Download The LAST LOOK Biology EOC Review Guide

The LAST LOOK Biology EOC Review Guide
The Bare Necessities you need to remember
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Organic Molecules – compounds containing carbon bonds
1. Carbohydrates (sugars) – pasta, bread, fruit; source of energy
a. Simplest is a monosaccharide or simple sugar (glucose, fructose)
b. Two monosaccharides make a disaccharide (sucrose – table sugar)
c. Chains of monosaccharides make polysaccharides (starch, cellulose,
glycogen)
2. Proteins – building blocks of amino acids; amino acids combine to form proteins
3. Lipids (fats) – do not dissolve or break apart in water; store energy from excess
food
4. Nucleic acids – information passed from one generation of cells to the next (genetic
information) is stored in nucleic acids
a. Assembled from individual units called nucleotides – each nucleotide is made
up of a 5-carbon sugar, phosphate group, and nitrogen base
b. Two most important nucleic acids are DNA and RNA – genetic info stored in
DNA is transferred by RNA (carries information from DNA to ribosomes) to direct
production of proteins.
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Cell Organelles
1. Nucleus – Control center of the cell; contains the DNA
2. Cell membrane – thin layer surrounding cell; semipermeable so that some
substances can pass through to take in nutrients and dispose of waste
3. Cytoplasm – jellylike material located between cell membrane and nucleus
4. Ribosomes – where proteins are made in the cell
5. Endoplasmic reticulum (ER) – system of membranes and sacs that act like a
highway along which molecules move from one part of the cell to another
6. Golgi apparatus – proteins move from ER to Golgi apparatus before they are
transported to different parts of the cytoplasm
7. Mitochondria – site of chemical reactions that transfer energy from organic
compounds into a substance called ATP (this molecule stores energy in its chemical
bonds); When ATP bonds are broken, they release energy and ADP is formed – the
energy is then available to meet the needs of cells
8. Lysosomes – digestive system of the cell; small spherical organelles (rare in plant
cells)
Plants only:
9. Cell wall – outer layer surrounding cell membrane; makes cell rigid and protects
10. Vacuole – fluid-filled organelle that store enzymes and wastes; can be very large
11. Plastids contain pigments – chloroplasts is a type of green plastid that absorbs the
sun’s energy so plants can make food
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Two major group of Organisms
1. Eukaryotes – organisms whose cells have a membrane-bound nucleus and
organelles; examples are animals and plants
2. Prokaryotes – organisms do not contain membrane-bound organelles; examples
are bacteria and blue-green algae
Cellular Organism Hierarchy
Cell – tissue – organ – organ system - organism
Homeostasis – ability of an organism to regulate internal conditions despite changes
to outside environment (balance); temperature, pH, metabolism
Diffusion
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Transportation in and out of cells
Movement of particles from an area of higher concentration to an area of lower
concentration
Particles move from areas where they are more crowded to areas where they are
less crowded
The most important substance to pass through the cell membrane is water. This
type of diffusion is called osmosis.
Enzymes
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Organic catalyst that controls the rate of chemical reactions within cells; enzymes
are proteins (made from amino acids)
Without enzymes many chemical reactions that occur in living things would not be
able to occur or would occur too slowly for organisms to survive
Surface of an enzyme has a distinct shape that allows it to binds with to another
enzyme – like puzzle piece or a lock and key.
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Respiration
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Aerobic Respiration – requires oxygen; cellular respiration is aerobic
Anaerobic Respiration – does not require oxygen; begins with glycolysis and
followed by fermentation
Photosynthesis
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Process by which plants produce foods in form of simple sugars and then converts
them to complex carbohydrates which store energy
Chemical reaction in which CO2 from air combines with water in the presence of
sunlight to produce organic compounds and O2
Autotrophs – organisms that produce food, such as plants
Heterotrophs – organisms that cannot produce their own food (animals)
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DNA Structure
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Made up of individual nucleotides
Each nucleotide in DNA has one of 4 possible nitrogen bases:
o A – adenine
o T – thymine
A pairs with T
o G – guanine
o C – cytosine
C pairs with G
Nucleotides from long chains and two chains twist like a spiral staircase (double
helix) to make one molecule of DNA
DNA replication
Total number of cells must increase in order for an organism to grow
Process by which a cell forms a new cell is known as cell cycle
When a cell divides an identical copy of DNA is passed alone to each new daughter
cell.
RNA
 Single strand instead of a double strand like DNA
 Has uracil (U) base instead of thymine (T)
 3 main types:
o mRNA (messenger) – carries instructions from DNA; instructions arranged in
sequences of 3 nucleotides called condons (codes for a particular amino
acid)
o tRNA (transfer) – carries amino acids to ribosomes
o rRNA (ribosomal) – part of the structure of ribosomes
Chromosomes
 A molecule of DNA can be very long – in order to fit inside the nucleus, it wraps
around proteins and becomes tightly packed into structures called chromosomes
 Every species has a certain number of chromosomes unique it its species – humans
as 46 or 23 pairs
 Each sections of a chromosome is called a gene and codes for specific trait for that
organism – each chromosome contains many genes.
 Main function of genes is to control production of proteins (proteins determine the
characteristics of an organism)
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Reproduction
Asexual – producing offspring by a single parent; offspring are genetically identical to
the parent
Ways cell divide in asexual reporduction
Binary fission – cell divides and each part receives one copy of genetic information;
used in asexual reproduction; example – bacteria and other prokaryotic cells
Eukaryotic cells division is more complex – 5 main stages:
1. Cell grows and carry out routine functions
2. Cell’s chromosomes are copied
3. Cell prepares nucleus to divide
4. Nucleus divides into two in a process called mitosis. Mitosis ensures that each new
cell receives a copy of every chromosome.
5. Once mitosis is complete, the cell divides into tow cells that are identical to the
parent cell.
Sexual – two parent cells join to form a new individual
 Sex cells (gametes) are different from other body cells
 They are haploid which means they have half the number of chromosomes present
 Use a process called meiosis that cuts the number of chromosomes in half.
 When sex cells are formed, the chromosomes are copied once and then the nucleus
divides twice.
 The resulting 4 cells have half the number of chromosomes found in a normal body
cell.
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When sex cells combine during a process known as fertilization, the resulting cell
has a complete set of chromosomes – half from each sex cell.
The offspring are diploid – means they have two copies of each chromosome
The offspring of sexual reproduction have a mix of the genetic material from both
parents and are not identical to either.
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Patterns of Inheritance
Traits
 Dominant allele is expressed in a physical characteristic. Written with an
uppercase letter. (BB – homozygous or Bb - heterozygous)
 Recessive allele is not expressed in a physical characteristic. They are
expressed when there are no dominant alleles present. Written with a lowercase
letter (bb – homozygous).
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Genotype – the alleles that an organism inherits from its parents make up the
organism’s genotype or genetic composition; examples are BB, Bb, bb
Phenotype – even though there can be 3 different genotypes, there are only 2
phenotypes – the physically displayed trait such as color.
Mendelian Genetics
Gregor Mendel – Austrian monk in mid 1800’s used pea plants to discovery many of the
things that lead to our current understanding of genetics.
Punnett Squares are diagrams used to identify possible combinations of dominant and
recessive alleles in offspring.
Pedigree is a family record that shows which members inherit a specific trait over
generations. Square boxes are male; circles are females; colored squares/circles have
the disorder and half-colored squares/circles carry the trait.
Sex-linked traits are carried on sex chromosomes (23rd pair); they usually only appear
in males – color blindness is an example.
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Genetic Technology (Biotechnology)
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Human Genome Project completed in 2003 (started in 1990) mapped the 30-40
thousand genes in human DNA.
Cloning – genetically identical organisms created from a single cell. Dolly, the
sheep is most well-known example.
Genetically Modified Foods – engineered to grow larger, faster, and more disease
resistant
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Genetic Engineering – genes or pieces of DNA are taken from one organism and
transferred to another organism; when the DNA pieces combine, they become
recombinant DNA.
Stem Cell Research – human body produces billions of new cells every day and
most have specific jobs; early in development they become specialize, such as
blood, muscle, or brain cells; some cells are not specialized and can develop into a
variety of cells – these are called stem cells. Researchers want to use these cells to
replace cell damage from injury or disease. Two sources of stem cells – embryonic
or adult tissue.
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Evolution – process of change over time
 Species – group of organisms that can interbreed to produce fertile offspring.
 Variations – differences in characteristics that occur among in organisms
 Adaptation – trait that improves and organism’s chance for survival and
reproduction
 Mutations – change that occurs in DNA sequence; usually an error
Natural selection – theory proposed by Charles Darwin that states that organisms best
suited to their environments as a result of favorable characteristics survive and
reproduce.
Evidence for evolution
Fossils – preserved remains of organisms
Comparative morphology – structures of living things are compared to understand the
development and relationship among species
 Analogous structures – serve same purpose in different species but evolved
independently – structures did not evolve from the same structures in a common
ancestor
 Homologous structures – similar body parts found in different species
Embryology – study of early stages of life, before birth. Many organisms are similar in
appearance and have common features as embryos but vary significantly as adults
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Classification – systematic grouping of organisms based on common
characteristics.
Taxonomy – science of identifying, classifying, and naming living things
Carolus Linnaeus Swedish, 700’s) developed the hierarchical system used today.
1. Domain
5. Order
2. Kingdom
6. Family
3. Phylum
7. Genus
4. Class
8. Species – smallest
Organisms are universally named using genus and species (Latin is the language used)
Dichotomous Key uses several pairs of statements. Based on observation, you
choose a statement and proceed to the next pair of observations or the name of the
organism
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Protists
1. Protozoans: animal-like
 Zooflagellates: swim with a flagellum – long projection that looks like a whip
 Sarcodines: move using projections from the cytoplasm call pseudopods
(example: amoebas)
 Ciliates: have short hair-like projections called cilia (used for movement and
feeding)
1. Algae: plant-like; contain chlorophyll and conduct photosynthesis; can move
around like animals (ex. Diatoms, green, red, brown algae, euglena,
dinoflagellates)
2. Fungus-like protest: slime and water molds
Plants
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All are multicellular autotrophs
Cells are eukaryotic
Have chloroplasts and cell walls
1. Nonvascular – lack vascular tissue; examples – mosses, liverworts, hornworts
2. Vascular – have system of tubes that transport food, water, and minerals in a plant;
vascular tissue provides strength and stability enabling vascular plants to grow tall;
examples are palm trees, rose bushes, bamboo
Life cycle of plants
1. Sporophyte – plant has a complete set of chromosomes and is diploid; produces
spores (tiny cells that grow into new organisms); spores develop into . . .
2. Gametophyte – haploid (has only ½ number of chromosomes as sporophyte); plant
produces gametes (egg and sperm cells)
3. Sperm cell and egg cell join during fertilization to form a zygote (fertilized egg) –
zygote develops into a sporophyte and cell begins again.
Seed Plants
1. Gymnosperms
 produces cones: both male – produce pollen which become sperm cells; and
female gametophyte is produces in ovule
 usually have needle-like leaves (reduce water loss)
 examples are pine trees
 during fertilization, pollen falls from male cones onto a female cone; wind usually
carries the fertilized seed to location suitable for growth
2. Angiosperms
 Produces flowers and has seeds enclosed in fruits
 Reproductive structure is a flower
 Male reproductive part is the stamen and female part is called pistil
 Pollen is carried by wind or animals
 Once fertilized, the ovary becomes the fruit
Plant Adaptations
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Roots- anchors plat in ground to absorb water and nutrients from soil
Stems- support plant and transport material
Leaves- site of photosynthesis
Animal Adaptations
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Predator adaptations increase animal’s chances of catching prey (food); the speed
of a lion is an example.
Prey adaption help an animal keep from being killed.
o Mimicry is an adaptation that helps animals look more dangerous to other
animals.
o Camouflage – animals blend in with their surroundings to hide from predators
Coevolution: process in which 2 species evolve in response to change in each other;
likely to occur when 2 species have a close relationship and are dependent on each
other; example – plants and their pollinators
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Pathogens
Robert Koch (German; 1880’s) developed a theory that diseases are caused by a
pathogen – organism that causes a disease
Bacteria
 Unicellular
 Some are helpful (live in intestines and help with digestion; make food – yogurt,
bread)
 Others cause strep throat, ear infections, tuberculosis, etc
 Can damage cells and tissue or release toxins (poisons)
Viruses
 Genetic material surrounded by a protein shell
 Smaller than bacteria
 Have some features of living things, but cannot survive without a host
 Can only reproduce inside living cells
 Examples – chicken pox, rabies, measles
Fungi
 Eukaryotic heterotrophs
 Feed on dead or decaying organic matter
 Grow best in dark, moist climates
 Examples – ringworm, athlete’s foot
Protist
 Cause malaria, African sleeping sickness
Life Functions in Mammals
1. Feeding
2. Respiration and circulation
3. Homeostasis
4. Movement
5. Nervous System
6. Reproduction – placental (mothers carry young in uterus until they develop
enough to live outside her body; marsupials (have a short development inside
mother and then continue development in pouch outside the mother);
monotremes – lay eggs
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Factors Affecting Health and Disease
Noncommunicable disease – cannot be transmitted from one person to another
Communicable disease – can be spread from one person to another; contagious if it
spreads quickly and easily from one person to the next.
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Genetics – some disease can be passed from one generation to another
(noncommunicable); examples are hemophilia, cystic fibrosis
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Parasites – microorganisms; live on or in another organism and feeds off it;
examples of human diseases caused by parasites – malaria, roundworm
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Toxins – poisonous substance; botulism (food poisoning) and fungi
Immune Response – 3 lines of defense
 Skin – acts as a barrier
 Injured cells release chemicals that increase blood flow to an invaded region such as
cut or scrape – the blood bring white blood cells that attack pathogens
 Attacking specific pathogens with T and B cells
Nutrition
 Vitamins – substance essential to body in small amounts; obtained naturally from
plant and animal foods; required for normal growth and activity; A, D, E, K, B, & C
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Minerals – nutrients not made by living things; obtain by eating plants that have
absorbed minerals through their roots and animals that have eaten the plants;
calcium, iodine, iron, potassium
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Levels of Organization
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Ecosystem – groups of organisms living together and interacting with each other
and the environment around them; examples: desert, rainforest. Tundra,
temperature forest
Ecology – scientific study of interrelationships of organisms and their environments
Stability of ecosystem is dependent on interactions of populations (group of
individuals of the same species living in the same area) in an ecosystem
Community – interacting populations
3 kinds of Symbiosis – permanent relationship between two different types of
organisms
 Mutualism – both organisms benefit one another; example: clownfish that dwell
among the tentacles of Ritteri sea anemones. The fish protects the anemone from
anemone-eating fish, and in turn the stinging tentacles of the anemone protect the
clownfish from its predators. A special mucus on the clownfish protects it from the
stinging tentacles
 Commensalism – one organism benefits from the other; the other organism is
neither harmed nor helped; example: Crabs and Shrimps live with anemones in
tropical waters, for the purposes of protection from predation.
 Parasitism – one organism benefits and the other is harmed; example: tick feeding
on the blood of its host
Predation – A predator (animal that eats other animals) feeds on prey (an animal being
killed or eaten); predators are important to control sizes of prey populations; if predators
decrease, prey animals increase often to higher numbers than an ecosystem can
support
Practice Quiz: Examples of Symbiosis
http://www.cstephenmurray.com/onlinequizes/biology/Ecology/typesofinteractionsexamples.htm
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Factors Limiting Populations
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Abiotic factors – things in environments that are not alive; examples include light
sources, temperature, amt. of precipitation, type of soil, etc.
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Biotic factors – things in environments that are living; all organisms
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Limiting factors – environmental things that can affect size of populations; is there
enough water, food, sunlight, oxygen, etc
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Carrying Capacity – largest population that a given environment can support over a
long period of time.
Cycling Matter
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Carbon Cycle – process where carbon is taken from the air, used in photosynthesis
to make food for plants which then release oxygen and water back into the
atmosphere
Decomposers – organisms that break down the remains of dead organisms; they
return energy and nutrients to the environment; fungi and bacteria are decomposers
Combustion – fuels are burned; oxygen is consumed and carbon dioxide is
released into atmosphere
Energy Flow in Ecosystems
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Producers – organisms capable of making food; plants
Consumers – organisms that eat producers to get food
Herbivores – organisms that eat only plants
Carnivores – organisms that eat other animals
Omnivores – consumers that eat both plants and animals
Scavenger – feeds off organisms that are dead; example – turkey vulture
Decomposers – break down remains of dead organisms
Food Chains - Shows the flow of energy from producers to consumers to decomposers
Energy Pyramids
 Each step in the feeding relationship is called a trophic level
 Producers are the 1st tropic level
 2nd – secondary consumers
 Top – carnivores
 Then decomposers
 Not all energy stored in producers passes to decomposers – about 10% of the
energy goes from one tropic level to the next
Food Webs - Food chains that are interconnected
Human Impact on Environment
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Pollution
Deforestation
Population Growth
Resource depletion
Climate change
Experimental Variables
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Control Variable – the variable that does not change; compare this group to the
group being tested
Independent Variable – what is being tested
Dependent Variable – result or the change based on the independent variable
being used.