Biology Final Exam Review

Microscopes

Total Magnification = eyepiece X objective lens Eyepiece is always 10x If your objective lens is 40x, then total

magnification = 10x X 40x, which is 400x.

pH

The measure of how acidic or basic a substance is.

pH < 7 is acidic (fruit juice, soda, stomach acid).

pH = 7 is neutral (water). pH > 7 is basic (household cleaners).

Scientific Method

Parts of an Experiment Independent Variable – whatever you are testing

for; goes on X-axis Dependent Variable – whatever you are

observing, counting, or measuring at the end; goes on y-axis

Control – whatever is normal, whatever one you leave alone

Constants – the things that are the same in all groups.

Trials – the number of times you run an experiment.

Why Are Cells So Small?

A cell takes in materials via it’s cell membrane. Therefore, the larger the surface area of the cell membrane, the more efficiently it can take in nutrients.

However, if a cell gets too big it’s volume grows faster than it’s surface area and it won’t be able to take in enough nutrients or get rid of enough waste to survive.

Are Viruses Alive?

NO!!! They are not made of cells!!! This is why antibiotics will not help you

if you are sick because of a virus. You can’t kill something that was never alive in the first place.

Antibiotics are for illnesses caused by bacteria, NOT viruses!

Homeostasis

Maintaining a constant internal environment regardless of the external environment. Usually it refers to maintaining a constant

temperature and pH.

Energy The source of energy for most living things is the

SUN!!! The SUN is the catalyst for photosynthesis. (plants,

algae, and certain bacteria) 6CO2 + 6H2O C6H12O6 + 6O2

Carbon Dioxide and Water in the presence of sunlight yields Glucose and Oxygen.

The products of photosynthesis are the reactants for cellular respiration. C6H12O6 + 6O2 6CO2 + 6H2O + ATP

ALL LIVING THINGS DO CELLULAR RESPIRATION!!! The energy in all living things is ATP.

Cells: Animal VS. Plant

Things in Common

Both animal & plant cells have the following main organelles: Nucleus – holds DNA Mitochondria – cellular respiration Ribosomes – makes proteins Cell Membrane – semi-permeable

How Are Plant Cells Different?

Usually rectangular in shape Cell Wall – gives plants their shape Chloroplasts - photosynthesis Extremely large vacuoles – storing

water

Mitosis VS. Meiosis

When one cell divides to become two. Used for growth and

repair. The two daughter cells

maintain the same number of chromosomes as the parent cell.

Humans normally have 46 chromosomes; 47 if you have Down’s Syndrome.

When one cell divides to become four. In females, three of the cells die, leaving only one viable cell. Used for making gametes

(sperm & eggs) The four daughter cells

have half as many chromosomes as the parent cell.

Humans normally have 23 chromosomes in their gametes.

Diffusion When a substance moves into or out

of a cell from a high concentration to a low concentration.

When that substance is water, we call it osmosis.

Enzymes

Type of protein. Act as a catalyst in living things to speed up

chemical reactions. (ex. – digestion) Whatever the enzyme is breaking down is called the

substrate, and must fit with it like a puzzle piece. During the reaction, the substrate is broken down,

but the enzyme retains its shape and can be used again.

Require very specific temperature and pH. If the temperature or pH is too high or too low, the reaction

will slow down!!!

Macromolecules Carbohydrates

Give your body energy Building blocks are monosaccharides

Mono – glucose Di – sugar Poly – starch, fiber

Any food that grows from the ground Proteins

Build muscle and help you heal Building blocks are amino acids Any food that comes from an animal & soy

Lipids Make up cell membranes; insulation; stores energy Building blocks are fatty acids and glycerol Animal fat, butter, oils

Nucleic Acids Stores genetic information Building blocks are nucleotides DNA & RNA

Genetics

DNA Double stranded

(double helix) Nitrogenous bases are

Cytosine, Guanine, Adenine, Thymine C = G A = T

Cannot leave the nucleus.

RNA Single stranded Nitrogenous bases are

Cytosine, Guanine, Adenine, Urasil C = G A = U

Leaves the nucleus.

How Does DNA Work? DNA codes for proteins (amino acids).

Proteins are expressed as traits. Know how to read the amino acid

chart!

Genetics

Genotype A type of gene. Represented by

two alleles (BB, Bb, bb)

BB – homozygous dominant

Bb – heterozygous Bb – homozygous

recessive

Phenotype The physical trait

(brown hair, blue eyes, lactose intolerant, etc.)

Sex-Linked Traits

Only on the X chromosome. Female = XX Male = XY Females are less likely to be affected

because they have a back-up X, males do not.

Females can be carriers if they have the allele on only one X. This means that the female does not have the trait herself, but can still pass it on to her children.

CoDominance – Blood Types

Genotypes AA or AO BB or BO AB OO

Phenotypes A B AB O

Blood type O is the universal donor. This means that regardless of what blood type you have, your body will accept O type blood. Blood type AB is the universal receiver. This means that if you have AB blood, they can give you any blood type and your body will accept it.

Pedigrees

Pedigrees

Traces the history of a trait through a family. Circles = females Squares = males Colored in = affected (they have the trait) Connecting Line = they have children

together

Gel Electrophoresis

A way to test DNA to determine evolutionary relatedness, paternity, or guilt/innocence in instances of crime.

The bands represent fragments of DNA.

For paternity, half the DNA bands must match the child’s DNA bands.

To determine guilt in a court of law, the evidence DNA bands must match the suspect DNA bands EXACTLY!!!

Evolution & DNA

The more similar the DNA the more closely they are related.

The more different the DNA the more distantly they are related.

Charles Darwin Traveled to the Galapagos Islands, most known for

studying birds and giant tortoises. He noticed that the birds on different islands had

different beaks because they had adapted to eating the type of food found on that particular island.

Darwin concluded that all the birds must have evolved from the same common ancestor.

Evolution by Natural Selection

1. Overproduction 2. Competition – food, water, space,

mates 3. Variation – caused by mutation

and/or sexual reproduction 4. Reproduction 5. Speciation

Taxonomy

All stores. Wal-Mart Food Side Cereal Aisle Post Brand Cereal Pebbles Cocoa Pebbles

Food Chain VS. Food Web

Law of Thermodynamics

Matter and energy are neither created nor destroyed, just recycled. Food Pyramids Water Cycle Carbon Cycle Nitrogen Cycle

Ecological Relationships

Mutualism – both benefit; clownfish and sea anemone

Commensalism – one benefits, the other is unaffected; algae growing on the back of a turtle

Parasitism – one benefits, the other is harmed (often killed); tapeworm and human

Biotic VS. Abiotic Factors

Biotic – things that are alive; animals, people, plants, bacteria

Abiotic – things that aren’t alive; water, temperature, pH

Humans & Animals

The greatest impact that humans have on wildlife is habitat destruction!!!

When humans use insects or other animals to control a pest population, that is an example of a biological control. Ex. – Farmers in the vineyards of South America

use chameleons to control the insects that try to damage the grape crops.

BCR #1

Genetics – Huntington’s Disease A dominant disease that shows no signs or

symptoms until age 30-40. Symptoms include decreased mental function, loss of muscle control, etc. There is no cure.

Since this is a dominant disorder (H), a person with Huntington’s must also have at least one parent with the same disease (HH or Hh). A person without Huntington’s is hh.

Some children of Huntington’s parents choose to be tested at a young age while others prefer not to find out.

Know how to do a Punnett Square for Huntington’s!!!

Would you get tested? Advantages

You would know for sure whether you have the disease or not.

You will be able to plan for the future accordingly.

You will know the chances of passing the disease to your offspring.

Disadvantages Some people who

find out that they have Huntington’s cannot handle knowing.

The tests can be expensive and sometimes inaccurate.

If Ron has Huntington’s, he may not be able to continue to receive health insurance.

BCR #2 - Energy Pyramids The sun is the original source

of almost all the energy on the planet. (photosynthesis)

The available energy and biomass decreases by 90% with every step of the pyramid. (Only 10% gets passed on!)

The higher you are on the pyramid, the more food you have to eat in order to get the same amount of energy.

Producers (autotrophs) are always at the bottom, then primary consumers (heterotrophs), then secondary consumers (heterotrophs), then tertiary consumers (heterotrophs).

BCR #3 - Microscopy

Making a wet mount slide. 1. Wash and dry slide and cover slip. 2. Place one drop of pond water onto the

slide. 3. Let the cover slip drop onto the slide at

a 45°angle.

BCR #3 Continued

Using the Microscope 1. Always carry it using two hands. 2. Plug it in. 3. Place the slide on the stage. 4. Adjust the diaphragm to control the amount of

light. 5. Use the lowest power objective lens and the

coarse adjustment knob to focus. 6. Once in focus, you can switch to a higher

power and use the fine adjustment knob.

BCR #3 Continued

Making a Biological Drawing 1. Draw exactly what you see. 2. Always give it a title. 3. Always write your total magnification. 4. Use labels i.e., cell membrane,

ribosomes, flagella, etc. 5. Sign your drawing.