analyze
Dr. O’Neill:
1. What is immunotherapy?
2. What is a macrophage?
3. How does cancer develop?
-treatment using the immune system
-WBC…
-mutations…
