BIO FINAL REVIEW

Mooradian 2012

Eukaryotic Cells are Larger than Prokaryotic cells

Organisms that are Eukaryotic:Every organisms that isnot bacteria

– Animals– Plants– Fungus– Protists

Organisms that are Prokaryotic:

Every bacterial cell– Eubacteria– Archeabacteria

Eukaryotic vs. Prokaryotic Cells

Eukaryotic Cells

• Large• Have chromosomes• Have membrane-

bound organelles–Nucleus–Mitochondria–Centrioles

Prokaryotic Cells

• Small• No chromosomes,

only small circle of DNA (plasmid)

• No membrane-bound organelles.

Animal

• No cell wall• No chloroplast• Small vacuoles• Has centrioles

Plant• Cell wall• Chloroplasts• Large vacuole• No centrioles

Please review the following organelles:

• Cell wall• Cell membrane• Nucleus• Mitochondria• Chloroplast• vacuole

Cell Wall• A rigid structure found on the outside of plant,

fungal and bacterial cells• Permeable – allows most substances to enter

freely• Composed of cellulose and protein• Located OUTSIDE of the cell membrane• Structure relates to function:– The rigid structure of the cell wall provides support

and structure for the organisms

Cell Membrane• Surrounds ALL cells• Semi-permeable – only allows certain

substances to pass through• Contains proteins that help to pass materials

through.• “Phospholipid bilayer”• Flexible and “fluid”

Nucleus• Membrane-bound organelle

• Found only in Eukaryotes

• Controls the cell functions and processes

• Contains DNA that directs the formation of necessary proteins. (genetic blueprint)

MITOCHONDRIA• “Powerhouse” of the cell• Converts food into energy (ATP)• Inner and outer membrane• Has it’s own DNA (endosymbiotic theory)• Found in Eukaryotes only• Found in both plants and animals

CHLOROPLASTS• Converts sunlight, water and carbon dioxide to sugar

and oxygen through photosynthesis– Has chlorophyll – pigment that captures the sun’s light.

• Inner and outer membrane• Found in Eukaryotes only• Found only in plants (producers/autotrophs)

Biogeochemical Cycles• Water Cycle (hydrological)– How water is transferred from the atmosphere to earth,

through organisms and back to the atmosphere• Carbon Cycle– How carbon dioxide and oxygen are cycled from the

atmosphere through organisms and back to the atmosphere.

• Nitrogen Cycle– How organisms convert (fix) unusable nitrogen in the

atmosphere to usable nitrogen to make proteins

Carbon Cycle

TERMS• Respiration• Photosynthesis• Combustion• Decomposition• Fossil Fuels

FOSSIL FUELS• Fossil fuels are made from organisms that died

millions of years ago and were buried• They are “non-renewable”, meaning there is a

limited supply.• Examples:– Coal, oil and gas(fossil fuels)-nuclear power**sometimes ConsideredRenewable, but we WILL run out of uranium

Renewable Resources

• Resources that have unlimited supply.• Often considered “green”• Often do not release harmful pollutants

and/or carbon dioxide• Examples:– Wind, solar, geothermal, hydroelectric (water)

Acid Rain• Acid rain is formed when nitric and sulfuric acid is released into the atmosphere

from coal-burning power plants.• An increase in the acidity of an ecosystem

causes many organisms to die• Ecosystems downwind from factories experiencethe most acid rain

Global Warming

• When fossil fuels are burned to make energy, they release CO2 and other harmful substances into the atmosphere.

• High levels of CO2 have been linked to increasing temperatures on Earth (Greenhouse Effect)

• Increasing temperatures on Earth will lead to climate changes (Global Warming)

Destroying the Ozone Layer• The ozone layer is a part of our atmosphere

that protects us from carcinogenic (cancer causing) UV rays from the sun.

• Chloroflourocarbons (CFCs) – found in aerosol can products and coolants

• CFCs attack and destroy ozone• Most countries have banned CFCs

PHOTOSYNTHESISAND

CELLULAR RESPIRATION

PHOTOSYNTHESIS

6CO2 + 6H20 C6H12O6 + 6O2

reactants products Carbon dioxide + water glucose + oxygen

Cellular Respiration – releases the energy in food and turn it into a form

that can be used for the activities of life

C6H1206 + 602 6CO2 + 6H2O + 36 ATP

ORSugar (glucose) + oxygen carbon dioxide + water + energy

Identify products and reactants*Reactants ALWAYS to the LEFT of the Arrow

Know what are the REACTANTS of

Photosynthesis (Sunlight, Water,

Carbon Dioxide) and the PRODUCTS

(Oxygen and Glucose), the

Simplified REACTANTS of

Cellular Respiration (Oxygen, Glucose) and the PRODUCTS(Energy-ATP, Carbon

Dioxide and Water)

Genetics• Organisms are a product of the genes they

receive from their parents. These genes make proteins, such as pigments, that make individuals who they are/what they look like – to an extent…..

Structure of DNA

• DNA is made up of nucleotides. Each nucleotide of DNA consists of:– A sugar “deoxyribose”– A phosphate – A nitrogenous base:• Adenine Thymine• Cytosine Guanine

‘A’ binds with ‘T’, ‘C’ binds with ‘G’

When nucleotides are bonded, they compose a DNA molecule

• Double-helix/spiral ladder• Sugar-phosphate “backbone”• Bases are rungs of ladder• Long sequences of bases make up genes

Number of Chromosomes

• Organisms have 2 different types of cells–Body (somatic) cells: skin, liver, brain–Sex cells (gametes): sperm and egg

• Because sperm and egg need to meet and combine their chromosomes to form a new individual, they have ½ the number of chromosomes as body cells

CHROMOSOME NUMBERS

sex cells/haploid (N) Body cells/diploid (2n)

• 23• 12• 4• 20• 10• 22

• 46• 24• 8• 40• 20• 44

In Humans Sex cells have 23 (23 from Sperm + 23 from Egg = 46)

Cells are formed by Mitosis and Meiosis• Mitosis is the division of a cell into body cells. (End with TWO daughter

cells, EACH with diploid # of chromosomes- 46 in humans)• Meiosis is the division of a cell into sex cells. (End with FOUR daughter

cells, EACH with HALF the # of chromosomes – haploid- 23 in humans)

Crossing Over = Genetic Variation

homologous pairs TetradTetrad, homol. pairs together

A NORMAL Process that occurs- allows for genetic variation

Chromosomes are counted on karyotypes

Normal Human Karyotype:• 46 chromosomes– 23 pairs

• 44 autosomes– 22 pairs

• 2 sex chromosomes– 1 pair• XX = female• XY = male

Down’s Syndrome Karyotype“Trisomomy 21”

**THREE Chromosomes at 21**

Genetics Terminology

• Genes – segment of DNA that codes for a trait

• Alleles – different versions of a gene:–Allele for brown eyes, allele for blue eyes• Both genes code for hair color, but have

different versions

• Letters are used to indicate alleles. Ex. B, b

Genetics Terminology, cont.• Dominant – The allele that is expressed (B)• Recessive – The allele that is not expressed

when paired with a dominant. Only expressed when paired with another recessive gene (b)

Ex) Heterozygous brown mouse (Bb) 1. How do you know brown is the dominant

phenotype? 2. How do you know to use the letter “B” or “b”

Genetics Terminology, cont.

• Homozygous – an individual who has the same alleles for a trait. (CC or cc)– Ex. 2 genes for cystic fibrosis

• Heterozygous – an individual who has different alleles for a trait. (Cc)– Ex. One gene for cystic fibrosis, one for normal

Genetics Terminology, cont.

• Phenotype: the physical traits of an organism– Ex: brown eyes

• Genotype: the genes that an individual has– Ex: Bb, BB = Brown eyes bb = Blue eyes

*The phenotype is determined by the genotype

Carriers• When discussing diseases, heterozygous individuals are

often called “Carriers” • Carries means that an individual carries a gene that is

not shown (expressed).• An “affected” individual has the disease in question. If

it is a recessive disease, their genotype will be homozygous recessive.

• Ex. People who are carriers for cystic fibrosis, have the gene for the disease, but do not have the disease (because it is recessive)

• Ex. Cross a normal individual (NN) with a person who is a carrier (Nn) for cystic fibrosis.– Normal is dominant (N)

Cross two carriers of Tay-Sachs disease

Phenotype:

_______ % Unaffected

_______ % Affected

Genotype:

________% Hom. Dom

________% Carrier (HET)

________% Hom Rec.

Generations• Parent generation = P• Offspring of P generation = F1• Offspring of F1 generation = F2

Cross a homozygous dominant purple flowerwith a homozygous recessive white flower. Givethe F1 genotype and phenotype percents.

Purple = PP, white = pp

Practice Crosses1. Cross Bb x Bb (black and white)2. Give the F2 of BB x bb (black and white)3. Cross a heterozygous black mouse with a

white mouse. Give the F14. Cross a homozygous dominant black mouse

with a white mouse. Give the F2.5. Cross two carriers (Nn) for cystic fibrosis6. Cross a normal/unaffected (NN) with an

affected (nn) for cystic fibrosis.7. Cross a normal/unaffected with a carrier for

tay-sachs

Phenotype:

_______ % ___________

_______ % ___________

Genotype:

________% Hom. Dom.

________% Het.

________% Hom. Rec.

Pedigree Charts• Pedigree charts follow a genetic mutation/disease

through several generations of a family.• You can determine what chance offspring has of

having a disease based on family history and Punnett Square.

• The main diseases that are tracked this way are:– Tay-sachs– Huntingtons– Colorblindness– Hemophilia– Cystic fibrosis

Basic Symbols

How to read a pedigreePHENOTYPESClear = unaffectedShaded = affectedGENOTYPESNot usually indicated,

but often can be determined by the phenotypes

Pedigree:recessivegeneticdisorder

RULES:1. An individual that is affected may have 2 unaffected parents

2. All of the children of two affected parents will have the trait.

Pedigree:DominantInheritance

RULES:1. Every affected individual has at least one affected parent2. Affected mating with unaffected have a 50% chance of passing the trait3. 2 affected individuals can have unaffected children

#1 – sickle-cell

EVOLUTION BY MEANS OF NATURAL SELECTION

5 Principles

1. Variation• All species have variations• Variation is the raw material for

natural selection

Ex: Variations in giraffes

2. Struggle for Existence

• Organisms produce more offspring than can survive.

• The environment produces struggles organisms must surpass to

survive

3. Only some survive to reproduce

• Some are better able to survive and reproduce (pass on their genes)

4. Natural selection results in genetic change

• Each generation contains an increased proportion of individuals with traits that promote survival and reproduction.

• What are some alleles that a successful giraffe might have?

• Neck length• Leg length

5. Species adapt to their environment• Selection makes a population better suited to

it’s environment.• The environment determines the direction of genetic change.

Evidence of Evolution

• Fossils– Bones, casts, footprints, amber, ice

• Homologous structures• Comparative embryology• Vestigial structures• Biochemical (DNA and amino acids)

Fossils

• Fossils are often found in sedimentary rock, which is formed from layers of silt and sand covering dead organisms.

• The oldest are found on the lowest layers, youngest in the upper layers

Fossils in Amber(Hardened Tree Sap)

Homologous Structures(Comparative Anatomy)

Similar structure and anatomical position

(but not necessarily the same function) in

different organisms suggesting a common

ancestry or evolutionary origin

(e.g. wings of bats and arms of humans are homologous).

Comparative Embryologythe more closely related any two species are,

the more similar their development

Vestigial Structuresstructures or organs that seem

to serve no useful function

Organisms having vestigial structures probably share a common ancestry with organisms in which the homologous

structure is functional

Biochemical/DNA Evidence

• The closer the DNA sequences of 2 organisms are, the more closely related they are.–Ex. Humans and chimps have DNA

that is 99% identical

Bacteria Facts• Prokaryotic– Small, no nucleus, kingdoms Archeabacteria and

Eubacteria• Beneficial and harmful– Cause disease– Make food– Important for digestion

• Bacterial infections can be treated with antibiotics and prevented with vaccines

Bacteria vs Virus

How Bacteria Affect Humans• Decompsers – break down material• Nitrogen Fixation – fix nitrogen for plants• Food – yogurt, olives, pickles• Drugs - insulin• Cause disease – pathogen = disease causing

agentExamples of bacterial diseases: • TB, meningitis, strep throat, bubonic plague, anthrax,

cholera, Lyme Disease

• Cause illness – botulism, salmonella, E. Coli

Viruses – microscopic particles that invade cells.

• Not a cell/not living– *ANTIBIOTICS CANNOT TREAT VIRUSES

• Vaccination provides protection against viruses

• Examples of viral diseases: Hepatitis, smallpox, Ebola, cold, flu, HIV

*Bacterial Resistance• 1. When strong bacteria survive doses of antibiotics. • 2. The strong bacteria survive and pass this strength

(immunity) on to their offspring• 3. Eventually all bacteria have a resistance to an

antibiotic and a stronger one must be used

Controlling Bacterial Diseases• Antibiotics (penicillin) and vaccination (tetanus)• Sanitation• Cooking/Refrigeration

Controlling Diseases• Sanitation and Hygiene– Washing– Filtering or boiling water– Chlorine

• Antiviral drugs– Can shorten the life span of a viral infection

• Vaccines: both Bacterial and Viral• Antibiotics• Used to kill bacteria that have caused (or could

cause) infection. Can be preventive.***Can and are developing resistance! Ex) MRSA

TAXONOMY--the branch of science that classifies and names living things.

How are Living things classified?

• physical structure (how they look)• evolutionary relationships • embryonic similarities (embryos)• genetic similarities (DNA)• biochemical similarities

KNOW THE

ORDER

OF THE

CLASSIFICATION

SYSTEM

GOES FROM

GENERAL

(KINGDOM) TO

MORE SPECIFIC

(SPECIES)

HOW ARE LIVING THINGS NAMED?

NOMENCLATURE--a system for naming things

BINOMIAL NOMENCLATURE a two word naming system used in Biology to name organisms.Carolus Linnaeus devised this in the 1800's using these two subgroups for the name(uses Latin- a ‘universal’ language)

GENUS & SPECIES(more general) (more specific)* Humans are known as Homo sapiens

Important Terms

• Producer/Autotroph (Auto = self, troph = feeder)– organisms that produce their own food directly from the sun’s

energy.• Take in energy from their surroundings and and store it in

complex molecules such as carbohydrates.• Use the process of photosynthesis to make complex

molecules

Important Terms• Consumers/Heterotrophs (hetero = other)– Organisms that obtain energy by consuming other

organisms. Feed on others (hetero-troph)• Feed on producers and other consumers• Can be: – herbivores– carnivores – omnivores – decomposers

MONERA• Only kingdom composed of prokaryotic organisms• Single cell (no multicellular forms)• Have a cell wall• No membrane-bound organelles • Autotrophic or Heterotrophic

(ex- Bacteria, some algae)

The Archaebacteria, the most ancient of this kingdom, are so differentthat they may belong to a separate kingdom.

Other groups of Monera include the cyanobacteria (autotrophic) and eubacteria (heterotrophic).

PROTISTA• The most ancient eukaryotic kingdom• Eukaryotic • heterotrophic, autotrophic, or both• Perhaps they are best defined as

eukaryotes that are NOT fungi, animals, or plants.

(Ex- Amoeba, Paramecium, Euglena)Euglena- both autotrophic and

heterotrophic(have chloroplasts)

FUNGI• Eukaryotic, heterotrophic, usually

multicellular group having multinucleated cells enclosed in cells with cell walls.

• Decomposers: They obtain their energy by decomposing dead and dying organisms and absorbing their nutrients from those organisms.

• Some fungi also cause disease (yeast infections, rusts, and smuts), while others are useful in baking, brewing, as foods, drugs and sources for antibiotics.(Ex- mushrooms, yeast, molds)

PLANTAE

• Plants are immobile, multicellular eukaryotes that produce their food by photosynthesis (autotrophic)and have cell walls.

• Plants are important sources of oxygen, food, and clothing/construction materials, as well as pigments, spices, dyes, and drugs.

ANIMALIA• Animals are multicellular, heterotrophic

eukaryotes that are capable of mobility at some stage during their lives, and that have cells lacking cell walls.

ANIMAL KINGDOMReview your class notes on the nine main animal phyla, concentrating on the main characteristics of the digestive systems (if any), segmentation (if any) and exoskeleton (if any) of these 5 invertebrate phyla:

• Porifera (sponges)• Cnidaria (Jellyfish- stinging cells-nematocysts)• Nematodes (roundworms)• Annelids (segmented worms- earthworms, leeches)

• Arthropods (insects, spiders, crustaceans)

VOCABULARY YOU SHOULD KNOW:

• Coelomate vs Acoelomate• Radial vs Bilateral Symmetry• Sessile • Nematocyst• Exoskelteton/Chitin• Notochord• Ectotherm vs Endotherm (Cold Blooded vs Warm

Blooded)

Cold-Blooded vs Warm-Blooded” Ectotherms vs Endotherms

• ECTOTHERMS: Body temperature regulated by interactions with the environment. All invertebrates, all vertebrates except mammals and birds.

• ENDOTHERMIC: Internal temperature kept constant from homeostasis mechanisms

• The only two groups of animals that are warm blooded are the Birds and the Mammals. Need about 3-10 times more food to survive, so need to be that much better about GETTING their food.