Bio 101 Lab Final

independent variable

causes an effect (manipulated by the experimenters)

dependent variable

is effected by the independent variable

Control

all of the factors are the same as the test group, except that the factor being tested is left in its normal, unmanipulated state. Associated with the independent variable, which may influence the dependent variable.

Agar

A polysaccharide compound found in the cell walls of some red algae, created by Robert Koch. Utilized to culture bacteria, causing the medium to gel.

Three Domains

Bacteria, Archaea, Eukarya

Prokaryotes (Archaea, Bacteria)

*unicellular* organisms that lack membrane-bound organelles, including a nucleus.

Eukaryotes

Cells with true nuclei and membrane-bound organelles.

Bacteria two groups:

bacteria and cyanobacteria (blue-green algae)

Two types of autotrophic bacteria

Photosynthetic and chemosynthetic

Photosynthetic bacteria

bacteria that use light as their energy source in a process similar to the photosynthesis in plants. (does not use H20 as a source of electrons, different photosynthetic pigments in structure)

Chemosynthetic bacteria

bacteria that obtain their energy from the oxidation of inorganic substances (ex. sulfur bacteria use hydrogen sulfide as their inorganic substance)

Bacteria shapes

bacilli (rod), cocci (small spheres), spirilla (corkscrew-shaped)

Staphylococcus

gram-positive cocci, may be seen in bunches.

Streptococcus

gram-positive coccus. Chains may be visisble in direct mouth scrapings. Cause of "strep throat"

Bacillus

gram-positive bacillus, many possible species, common genera of discomposers.

Coliforms

gram-negative rods. Common in mammal intestines. ability to ferment lactose.

pseudomonas

bacteria produce severe infections, especially in burn patients

photosynthesis equation

H20 + CO2 + (light) -> (CH20)N + O2

Rf value

Distance substance travels from origin/distance solvent travels from origin

Genetics:

(e) - expected value; ex. 9:3:3:1, 1:1:1:1
(o) - observed value;
Deviation- (o-e) = d
Chi sqaure, square all d's and add them and divde them by e; Alld^2/e = chisquare

Law of Segregation

that for diploid organisms, each homologous chromosome has an equal chance of being passed on to a given gamete.

Law of independent assortment

that in meiosis nonhomologous chromosomes assort into gametes independently from another.

Analyzing Chi Square

(df = # of cases minus one)
P < .20 (right) = less likely by chance (reject)
P > .05 (left) = due by chance (support

Klinefelter's male

XXY; unusual body proportions and sterility, subnormal mental ability

Turner's female

XO; Short Stature, webbing of the neck, may have low mental ability and sterility

Super Female

XXX; May have low mental ability; fertile

"Cri du chat"

defective chromosome #5; catlike cry, severe physical and mental abnormalities, non-lethal

Palau's syndrome

extra chromosome #13; physical abnormalities, lethal soon after birth

Edward's syndrome

extra chromosome #18; unusual features of the head and fingers; often dies in infancy.

Down's syndrome

extra chromosome #21; characteristic facial features, low mental ability, stocky build, sometimes heart defects.

XYY Condition

XYY; may have some above average height

Why are sex-linked genes much higher in frequency in males than females?

All sex-linked conditions are recessive, a male needs only to receive a single copy of a recessive gene for a sex-linked trait to be expressed phenotypically. A female needs two recessive copies to express the trait.

Turner's syndrome

a genetic defect in which affected women have only one X chromosome, causing developmental abnormalities and infertility.

Genetics of Breast Cancer

Gene-related; Broca 1 and 2

Cystic Fibrosis

autosomal recessive, causes a build-up of mucus, causes lung infections.

Sickle Cell Anemia

Autosomal recessive, Causes red blood cells to change shape and cause a build-up of sickle cells and loss of red blood cells.

PKU

Autosomal recessive, a birth defect that causes an amino acid called phenylalanine to build up in the body.

Is DNA negatively charged or positive?

Negatively charged

Electrophoresis

procedure that separates pieces of DNA by molecular size and shape so they can be viewed a​nd identifed.

Agarose

made up of sugars that form crosslinks which form pores in the gel matrix. These pores allow for separation of substances by size.

PCR (polymerase chain reaction)

makes many copies of a particular segment of DNA. This synthesis allows scientist to look at differences in DNA between one person or organism and another.

Why is gel electrophoresis viewed under light?

The light allows one to see the DNA fragment and compare how far apart they are form each other.

What happens in electrophoresis because DNA is negatively charged?

DNA molecules are negatively charged because of negatively charged phosphate groups in DNA backbone. They will migrate toward the positive electrode.

Gel electrophoresis fragment charge

Longer fragments = negative
Shorter fragments = positive

Why is PCR used in Gel Electrophoresis?

1) it makes many copies from a DNA strand 2) it selectively amplifies only the parts of the human genome (the DNA) that is under examination

Enzyme used in PCR?

Taq Polymerase

Why is Taq Polymerase an ideal enzyme for PCR?

It is stable enough to withstand dramatic temperature changes needed for the DNA to be replicated a number of times

What is the gel used in gel electrophoresis? Why?

Agarose (substance found in seaweed). This is used because Agarose is electrically neutral (has no charge)

Why must you pour a buffer solution over the gel in gel electrophoresis?

Because the ions in the buffer solution conduct electricity during electrophoresis.

What must be added to the DNA samples in gel electrophoresis

The samples must have a dye in it (although the DNA itself is NOT stained)

What kind of enzymes cut DNA that has been copied multiple times?

Restriction Enzymes

Restriction Enzymes

DNA cutting enzymes found in bacteria that cut DNA apart when they come across certain sequences of DNA bases.

Features of Molluscs

mantle, radula, large ventral foot

mantle

thin, fleshy layer that secretes a hard shell

radula

a rasp-like structure in the mouth, is used for scraping algae and drillings into hard shells of other molluscs as seen in predatory gastropods.

hypothetical ancestral mollusk

suggest that the diversity of molluscs came about by modifications form a single ancestor

Chiton

(Class Polyplacophora)
-elongated, flattened body protected by segmented *shells* secreted by the *mantle*
-use their ventral foot for clinging to rocks
-radula used for scraping
-move rapidly and curl into a ball if disturbed.
-no siphon
-scavenger
-uses foot for locomotion

Clam

(Class Bivalvia)
-sedentary, uses foot to bury themselves
-filter feeders, no radula
-mantle secretes the shell
-two siphons, 1 filters food and water through the gills and then into the mouth, the other carries water away.
-gills used for respiration and feeding.
-siphon is a modification of the mantle

Snail

(Class Gastropoda)
-largest class of mollusks
-only mollusk found in terrestrial environments
-scavenger/ predator (radula)
-Snail: stomach-foot
-outer shell; asymmetrical;
-no siphon
-broad foot covering in mucus, mucus helps with locomotion
-operculum in aquatic snails assist in preventing drying out.
-different shaped mantles.
-undergoes torsion during development to give ability to retract into the shell if in danger.

Squid

(Class Cephalopoda)
-most active group of mollusks
-no outer shell, the shell is reduced and internalized.
-fusion of head and foot results in more efficient swimming.
-no radula, but they are tentacles to catch prey while the arms hold prey so it can be eaten.
-mouth lies within the arms.
-siphon for locomotion
-siphon is a modification for the foot, unlike clam which is a modification of the mantle.

Four Tenants of Natural Selection

1. limited resources
2. variation between organisms
3. difference in fitness
4. reproduction

Evolution

change in genotype frequency in a population from one generation to the next.

Genetic variation

Differences among individuals in the composition of their genes or other DNA segments

Differential reproduction

Phenomenon in which individuals with adaptive genetic traits produce more living offspring than do individuals without such traits.

Natural selection leads to....

evolution

Gram Staining

Technique to identify bacteria; bacteria have strong cell walls that surround the cell membrane and provide protection made up of disaccharide sugars.
-Gram-positive cell is thick and stain purple
-Gram-negative cell wall is thinner and partially dissolved so does not retain stain

Enzymes

make reactions in cells go at a speed necessary to maintain life.
-remain unchanged or unconsumed during reaction
-act a catalyst in reactions
-brings down activation energy to speed up the reaction occurring
-proteins

substrate

the molecule that will be acted upon and is changed by the enzyme. Add -as suffix to substrate term to identify specific enzyme.

Enzyme reaction: Catechol

Catechol + 1/2O2 -> (Catecholase) Benzoquinone + H2O

benzoquinone

deters pathogens in damaged tissue in plants, is produced when the catechol in the cells is exposed to oxygen.
-brownish-orange color

spectrophotometer: measures absorbance

Set to 540 nm, this wavelength of light corresponds to green, since green is not a color seen with the conversion of catechol to benzoquinone. Therefore, the green wavelength of light is absorbed rather than reflected

Control

contained enzyme, h20, and catechol (no chelating agent); allows correct cofactors to bind to substrate

Cofactor

A nonprotein molecule or ion that is required for the proper functioning of an enzyme. Often inorganic, nonprotein helpers such as zinc, iron, or copper

Chelating Agents

a group of compounds that bind metallic ions and change the shape of the cofactor

Chelating agents in experiment

PTU (chelating agent) à Copper (cofactor)

Citric Acid (chelating agent) à Copper (cofactor)

EDTA (chelating agent) à Calcium and Magnesium (cofactor)

Why/how are we testing cofactors?

If the removal of an ion prevents enzymatic activity, then we can assume this ion is a necessary cofactor needed for reaction to occur

PTU

organic compound that has a bitter taste and is used as a common safe genetic taste test in humans. Treats hyperthyroidism by inhibiting an enzyme that is normally involved in thyroid hormone synthesis. Structure allows it to bind to copper, used in silver polishing.

EDTA

Used in food contents as a preservative, Ca and Mg ions bind to enzymes for the production of many bacteria and fungi, which spoil food.

Citric acid

natural preservative in citrus fruits and is also used to clean copperbare and to soften water. takes copper away from enzyme and lowers pH of a solution. used to clean copper-ware.

urogenital papilla

female pig: a small bud-like protrusion, just above the anus.

Scrotum

male pig: two slightly rounded patches (testes), then find the male urogenital opening on a small mound just posterior to the umbilical cord.

epitrichium

filmy white layer of waxy material peeling off.

what separates the thoracic cavity and the abdominal cavity

diaphragm

liver

-abdominal cavity, considered part of the digestive system, though food does not pass through it. The liver processes blood from the intestines, the blood that is filled with nurtients and other substances absorbed from the digestive system.

gall bladder

stores bile produced in the liver. one of the components of bile is a by-product of the breakdown of hemoglobin.

Small intestine

Digestive organ where most chemical digestion and absorption of food takes place

Bile duct

The gal bladder empties its contents into the small intestines using the bile duct. connected the gall bladder and the small intestine

stomach

sac-like organ anterior to the small intestine

meconium

greenish-black material formed mostly from amiotic fluid and sloughed-off cells, that fills fetal digestive system. (inside stomach)

spleen

part of the immune system; left of stomach, looks like tongue. it is involved in breaking down blood cells.

What is separating the stomach and the small intestine?

the pyloric sphincter, a circular muscle which prevents back flow of contents from the intestine to the stomach.

Ring of smooth muscle fibers around the opening of the stomach into the duodenum

What is between the stomach and the duodenum (first loop of the small intestine)?

the pancreas, an organ which has both digestive and endocrine function. white granular organ held in placed by the mesentery membrane.

The first is an exocrine role: to produce digestive enzymes and bicarbonate, which are delivered to the small intestine via the pancreatic duct. The second is an endocrine role: to secrete insulin and glucagon into the bloodstream to help regulate blood glucose levels.

What is the mesentery membrane part of?

the peritoneum, which lines the body cavity.

Caecum

near large intestine and the anus.

epiglottis

keeps the respiratory and digestive systems separate.

glottis

below the epiglottis is the glottis, the epiglottis is activated during swallowing to cover the glottis which is the opening to the respiratory system.

thoracic cavity

also known as the chest cavity or thorax, surrounds and protects the heart and lungs

abdominal cavity

Contains stomach, intestines, spleen, and liver, and other organs

diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathin

large intestine

- About 6 feet long and is composed of the caecum, colon, rectum and anus.