Bio lab exam
Are there any individuals that are genetically identical?
no
What does karyotyping mean?
It is used to determine the number and type of chromosomes present in a sample set of cell.
All females have how many barr bodies?
1
What is a barr body?
The additional X chromosome(s) are purposefully condensed to the point that they are inactive
For a cell to function correctly what must there be
the correct amount of DNA
True or false. sex and gender are the same thing
false they are seperate
What is nondisjunction?
when two chromosomes are not properly separated
during
metaphase. (could be in meiosis I or II)
What are the two common examples of viable autosomal nondisjunction
trisomy 21 - down syndrome
trisomy 18 - Edwards syndrome
What are autosomes?
They are chromosomes 1-22 and have nothing to do with sex determination
What is homogenization?
Physically breaks apart cell membrane, salt removes water from DNA.
-blending strawberries with detergent)
When does DNA replicate?
During the S phase of interphase in cell division
Why was strawberries used in the experiment to extract DNA?
Because it has a lot of DNA making the chromosomes visible to the naked eye.
What stain is used to determine the presence of Y chromosomes?
Acridine orange
How does a nonviable syndrome occur?
0Y
How does jacob's syndrome occur?
XYY
What is the gamete for Klinfelter's syndrome?
XXY (male) - 1 barr body
What is the gamete for Turner's syndrome?
0X (female) - no barr bodies
What does DNA stand for?
Deoxyribonucleic acid
True or false. DNA is found in all living cells?
True
What is the shape of DNA?
A double helix
Where is DNA found in the cell?
The nucleus and mitochondria
What is the role of DNA?
It encodes for all cellular protein (genetic information)
What deproteinization?
Stripping histones away from DNA
-This is stripping histones away from DNA
What is precipitation?
Precipitation is making DNA insoluble so it comes out of solution and can be isolated
-Adding alcohol
DNA is composed of what?
Nucleotides
Nucleotides are made up of what?
sugar, phosphate, and a nitrogen base
The nitrogenius bases are held together by what?
hydrogen bonds
The sugar phosphate backbone is held together by what?
covalent bonds
What are the 2 purines?
Adenine and guanine (2 rings)
What are the 2 pyrimidines?
Thymine and cytosine (1 ring)
What is Chargaffs rule?
A and T pair
G and C pair
Why will DNA look different on each strand?
Because it is antiparallel
What does helicase do?
It unzips the DNA by breaking the hydrogen bonds between nitrogenous bases
What do single-strand binding proteins do?
They keep the two strands of DNA from pairing back together
What does primase do?
It lays down the RNA primer
What does DNA polymerase do?
It synthesizes the new DNA strand. (the main enzyme)
What are the 3 things DNA polymerase needs to work?
1. the parent strand
2. RNA primer
3. free nucleotides
DNA polymerase reads in what direction?
3' to 5' direction and it synthesizes in the 5' to 3' direction
Where does the DNA lagging strand start?
In many places causing Okazaki fragments
What does DNA polymerase I do?
the RNA primer is replaced with DNA in both the leading and lagging strands
What does ligase do?
It glues Okazaki fragments together (bonds them)
Compare DNA and RNA
DNA - ATCG, double stranded, and deoxyribose
RNA - AUCG, single stranded, and just a ribose
What are the steps of DNA replication?
DNA - RNA - Protein
What is the process of transcription?
Going from DNA to RNA.
mRNA carries the message from the nucleus to the cytoplasm
What are the 3 steps of transcription?
1. Initiation - RNA polymerase binds and unwinds DNA
2. Elongation - 1 side of DNA is called the coding strand (5' to 3')
3. Termination - the end of transcription
What is the process of translation?
Going from mRNA to protein. In the ribosomes with codons
What are codons?
A group of 3 amino acids
What are the start codons?
AUG - to start protein synthesis
What are the end codons?
UAA, UAG, UGA
What are the degenerate?
When more than one codon can code for the same amino acid
For RNA what base pair is substituted? And what is responsible for this?
U (uracil) for T
RNA polymerase is responsible for this
Leading vs lagging strand?
Leading - 3' to 5'
Lagging - 5' to 3'
What are the four nitrogenous bases of DNA?
adenine, guanine, cytosine, and thymine
What is evolution?
It is the change in a populations allelic frequency over time?
What is a mendelian population?
Sexual reproducing individuals that are able to interbreed.
What is a gene pool?
a set of genes within a population
What is the Hardy-Weinberg law?
If certain conditions are met, then allelic frequencies in a population will not change form generation to generation.
What is a genetic drift?
When allelic frequencies change with time in small populations.
What is gene flow?
When alleles move from the gene pool of one population to the gene pool of another.
What is a gene?
a coding for a particular trait
What is an allele?
different variations of a gene
What is a genotype?
genetic make-up, alleles present on your chromosome
What is a phenotype?
the visual characteristics that are being expressed
What is homozygous?
Having the same allele for a gene (AA or aa)
What is heterozygous?
Having a different allele for a gene (Aa)
The dominant will be expressed
What is homozygous dominant?
Having the same dominant allele (AA
What is homozygous recessive?
Having the same recessive allele (aa)
Hardy-Weinberg Law only occurs when?
when the population is not evolving
What are the 5 assumptions of the Hardy-Weinberg Law?
1. No specific selection (natural selection)
2. No mutations
3. No migration (gene flow)
4. Large population
5. Random mating
What will happen is one of these conditions is not met?
microevolution
True or false the Hardy-Weinberg Law can determine how far off populations are.
true
What is the allelic frequency formula?
P+q=1
What does p represent?
The frequency of the dominant allele
What does q represent?
The frequency of the recessive allele
What is the genotypic frequency formula?
P^2+2pq+q^2=1
What does p^2 represent?
frequency of homozygous dominant
What does q^2 represent?
frequency of homozygous recessive
What does pq2 represent?
frequency of heterozygous
What is the founder affect?
When a small group breaks off from a large population and becomes isolated.
Compare prokaryotes and eukaryotes
prokaryotes- DNA is circular, no membrane-bound nucleus, no membrane-bound organelles
eukaryotes- membrane-bound nucleus, linear chromosomes, contain organelles, 10x larger than prokaryotic cells
What is the taxonomic hierarchy? (biggest to smallest)
Domain, kingdom, phylum, class, order, family, genus, species
What is the acronym for the taxonomic heircarhy?
Do koalas prefer chocolate or fruit, generally speaking?
How do you classify bacteria?
Using grams stain
What are the 3 domain?
Prokaryotes - Bacteria and archaea
Eukaryotes - Eukarya
Homo sapien - what is the species and genus name
genus -Homo
species - sapien
What are some characteristics of domain archea?
Found in extreme environments (extremophiles), no peptidoglycan, more related to domain eukarya
What are some examples of extremophiles?
Methanogens, Halophiles, Thermoacidophiles
What are methanogens?
Methane makers, in cow guts or swamps
-obligate anaerobes
What are halophiles?
Salt lovers, uses lights- carotenoids(red pigment), in the dead sea
-the simplest form of photophosphorylation and its color is due to bacteriorhodopsin.
What are thermoacidophiles?
low pH and high temp lovers, in hot springs or volcanoes
Characteristic of domain bacteria
Most have either a lot or a little peptidoglycan in the cell wall
What are the 2 groups bacteria can be classified in?
gram positive or negative
Which gram test is harder to treat?
Gram negative because of the outer membrane
What does gram positive or gram negative mean?
Gram negative: very little peptidoglycan in the cell wall, has LPS, and it stains pink/red
Gram positive: a lot of peptidoglycan in its cell wall and stains violet (purple)
What are some characteristics of bacteria?
have ribosomes, capsule(protective outside layer), pilli, flagella
What color does gram positive stain?
Violet (purple)
What are the steps of a grams test?
1. Adding crystal violet to slide
2. Add iodine to bind with crystal violet
3. Add alcohol wash to help decolorize
4. Add counterstain (safranin) to show gram positive or negative
What is the zone of inhibition?
The area in a disc where there is not any visible bacteria.
What is cyanobacteria and where is it located?
A unique type of photosynthetic prokaryote that contains chlorophylllla. It is found in the thylakoid membranes.
What shapes do bacteria come in?
round(cocci), rod-shaped(bacilli), and spiral(spirilla)
What are the 3 bacterial arrangements?
-Staphylo – clusters
-Strepto – chains
-Diplo – pairs
What is the flagella for in domain bacteria?
for movement
What is positive/negative chemotaxis
movement in response to chemicals
What is positive/negative phototaxis
movement in response to light
How do bacteria replicate?
binary fission only
What are the main sources of variation in bacteria?
mutations
What are the 3 ways of genetic recombination in bacteria?
1. Bacteria transformation
2. Bacteria transduction
3. Bacteria conjugation
What is bacteria transformation?
Process of taking in DNA from the external environment. Usually form other bacteria. (a plasmid)
What is bacteria conjugation?
Transfer of DNA using the pilus between two bacterial cells which are temporarily joined
What is bacteria transdcution?
Transfer of DNA between prokaryotes by viruses.
-Uses bacteriophages which are viruses that affect bacteria
What are saprobes?
they feed on dead stuff
What are endospores?
Cells that can withstand harsh environments
What is a plasmid?
Self-replicating circular chromosomes are not associated with the bacteria's normal chromosome. They also help with genetic recombination.
Most bacteria are what?
Heterotrophic - cannot make their own food
What is a photoautotroph (mode of nutrition)?
Energy source - light
Carbon source - CO2
What is a chemoautotroph (mode of nutrition)?
Energy source - oxidation of inorganic chemicals
Carbon source - CO2
What is a photoheterotroph (mode of nutrition)?
Energy source - light
Carbon source - Organic compounds
What is a chemoheterotroph? (most of bacteria are this)
Energy source - Organic compounds
Carbon source -Organic compounds
What is a obligate aerobe?
Requires oxygen (most of bacteria are this)
What is a facultative anaerobe?
Can grow with or without oxygen but grows faster with it
What is a obligate anaerobe?
Poisoned by oxygen. must have no oxygen to grow.
What is symbosis? What are the types?
Ecological relationship between different species in direct contact with each other.
-Mutalism, commmensalism, parasitism, and Ammensalism
What is mutalism?
Both species are benefited. Flower and bee
What is commensalism
One species benefits and one is not affected. Fish and smaller fish
What is parasitism?
One species and benefited and one is harmed. Human and mosquito
What is ammensalism?
One species is negatively affected and one is not affected. Algae and fish
What is the technical name for the species level?
epithet
What does Kingdom Monera mean?
single kingdom
What are the the domains of kingdom Monera?
Archaea and bacteria
What are some characteristics of domain bacteria?
They have no peptidoglycan, they also have a unique lipid construction in their plasma membrane.
Arachea is more closely related to what domain?
eukaryotes
The affect of spices on bacteria growth.
Nothing grows on clove
What are the 4 kingdoms in eukaryotes?
plantae, fungi, protista, and animalia
What are the groupings of domain bacteria?
1. kingdom proteobacteria
2. kingdom chlamydia
3. kingdom spirochetes
4. kingdom cyanobacteria
5. kingdom gram positive bacteria
What is the difference between disinfectant and antiseptic?
Disinfectant - lyses most cells and is used on non living surfaces, ex: lysol wipes
Antiseptic - prohibits growth on some cells and is used on living tissue. ex: rubbing alcohol
Do hardy Weinberg practice problems, know the pictures and know the domains
kk