lab test Flashcards
independent variable
the variable being tested in an experiment
dependent variable
the variable being measured during an experiment
controlled variables
variables that stay the same through the whole experiment (species, amount of food/ water etc.)
replication
every experiment needs to be replicated to ensure similar results
experimental design
comparing what the experimental and control groups will go through
continuous data
can have whole or half numbers (fractions, decimals) is shown by a line graph
experimental control
a group that does not receive any treatment
discrete data
whole numbers only. cannot have any in between numbers. used in bar graphs, bars should not be touching
carbohydrate structure
polymers of polysaccharide monomers. have a 1:2:1 ratio C:H:O
benedicts test
tests for reducing sugars by changing color when it comes into contact with a free ketone or aldehyde group. will turn red/orange when the result is positive
Lugols iodine test
tests for starch in carbohydrates. if positive, solution will turn blue/black
positive control for benedicts test
glucose
negative control
distilled water
why would sucrose test negative (benedicts test)
because sucrose does not have a free ketone or aldehyde group
why does the starch and HCL solution test positive for the benedict test
Because of the addition of the HCl in this solution, it is able to break some bonds and a free ketone or aldehyde group will become free
Biuret test
tests for the peptide bonds (C-N) in proteins will turn violet with a positive test
why do amino acids test negative during biuret test
because amino acids do not have the peptide bonds that proteins have
protein structure
peptide (C-N) bonds
triglycerol
glycerol backbone and three fatty acids
sudan IV test
tests for lipids positive test will have a layer of red or globules
saturated fat
solid at room temperature because they only have single bonds to hydrogen
unsaturated fat
liquid at room temperature (oils) because they have some double bonds to hydrogen
how can you tell if a drink is a diet drink
to test if something is actually diet, you would use benedicts test to test for reducing sugars in the drink
would a soy burger test positive for protein
soy has proteins and therefore peptide bonds. you would use the biuret test for peptide bonds to figure out whether the burger has protein or not
which vegetable enzyme is the most effected by heat
onion, because it changed color to clear the quickest after being added to heat
which vegetable was the least effected by heat
celery was the least effected because it never did turn clear after heat was applied
what is the optimal temp for peroxidase
22 deg C or room temperature produced the deepest blue color(zucchini)
what could happen if an enzyme is out of its optimal temperature
if a enzyme is out of its optimal temperature, it may denature and therefore lose its function
what concentration of amino acid was there a large drop in level of absorbance
5mg aa had the first drop in absorbance for some vegetables, then again at 15mg for the rest of the vegetables
does increasing aa have the same effect on all the vegetables
Essentially increasing amount of ascorbic acid will eventually have the same effect on all enzymes (lower absorbance level) its just a matter of how much it takes to turn the solution clear with ascorbic acid
what color does TMB turn the enzyme
Blue. darker blue = more enzyme activity, lighter blue = less enzyme activity
ecomorphs of anolis lizards
- twig anoles 2. crown giant anoles 3. trunk ground anoles, 4. trunk anoles 5. grass bush anoles 6. trunk crown anoles
ecomorph vs. species
an ecomorph may not be closely related (usually pretty distant) but may look similar because they live in similar habitats. Species may not look alike but are closely related (usually because they habituate in different environments
convergent evolution
different species have habitats in similar environments, so they have similar traits and evolve in similar ways even though they are of different species. Anolis ssagrei and anolis cybotes are from different islands but are both twig anoles, so they both probably evolved in similar habitats and have similar traits
adaptive radiation
organisms / species diversity from one ancestral species by branching off rapidly into new species or ecomorphs
ecomorph
same species living in different habitats and therefore having different traits
nomenclature
first name is class second is italicized and lowercase for species
natural selection
traits make it easier for individuals to survive in their environment, species with non - favored traits will not live very long because they will have better fitness than the other species If NS disturbs H-W equilibrium, evolution will occur
directional selection
one extreme phenotype is favored because of some reason (ex. camoflauge)
speciation
as two populations become genetically different, they become less able to interbreed, so they create an in between ancestor
genetic drift
chance events (sudden change in environment) that changes allele frequencies over time
population size vs. genetic drift
when the population is bigger, genetic drift will take a longer amount of time to have a lager effect, just because there are so many different individuals it has to get through, smaller population = more genetic drive, larger population = smaller amount of genetic drift
stabilizing selection
selection pressures working against extreme phenotypes, favoring normal phenotypes
disruptive selection
selective pressures favoring two extreme phenotypes, working against the normal phenotypes
rules of microscopes
always remove slide, set objective to lowest power, use two hands to carry, wrap cord around oculars, put dust cover on
low objective
4x power, 40 magnification
medium objective
10x power, 100 magnification
large objective
40x power, 400 magnification
field of view calculations
how many squares specimen takes up on graphing slide (1 square = 1 mm) divided by how much space the specimen takes up (ex. 4,25 squares / 2 (half the slide) )
mitosis
occurs in somatic cells (body cells). ends in two daughter cells. no genetic variation. results in two diploid cells
prophase
chromosomes condense in the middle of the nucleus and spindle fibers begin to form
metaphase
chromosomes line up along the centromere and spindle fibers are fully formed and attach to each chromosome on each side.
anaphase
chromosomes are pulled apart into sister chromatids to opposite ends to the cell.
telophase
sister chromosomes are at the end of the cell and the cell begins to split into two
cytokinesis
where the actual cell splits into two. cleavage furrow forms in animal cells to pinch cells apart and cell wall physically separates the cells by forming a wall in the middle of the two cells in plant cells
what stage are cells in the longest
prophase
what stage are cells in the shortest amount of time
anaphase
where does meiosis occur in plants
sporangia
what do plants produce by meiosis
spores (gametes) haploid
what do animals produce by meiosis
sperm / eggs (gametes) haploid
gene
genetic information on a gene
locus
location of a gene on a chromosome
null hypothesis
there is no significant difference between expected and observed results
prediction (mendelian genetics)
if there is no significant difference, we can accept the null hypothesis and expected and actual ratios should be the same
expected ratios for monohybrid cross (without codominance, or incomplete dominance)
3:1
expected ratios for dihybrid cross
9:3:3:1
what could it mean when the expected ratios are incorrect
could mean there was sampling error, or there was co dominance or incomplete dominance present in that allele
expected mendelian ratio for test cross (monohybrid)
1:1:1:1
nucleotide vs amino acid sequence
A nucleotide chain is a chain of base pairs of RNA or DNA (that are nnot linked together) these will have the same percent similarity and percent identity because each dna base can only code for one rna base. amino acids have redundancy so they will not quite match even though they code for the same thing, given the different percent identity and similarity
percent identity
percent of nucleotides or amino acids that are the exact same in a comparison of amino acids or nucleotides
percent similarity
percent of how many nucleotides or amino acids that have the same characteristics. (if one amino acid is large and one is small, it will not count as a similarity, same with hydrophilic vs hydrophobic.)
why is there a difference in percent similarity and percent identity in the amino acid sequence
because of the redundancy in amino acid coding (four nucleotides code for 20 amino acids) the amino acids in two sequences may be similar but they might code for different things or have different characteristics, meaning they are not quite as similar as they may seem
electrophoresis
using small amounts of dna to insert in a well of a container will gel, turning on the electrophoresis and seeing the base pair fragments move down the machine from negative to positive. will show dna matches if fragments are of the same size (same length down the machine)
CRISPR
Clustered Regularly Interspaced Short Palindromic Repeats
Cas genes
genes that code for cas proteins
nucleases
proteins(enzymes) that cut DNA
helicases
unwind dna (enzyme)
parts of the Cas9 system
Cas9, gRNA, host RNA
