Bio1 Lab Midterm

What are the steps to the scientifc method?

question, research, hypothesis, experiment, gather data,draw conclusions,

a testable, educated guess or proposed explanation for a phenomenon, often stated as an "if/then" statement, that serves as a starting point for further investigation or experiments

hypothesis

Why must a hypothesis be falsifiable?

so it can be tested through experiments or observations that could prove it wrong

the variable that is deliberately changed or manipulated in an experiment.

independent variable

A variable that is kept constant throughout the experiment to ensure a fair test

control variable

the variable that is measured or observed; it changes

dependent variable

The group or sample that does not receive the experimental treatment; it serves as a baseline for comparison

control sample

A graph showing how much light a substance absorbs at different wavelengths

absorbance spectrum

What value can be determined from an absorption spectrum

wavelength of maximum absorbance

graph that shows the relationship between known concentrations of a substance and their corresponding absorbance value

standard curve

How do you determine an unknown concentration from a standard curve?

Plug in absorbance to y=mx +b

The movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached

diffusion

What does “diffusion down a concentration gradient” mean?

Molecules move from where they are more concentrated to where they are less concentrated

the state where molecules continue to move but are evenly distributed; there is no net movement in any one direction

dynamic equilibrium

How does temperature affect the rate of diffusion?

Higher temperature increases, lower temperature decreases

The diffusion of water molecules across a selectively permeable membrane from low solute concentration to high solute concentration

osmosis

the environment has a higher solute concentration than the cell; water leaves the cell — animal cells shrink, plant cells cytoplasm and plasma membrane shrink

hypertonic

The environment has a lower solute concentration than the cell; water enters the cell — animal cells swell or burst, plant cells swell within their walls

hypotonic

Solute concentration is equal inside and outside the cell; no net water movement — animal cells stay normal, plant cells become flaccid

isotonic

How do animal cells deal with osmosis

kidneys or other bodily systems

How do plant cells deal with osmosis?

cell walls prevent bursting

How do protists deal with osmosis?

contractile vacuoles to pump out water

How do bacteria deal with osmosis?

cell walls prevent bursting

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)

aerobic celluar respiration

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + energy (ATP)

alcohol fermentation

Simple sugars made of one unit; basic building blocks of carbohydrates (examples: glucose, fructose, galactose)

monosaccharide

Sugars made of two monosaccharides joined by a glycosidic bond (examples: sucrose, lactose, maltose).

disaccharide

Large carbohydrate molecules made of many monosaccharides linked together (examples: starch, glycogen, cellulose, chitin)

polysaccharide

6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂

photosynthesis

What are the two main stages of photosynthesis?

light dependent reaction and calvin cycle

occur in the stroma; use ATP and NADPH to fix CO₂ into glucose.

Calvin cycle

occur in the thylakoid membranes; convert light energy to ATP and NADPH and release O₂.

light dependent reaction

The continuous movement of carbon among the atmosphere, living organisms, oceans, and soil through processes like photosynthesis, respiration, decomposition, and combustion

carbon cycle

How do you calculate total magnification

objective x 10

What is the fov in mm for 40x, 100x, 400x, and 1000x

5 2 .5 .2

How do you convert from meters (m) to millimeters (mm)to micrometers(um)?

x 1000 each

How do you convert from liters (L) to milliliters (mL)to microliters(um)?

x 1000 each

What is the organism and is it prokaryotic or eukaryotic? Say if photosynthetic

cyanobacteria anabaena (prokaryote, photosynthetic)

What is the organism and is it prokaryotic or eukaryotic?

lactobacillus sp. (prokaryote)

What is the organism and is it prokaryotic or eukaryotic?

Paramecium sp. (eukaryote)

What is the organism and is it prokaryotic or eukaryotic? State if photosynthetic

Elodea sp. (eukaryote, photosynthetic)

What is the organism and is it prokaryotic or eukaryotic? State if photosynthetic

Solanum tuberosum/ potato (eukaryote, photosynthetic)

What is the organism and is it prokaryotic or eukaryotic? State if photosynthetic

amoebae sp. (eukaryote)

How do you calculate cell size through a microscope?

fov (um)/ # of cells

What is the organism and is it prokaryotic or eukaryotic?

Chlorella vulgaris (eukaryote)

What is the organism and is it prokaryotic or eukaryotic?

Amoeba proteus (eukaryote)

How do you find percent error

experimental-theoretical/theoretical

What are the requirements for a graph

Title, labeled x and y axis with name and units, tick marks on both axes, legend, caption

What are the requirements for a table

numbered, title, subheadings

What are the requirements for a drawing

title, total mag, estimated cell size, labeled cell strucutures

Whats this

micropipette

Whats this

serological pipette

In the egg lab when placed into a _____ solution it will gain mass

hypotonic

In the egg lab when placed into a _____ solution it will lose mass

hypertonic

In the egg lab when placed into a _____ solution its mass will stay the same

isotonic

the concentration of solute particles in a solution

osmolarity

the ability to distinguish two close objects as separate

resolution

difference in light intensity or color between an object and its background

contrast

thickness of the specimen that remains in sharp focus at one time

depth of field

Higher magnification = _______ depth of field

smaller

measure of how much a substance bends (refracts) light

index of refraction

• simple, single-celled organism without a nucleus.

• DNA is free in the cytoplasm

• No membrane-bound organelles

• Usually smaller (1–10 µm)

prokaryote

• cell with a nucleus and membrane-bound organelles.

• DNA is inside the nucleus

• Contains mitochondria, ER, etc.

• Usually larger (10–100 µm)

eukaryote

d of fov1 X mag fov1/mag fov2=

d for fov2

What organelle can you expect to see in an ameobae

contractile vacuole

• plant organelles that store starch.

• Found in storage tissues like potatoes

• A type of plastid

• Can convert starch back into sugar when the plant needs energy

amyloplasts

How do ameobae move

pseudopodia and cytoplasmic streaming

How does paramecium move

cilia

why cell size is limited by the surface area-to-volume ratio

too much volume doesnt allow the export of materials

mitochondria and chloroplasts originated from free-living bacteria that were engulfed by an ancestral eukaryotic cell and became permanent organelles

endosymbiont theory

Whats the evidence for the endosymbiont theory

circular DNA

70S ribosomes, same as prokaryotes

Divide by binary fission

Double membranes

Similar size to bacteria

anaerobic respiration that converts pyruvate into lactic acid and regenerates NAD⁺

lactic acid fermentation

anaerobic process where pyruvate is converted into ethanol and CO₂, while regenerating NAD

alcohol fermentation

C₆H₁₂​O₆→2C₃H₆​O₃+Energy (2 ATP)

lactic acid fermentation

organism that obtains its energy and carbon by consuming other organisms

heterotroph

organism that produces its own food using energy from sunlight (photosynthesis) or chemical reactions (chemosynthesis)

autotroph

Where do the light reactions happen

thykaloids

Where does the Calvin cycle happen

stroma

Sugar forming step of photosynthesis is driven by ATP and NADH but can only occur while light is avaliable

calvin cycle

When light energy from photons is converted to electrochemical energy, water splits to give electrons to the system resulting in the formation of oxygen

light reactions

Does carbon dioxide or oxygen increase during photosynthesis

oxygen

What is DNA made of?

sugar, phosphate group, nitrogenous base

What are the pyrimidines

cytosine and thymine

What are the purines

adenine and guanine

Cut human DNA into fragments

restriction enzymes

How can restriction enzymes determine variation in DNA sequences

They cant cut where there is a mutation making the band longer for gel electrophoresis

What are the origins of restriction enzymes?

they were found in bacteria and cut out viruses

During gel electrophoresis DNA moves towards the positive end because it is ______ charged

negatively

During gel electrophoresis DNA is categorized by size as the ______ molecules travel faster and farther

smaller

A mixture of DNA with known sizes used in gel electrophoresis

marker

If I am preparing to cast a 100 mL 1% gel how much agrose would i need

1g/100 mL

A _____ agrose concentration is ideal when there are larger DNA fragments

lower

What is the purpose of Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS PAGE)

to seperate proteins

Why do some use Polyacrylamide Instead of Agarose

the proteins are too small for agrose

The physical trait of an organism

phenotype

The genetic makeup of an organism

genotype

• segment of DNA that contains the instructions to make a specific protein or RNA molecule

• basic units of heredity

gene

• alternative form of a gene.

• arose because of mutations

allele

For F1 wheter monohybrid or dihybrid it is always…

heterozygous