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Biology Exam - 2 Cheat Sheet by

Review Sheet for the 2nd Biology Exam

Global Warming

What is climate and climate change?
The statistics of the atmosphere and the change of those statistics over a period of time.
What are the causes of climate change?
Earth's Position : Angle of Earth's axis Shape of Earth's orbit around sun Solar Energy (sunspots) Volcanic Activity (gas & ash filter sun's rays) Movement of the Continents (Pangaea affected the global pattern of winds & ocean currents)
What is Ozone?
A form of oxygen that has three oxygen atoms in each molecule instead of the usual two.
What is Tropho­spheric Ozone?
"bad ozone"; secondary pollutant - not emitted directly regional air pollutant: cannot trace the source of original ozone national level: 10-15 ppb; high episodes common in the summer 100-200% increase in last century - industrial rev.

Air Pollution

What is Air Pollution?
Various chemicals (gases, liquids, solids) present on the atmosphere in high enough levels to be harmful to humans, other organisms, or material.
Sulfur Oxides
Sulfur oxides (SOx) - partic­ularly sulfur dioxide, a chemical compound with the formula SO2. SO2 is produced by volcanoes and in various industrial processes.
Nitrogen Oxides
Nitrogen oxides, partic­ularly nitrogen dioxide, are expelled from high temper­ature combus­tion, and are also produced during thunde­rstorms by electric discharge.
Carbon Monoxide
CO is a colorless, odorless, toxic yet non-ir­rit­ating gas.
Volatile organic compounds
VOCs are a well-known outdoor air pollutant. They are catego­rized as either methane (CH4) or non-me­thane (NMVOCs).
Harmful to the ozone layer; emitted from products are currently banned from use.
Secondary Sources of Air Pollution
Stationary sources include smoke stacks of power plants, manufa­cturing facilities (facto­ries) and waste incine­rators, as well as furnaces and other types of fuel-b­urning heating devices.
Photoc­hemical Smog
Browni­sh-­orange haze formed by chemical reactions involving sunlight, nitrogen oxide, and hydroc­arbons.

Types of Ecosystems

Temperate Deciduous Forests
are dominated by trees that lose their leaves each year. They are found in areas with warm, moist summers and mild winters.
Shortgrass Prairie
Wester­nmost grasslands of the Great Plains, charac­terized by infrequent rainfall, low humidity, and high winds; dominated by shallo­w-r­ooted, sod-fo­rming grasses
ype of biome where the tree growth is hindered by low temper­atures and short growing seasons.
also known as boreal forest or snowfo­rest, is a biome charac­terized by coniferous forests consisting mostly of pines, spruces and larches.
A savanna or savannah is a grassland ecosystem charac­terised by the trees being suffic­iently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses.
It is shaped by a Medite­rranean climate (mild, wet winters and hot dry summers) and wildfire, featuring summer­-dr­ought tolerant plants with hard sclero­phy­llous evergreen leaves, as contrasted with the associated soft-l­eaved, drought deciduous, scrub community of Coastal sage scrub, found below the chaparral biome.
Alpine climate is the average weather (climate) for a region above the tree line. This climate is also referred to as a mountain climate or highland climate.


A biomol­ecule is any molecule that is produced by a living organism, including large macrom­ole­cules such as proteins, polysa­cch­arides, lipids, and nucleic acids, as well as small molecules such as primary metabo­lites, secondary metabo­lites, and natural products.
Types of biomol­ecules
Small molecules: Lipids, polysa­cch­arides, glycol­ipids, sterols, glycer­olipids Vitamins Hormones, neurot­ran­smi­tters Metabo­lites
Monosa­cch­arides are the simplest form of carboh­ydrates with only one simple sugar. They essent­ially contain an aldehyde or ketone group in their structure.
are formed when two monosa­cch­arides, or two single simple sugars, form a bond with removal of water. They can be hydrolyzed to yield their saccharin building blocks by boiling with dilute acid or reacting them with approp­riate enzyme­s.[1] Examples of disacc­harides include sucrose, maltose, and lactose.
are polyme­rized monosa­cch­arides, or complex carboh­ydr­ates. They have multiple simple sugars. Examples are starch, cellulose, and glycogen.
Lignin is a complex polyph­enolic macrom­olecule composed mainly of beta-O­4-aryl linkages.
Lipids (oleag­inous) are chiefly fatty acid esters, and are the basic building blocks of biological membranes.
Amino acids
Amino acids contain both amino and carboxylic acid functional groups. (In bioche­mistry, the term amino acid is used when referring to those amino acids in which the amino and carbox­ylate functi­ona­lities are attached to the same carbon, plus proline which is not actually an amino acid).
Protein structure
The particular series of amino acids that form a protein is known as that protein's primary structure. This sequence is determined by the genetic makeup of the indivi­dual. It specifies the order of side-chain groups along the linear polype­ptide "­bac­kbo­ne".


Agricu­lture Definition
Agricu­lture is the cultiv­ation of animals, plants, fungi, and other life forms for food, fiber, biofuel, medicinals and other products used to sustain and enhance human life.
Crop cultiv­ation systems
Cropping systems vary among farms depending on the available resources and constr­aints; geography and climate of the farm; government policy; economic, social and political pressures; and the philosophy and culture of the farmer
Further indust­ria­liz­ation led to the use of monocu­ltures, when one cultivar is planted on a large acreage. Because of the low biodiv­ersity, nutrient use is uniform and pests tend to build up, necess­itating the greater use of pesticides and fertil­izers.
Multiple cropping, in which several crops are grown sequen­tially in one year, and interc­rop­ping, when several crops are grown at the same time, are other kinds of annual cropping systems known as polycu­ltures.
Livestock production systems
Livestock production systems can be defined based on feed source, as grassl­and­-based, mixed, and landle­ss.[94] As of 2010, 30% of Earth's ice- and water-free area was used for producing livestock, with the sector employing approx­imately 1.3 billion people.
Selective Breeding
During the second half of the 20th century, producers using selective breeding focused on creating livestock breeds and crossb­reeds that increased produc­tion, while mostly disreg­arding the need to preserve genetic diversity. This trend has led to a signif­icant decrease in genetic diversity and resources among livestock breeds, leading to a corres­ponding decrease in disease resistance and local adapta­tions previously found among tradit­ional breeds.
Mixed Production Systems
Grassland based livestock production relies upon plant material such as shrubland, rangeland, and pastures for feeding ruminant animals. Outside nutrient inputs may be used, however manure is returned directly to the grassland as a major nutrient source.
Production practices
Tillage is the practice of plowing soil to prepare for planting or for nutrient incorp­oration or for pest control. Tillage varies in intensity from conven­tional to no-till. It may improve produc­tivity by warming the soil, incorp­orating fertilizer and contro­lling weeds, but also renders soil more prone to erosion, triggers the decomp­osition of organic matter releasing CO2, and reduces the abundance and diversity of soil organisms.
Pest Control
Pest control includes the management of weeds, insects, mites, and diseases. Chemical (pesti­cides), biological (bioco­ntrol), mechanical (tillage), and cultural practices are used. Cultural practices include crop rotation, culling, cover crops, interc­rop­ping, compos­ting, avoidance, and resist­ance. Integrated pest management attempts to use all of these methods to keep pest popula­tions below the number which would cause economic loss, and recommends pesticides as a last resort.
Water Management
Water management is needed where rainfall is insuff­icient or variable, which occurs to some degree in most regions of the world.[92] Some farmers use irrigation to supplement rainfall. In other areas such as the Great Plains in the U.S. and Canada, farmers use a fallow year to conserve soil moisture to use for growing a crop in the following year.[105] Agricu­lture represents 70% of freshwater use worldwide.

Population Profiles

What Factors Affect Birth Rates and Fertility Rates
Importance of children as a part of the labor force. Urbani­zation. Cost of raising and educating children. Availa­bility of reliable birth control methods.
Is considered to be the breeding group for an organism. Charac­ter­istics include: Birth rate, death rate, rate of natural increase and age-sex distri­bution.
Total fertility rate (TFR)
In a popula­tion, the number of births per woman
Population Profile
Population Profiles for Developing and Developed Countries -snapshot of population at a given time
Minimal Viable Population
The smallest population size at which a species is able to sustain its numbers and survive.
calculate rate of population increase2
rate = births­–de­aths/N
Carrying Capacity
largest number of indivi­duals of one species that an ecosystem can support over time

Golgi Apparatus

A warehouse for receiving, sorting, shipping and even some manufa­cturing products of the ER such as proteins are modified and stored then sent to other destin­ations.

Comparison of Prokar­yotes vs. Eukaryotes

A eukaryote is any organism whose cells contain a nucleus and other structures (organ­elles) enclosed within membranes.

A prokaryote is a single­-celled organism that lacks a membra­ne-­bound nucleus (karyon), mitoch­ondria, or any other membra­ne-­bound organe­lles.

Function of the Cell Membrane

The cell membrane also plays a role in anchoring the cytosk­eleton to provide shape to the cell, and in attaching to the extrac­ellular matrix and other cells to help group cells together to form tissues.
The cell membrane is select­ively permeable and able to regulate what enters and exits the cell, thus facili­tating the transport of materials needed for survival.
The movement of substances across the membrane can be either "­pas­siv­e", occurring without the input of cellular energy, or "­act­ive­", requiring the cell to expend energy in transp­orting it.
Passive Osmosis
Some substances (small molecules, ions) such as carbon dioxide (CO2) and oxygen (O2), can move across the plasma membrane by diffusion, which is a passive transport process.
Protein Channels
Nutrients, such as sugars or amino acids, must enter the cell, and certain products of metabolism must leave the cell.
Endocy­tosis is the process in which cells absorb molecules by engulfing them.
Just as material can be brought into the cell by invagi­nation and formation of a vesicle, the membrane of a vesicle can be fused with the plasma membrane, extruding its contents to the surrou­nding medium.

Cell Structure

Fluid mosaic model
Biological membranes can be considered as a two-di­men­sional liquid in which lipid and protein molecules diffuse more or less easily.
Lipid bilayer
Lipid bilayers form through the process of self-a­sse­mbly.
The cytosk­eleton is found underlying the cell membrane in the cytoplasm and provides a scaffo­lding for membrane proteins to anchor to, as well as forming organelles that extend from the cell.


Plasma membranes also contain carboh­ydr­ates, predom­inantly glycop­rot­eins, but with some glycol­ipids (cereb­rosides and gangli­osi­des).
The cell membrane has large content of proteins, typically around 50% of membrane volume[11] These proteins are important for cell because they are respon­sible for various biological activi­ties.
The cell membrane consists of three classes of amphip­athic lipids: phosph­oli­pids, glycol­ipids, and sterols. The amount of each depends upon the type of cell, but in the majority of cases phosph­olipids are the most abunda­nt.[10] In RBC studies, 30% of the plasma membrane is lipid.

Lipid Bilayer

Lipid Bilayer
The lipid bilayer is a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells.
Ion Transp­orter
A transm­embrane protein that moves ions across a plasma membrane against their concen­tration gradient, in contrast to ion channels, where ions go through passive transport.
In many naturally occurring bilayers, the compos­itions of the inner and outer membrane leaflets are different. In human red blood cells, the inner (cytop­lasmic) leaflet is composed mostly of phosph­ati­dyl­eth­ano­lamine, phosph­ati­dyl­serine and phosph­ati­dyl­ino­sitol and its phosph­ory­lated deriva­tives.
At a given temper­ature a lipid bilayer can exist in either a liquid or a gel (solid) phase. All lipids have a charac­ter­istic temper­ature at which they transition (melt) from the gel to liquid phase.


Osmosis Definition
Osmosis is the sponta­neous net movement of solvent molecules through a partially permeable membrane into a region of higher solute concen­tra­tion, in the direction that tends to equalize the solute concen­tra­tions on the two sides.
Osmotic Pressure
To be the minimum pressure required to maintain an equili­brium, with no net movement of solvent.
Permea­bility depends on solubi­lity, charge, or chemistry, as well as solute size.
Plasmo­lysis is the process in which cells lose water in a hypertonic solution.
Suppose an animal or a plant cell is placed in a solution of sugar or salt in water.
If the medium is hypotonic relative to the cell cytoplasm — the cell will gain water through osmosis. If the medium is isotonic — there will be no net movement of water across the cell membrane. If the medium is hypertonic relative to the cell cytoplasm — the cell will lose water by osmosis.

Adenosine tripho­sphate

Adenosine tripho­sphate (ATP) is a nucleoside tripho­sphate used in cells as a coenzyme.

It is often called the "­mol­ecular unit of curren­cy" of intrac­ellular energy transfer.


Are the most diverse carbon compounds in living organisms. Proteins are polymers of amino acids. At least 20 amino acids are used to build proteins and all have same basic structure. Function of protein is influenced by its overall shape.

Cell Theory

Polype­ptide chain
Each of these consists of a linear sequence of amino acids connected end to end.
The combin­ation of DNA and proteins that consti­tutes eukaryotic chromo­somes; often used to refer to the diffuse, very extended form taken by chromo­somes when a cell is not dividing.
Smooth Endopl­asmic Reticulum (smooth ER)
Located in cytoplasm Found in all Eukaryotic cells Stores and supplies lipids for cell.
A type of nucleic acid consisting of a polynu­cle­otide made up of nucleotide monomers with a ribose sugar and the nitrog­enous bases adenine, guanine, uracil, & cytosine; usually single stranded; functions in protein synthesis, genes regula­tion, & as the genome of some viruses.
Rough Endopl­asmic Reticulum
The surface of the rough endopl­asmic reticulum (often abbrev­iated RER or Rough ER) is studded with protei­n-m­anu­fac­turing ribosomes giving it a "­rou­gh" appearance (hence its name).

Prokar­yotic Cell Structure

A prokar­yotic cell has three archit­ectural regions:

On the outside, flagella and pili project from the cell's surface. These are structures (not present in all prokar­yotes) made of proteins that facilitate movement and commun­ication between cells.

Enclosing the cell is the cell envelope – generally consisting of a cell wall covering a plasma membrane though some bacteria also have a further covering layer called a capsule. It also prevents the cell from expanding and bursting (cytol­ysis) from osmotic pressure due to a hypotonic enviro­nment.

Inside the cell is the cytopl­asmic region that contains the genome (DNA), ribosomes and various sorts of inclus­ions. Prokar­yotes can carry extrac­hro­mosomal DNA elements called plasmids, which are usually circular. Plasmids encode additional genes, such as antibiotic resistance genes.

Protein Synthesis

Cells are capable of synthe­sizing new proteins, which are essential for the modulation and mainte­nance of cellular activi­ties. This process involves the formation of new protein molecules from amino acid building blocks based on inform­ation encoded in DNA/RNA. Protein synthesis generally consists of two major steps: transc­ription and transl­ation.

Eukaryotic Cell Structure

Plants, animals, fungi, slime moulds, protozoa, and algae are all eukary­otic.

The plasma membrane resembles that of prokar­yotes in function, with minor differ­ences in the setup. Cell walls may or may not be present.

The eukaryotic DNA is organized in one or more linear molecules, called chromo­somes, which are associated with histone proteins. All chromo­somal DNA is stored in the cell nucleus, separated from the cytoplasm by a membrane. Some eukaryotic organelles such as mitoch­ondria also contain some DNA.

Eukaryotes can move using motile cilia or flagella. Eukaryotic flagella are less complex than those of prokar­yotes.

Anatomy of a Cell

Exclusive Eukaryotic Features

Cell nucleus
A cell's inform­ation center, the cell nucleus is the most conspi­cuous organelle found in a eukaryotic cell. It houses the cell's chromo­somes, and is the place where almost all DNA replic­ation and RNA synthesis (trans­cri­ption) occur.
Mitoch­ondria and Chloro­plasts
the power genera­tors: Mitoch­ondria are self-r­epl­icating organelles that occur in various numbers, shapes, and sizes in the cytoplasm of all eukaryotic cells. Mitoch­ondria play a critical role in generating energy in the eukaryotic cell.
Endopl­asmic reticulum
is a transport network for molecules targeted for certain modifi­cations and specific destin­ations, as compared to molecules that float freely in the cytoplasm.
Lysosomes and Peroxi­somes
Lysosomes contain digestive enzymes (acid hydrol­ases). They digest excess or worn-out organe­lles, food particles, and engulfed viruses or bacteria.
the cytosk­eleton organiser: The centrosome produces the microt­ubules of a cell – a key component of the cytosk­eleton.
Vacuoles store food and waste. Some vacuoles store extra water. They are often described as liquid filled space and are surrounded by a membrane.

Eukaryotic and prokar­yotic

The ribosome is a large complex of RNA and protein molecules. They each consist of two subunits, and act as an assembly line where RNA from the nucleus is used to synthesise proteins from amino acids.

Cellular Processes

Between successive cell divisions, cells grow through the functi­oning of cellular metabo­lism. Cell metabolism is the process by which individual cells process nutrient molecules.

Metabolism has two distinct divisions: catabo­lism, in which the cell breaks down complex molecules to produce energy and reducing power, and anabolism, in which the cell uses energy and reducing power to construct complex molecules and perform other biological functions.

Complex sugars consumed by the organism can be broken down into a less chemically complex sugar molecule called glucose. Once inside the cell, glucose is broken down to make adenosine tripho­sphate (ATP), a form of energy, through two different pathways.

Cell Division

Hypert­onic, Iostonic, and Hypotonic Diagrams



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