Biology Review Notes What is Biology?
Bio = life, -Logy = the study of
Biology is the study of living things and their surroundings
Organism = a living thing; anything possessing the characteristics of living things.
Characteristics of living things:
o All living things grow and develop.
o All living things reproduce.
o All living things are organized.
o All living things adjust to their surroundings.
o All living things need energy (ATP).
o All living things are made up of cells.
o All living things contain genetic material (DNA).
Reproduction = organisms making more of their own kind, making offspring.
Offspring = babies, when organisms reproduce they produce offspring
Growth = organism gets bigger
Development = organism changes shape or form. It develops new structures.
Metamorphosis = type of development where an organism makes a very big change in shape or form.
Ex: tadpole to a frog; caterpillar to a butterfly.
Environment = organism’s surroundings, both living and nonliving.
Adaptation = physical change that arises in an organism over time through the process of evolution.
Organization:
All living things are organized in the following way:
o atoms molecules cell parts cells tissues organs organ system organisms (smallest to largest)
Homeostasis:
Homeostasis = an organism remaining constant in a changing environment; maintaining a stable, internal environment
Every organism tries to regulate how much of each chemical is present in it. They try to keep the level or the amount constant or the same. TOO much or TOO little is bad!
o Ex: body temperature = 98.6; too cold or too hot is bad and that is why we sweat or shiver to maintain that 98.6
Scientific Method:
Independent variable = the part of the experiment that is changed or manipulated in the beginning (I change the IV)
Dependent variable = the part of the experiment that is different at the end; the part that is measured at the end. (DV = Data)
Constants = conditions in an experiment that are the same for every group.
Control = the group that is kept under normal conditions or that is not being tested.
Hypothesis = predication. Testable sentence. Usually in If….Then format.
Experiment = procedure done to test a hypothesis.
Quantitative data = data that can be counted or measured, numbers
Qualitative data = data gathered by observing qualities, descriptive
Biomolecules- molecules that help to make up cell parts, cells, and living things.
Organic Molecules - any molecule that contains some carbon (c). ALL of the biomolecules are organic.
The FOUR biomolecules:
Carbohydrates
o Composed of C, H, and O
o Examples include pasta, bread, and many vegetables
o Store and release quick energy o Structural support in plants
Lipids
o Composed of C, H, and O
o Building block (subunit) is glycerol and 3 fatty acids o Examples include fats, oils, waxes, and steroids o Long-term energy storage
o Major part of the cell membrane
Proteins
o Composed of C, H, O, and N
o Building block (subunit) are amino acids o Helps with muscle contraction
o Transports oxygen in blood o Examples include tuna, meat
o Carries out (speeds up) chemical reactions (enzymes)
o
Nucleic Acids
o Composed of C, H, O, N, and P
o Building block (subunit) is a nucleotide: sugar, phosphate, nitrogen base o Examples include DNA and RNA
o Stores information in cells in the form of a code
Biochemistry
Organic
o Any substance/molecule that contains Carbon
pH scale
o Scale that determines how acidic (H+) or basic (OH-) a substance is
Acid: pH of 1-7
Base: pH of 7-14
Neutral: pH of 7
Properties of Water
o Expands when freezes: Causes ice to float, forms soil by cracking rocks o Resists temperature change: keeps organisms’ environments stable
o High heat of vaporization: high energy needed to evaporate; helps body cool through sweating o Capillary action: can creep up thin tubes for movement and transport
o High surface tension: molecules stick together
Osmosis/Diffusion: movement of water (particles) in and out of a cell
o Hypotonic: higher concentration of water OUTSIDE the cell; cell will swell o Hypertonic: higher concentration of water INSIDE the cell; cell will shrink Cells
Important cell scientists:
1. Hooke: Looked at cork (dead cells), came up with term “cell.”
2. Leeuwenhoek: Invented the microscope. First to look at living cells.
3. Schleiden: studied plant cells.
4. Schwann: studied animal cells (schwann sounds like swan).
5. virchow: first to see cells divide under the microscope.
The Cell Theory:
1. all living things are made of cells. (this is why visuses are NOT living) 2. all cells come from pre-existing cells.
3. cells are the basic unit of organization.
Prokaryotic cells:
primitive, small, NO organelles or nucleus, DNA is in the cytoplasm
first cells on earth were prokaryotic
bacteria are this type of cell
Archaebacteria and Eubacteria = two prokaryotic kingdoms Eukaryotic Cells:
Advanced cells, larger than prokaryotic cells, DNA in nucleus, has organelles
Plants, animals, fungi, and protest are made of this kind of cell.
Endosymbiont Theory:
Big cell ate little cell and kept it around to do work. Little cell became an organelle.
Evidence for theory:
Mitochondria : most scientists believe that they were once aerobic bacteria.
Chloroplast : most scientists believe that they were once cyanobacteria or blue green algae.
Cell Parts:
cell membrane: semi-permeable membrane surrounding the cell; allows materials to enter and leave the cell cell wall: additional boundary of plant cells providing structural support
cytoplasm: clear, gel-like fluid inside of a cell, where important chemical reactions take place ribosomes: where proteins are made in the cell
ER: folded system of membranes for transport of materials through a cell
golgi apparatus: flattened stack of membranes for packaging and sorting proteins vacuole: storage of food and water
lysosome: digests food and old cell parts
mitochondria: produces ATP (energy) for the cell; powerhouse chloroplast:: transforms sunlight into glucose (food) in plant cells nucleus: strores DNA, control center or brain of the cell
nucleolus: region within the nucleus that produces ribosomes
cytoskeleton: internal support system; made of microfilaments and microtubules unicellular: organism made of one cell
multicellular: organism made of more than 1 cell centriole: used for cell division in animal cells flagella: long projections used for movement by cells cilia: short, hair-like structures used for movement by cells
Plant Cells:
Plant cells have chloroplasts and cell walls; animal cell do NOT
Plant cell do NOT have centrioles
Vacuoles in plant cells are HUGE for storage
Plant cells are usually rectangular or square in shape due to cell walls
Plant cells can not pinch in to divide. Instead the must construct a cell plate to divide the two new cells.
Animal Cell:
Animal cells have centrioles, plants do NOT
Animals cells do NOT have cell walls or chloroplasts
Biomolecules and Cells:
Cell membranes are made of phospholipids, which are a type of lipid.
Cell walls are made of cellulose, a polysaccharide, which is a carbohydrate.
Cytoskeleton, centrioles, and ribosomes are made up of structural proteins.
Proteins are made in the ribosomes and rough er.
Lipids are made in the smooth er.
DNA, which is a nucleic acid, is stored in the nucleus.
RNA, which is a nucleic acid, is a copy of DNA, which carries the genetic code from the nucleus to the ribosome during protein synthesis.
Cell Differentation:
This is the process where cells in multicellular organisms become specialized or different. These cells differentiate into cells that do very different jobs.
Photosynthesis
- The process in which plants use sunlight (light energy), carbon dioxide (C02), and water to make
glucose and oxygen Equation: 6C02 + 6H2O + light energy → C6H12O6 + 6O2
Photosynthesis occurs in plants, bacteria, algae
Large percentage of photosynthesis occurs in leaves
The leaf includes the epidermis, cuticle, stomate, guard cells, palisade layer, spongy layer, air spaces, veins, xylem, and phloem
Epidermis is he outside layer
Cuticle is inside the epidermis, and is the waxy coating that prevents water loss
Stomata are tiny openings on the underside
Guard cells control the opening and closing of the stomates
Palisade layer contains the chloroplasts and most of the photosynthesis in the leaf
Spongy layer is made up of loosely arranged cells.
Air spaces are in the spongy layer, and hold gases until released into the cells of the plant
Veins contain vascular tissues
Xylem moves the water up in the veins
Phloem moves the food up and down in the veins Extra:
Glucose made in photosynthesis is used as energy in respiration
Chlorophyll is the green pigment in chloroplasts
Cellular Respiration The process to convert food into energy
Occurs in the mitochondria
This energy is called ATP
ATP is a high energy molecule and stands for Adensine Triphosphate
Can be broken down into ADP
ADP is Adensine Diphosphate
Equation: H20 + ATP ↔ ADP + P
ATP in the equation is energy stored. ADP in the equation is energy released
Two types of respiration: Aerobic and Anaerobic
Aerobic respiration needs energy, occurs in the mitochondria, occurs in the presence of oxygen, and makes 34-36 ATP
Equation: C6H12O6 + 602 → 6H20 + 6CO2 + 36 ATP
Anaerobic respiration doesn't need energy, makes 2 ATP, and is also called fermentation
Two types of fermentation: Lactic Acid and Alcoholic
Lactic Acid fermentation occurs in muscles of animals
Equation: Glucose → lactic acid + 2 ATP
Alcoholic fermentation occurs in yeast
Equation: Glucose → alcohol + CO2 + 2 ATP Extra:
Photosynthesis and respiration's reactants and products are switched
DNA
DNA stands for Deoxyribonucleic Acid
The structure of DNA was discovered by Watson and Crick; they won the Nobel Prize. (Rosaline Franklin= xray picture showing the double helix)
DNA is in the shape of a double helix, which is a twisted ladder In eukaryotic cells, DNA is stored in the nucleus
Chromosomes are made up of DNA. Genes are made up of DNA. DNA carries the genetic code. In the DNA molecule, the building blocks are nucleotides. Each nucleotide is made up deoxyribose, phosphoric acid, and a nitrogen base. A nucleotide looks like:
When the building blocks are put together, the deoxyribose and the phosphoric acid make up the 2 outer backbones of the molecule:
The nitrogen bases (A,T,C,G) pair up in the middle. Adenine pairs with thymine and cytosine pairs with guanine. (AT…CG)
Each chromosome carries many genes. Each gene tells the cell how to make a protein or a piece of a protein.
Proteins are made at the ribosomes, but the DNA never leaves the nucleus so that it can stay protected.
Messenger RNA, also known as mRNA, is a copy of the gene that carries the code to the ribosomes.
The process where the mRNA is made in the nucleus is called transcription.
Messenger RNA looks like half of a DNA molecule. It used ribose instead of deoxyribose. It uses Uracil (U) instead of T.
Every 3 nitrogen bases or letters on a mRNA or DNA molecule is called a codon. Every codon codes for one amino acid.
Transfer RNA, also known as tRNA, carries amino acids to the ribosomes.
Amino acids are the building blocks of proteins. Amino acids are joined together by peptide bonds.
The process where the mRNA code is read to tell what amino acids are needed to make a protein is called translation. It is called translation because there is a switch from mRNA language to protein language.
The genes or DNA that a person has makes up the person’s genotype.
The protein that is made from the DNA code give the person the phenotype that the person has.
Calculations:
Mean = add up all the numbers and divide by how many numbers you have. (average)
Median = put the numbers in order, it is the one in the middle
Maximum = highest number
Minimum = lowest number
Range = maximum number minus the minimum Water:
Capillary action: liquid creeps up thin tubes
Water has a high heat of vaporization, takes a lot of energy to evaporate it
Surface tension: water molecules stick together, forming film on top of water
Water expands when it freezes, ice floats, lakes do NOT freeze solid
It takes a lot of energy to change the temperature of water. Oceans keep the earth warm enough for life.
Mitosis: Interphase—Mitosis—Cytokinesis (IPMAT)
Interphase: normal part of cell, DNA and organelles are copied/replicated
Prophase: DNA is wound up into chromosomes, centrioles move to opposite sides of the cell, nuclear membrane disappears, spindle fiber form.
Metaphase: chromosomes line up at the middle, spindle fibers attach to centrioles.
Anaphase: chromosomes pulled to opposite ends/sides of the cell
Telophase: chromosomes in opposite sides, nucleus reforms, cell splits
Centrioles: only in animal cells, spindle fibers come from these.
Chromosomes: made of DNA, carry genes, neatly packaged
Chromatin: DNA unpackaged or unwound
Spindle Fibers: pieces of cytoskeleton that attach to chromosomes and pull them to opposite sides of the cell in mitosis.
Centromeres: dot that holds copies of chromosomes together. Spindle fibers attach to these.
Mitosis: cell division in body cells
Cytokinesis: when the cytoplasm divides, cell actually splits
Plant cells: can’t pinch due to cell wall, they form cell plate. They also do not have centrioles.
Cells can NOT be huge/large because:
o Surface area to volume ration, not enough doors to support in and out traffic o Only one copy of DNA to share, like building a skyscraper with 1 set of blue prints o Diffusion is too slow, oxygen can not get to the middle of the cell
Cells divide for growth, reproduction, development, to replace dead or dying cells, and to repair injuries
Meiosis: (division of sex cells)
Meiosis is the cell division that is done to make gametes
Gametes are the sperm, egg, or pollen
Gametes only have 1 copy of each gene and 1 copy of each chromosome
When gametes are combined they make a zygote (a 1 celled embryo)
Zygotes have 2 copies of each gene and chromosome. They get 1 gene from mom and one from dad.
Haploid Cell: a cell with 1 copy of each gene or chromosome
Diploid Cell: a cell with 2 copies of each gene or chromosome
Tetraploid cell: a cell with 4 copies of each gene or chromosome
X chromosome= female chromosome, Y chromosome = male chromosome
XX = female organism, XY = male organism
Humans have 23 pairs of chromosomes in each cell. This means that they have 46 chromosomes total in each cell.
Genetics:
The father of genetics is Gregor Medel; monk and scientist
Mendel’s 1 law:
o 2 genes for every trait
o 1 gene from mom and 1 gene from dad
o dominant beats recessive
Genotype: letter or genes you have for a trait (ex: TT, Tt, tt)
Phenotype: how genes make you look (ex: normal height or dwarf)
Homozygous: has 2 sets of the same genes for a trait (TT or tt)
Heterozygous: has 2 different genes for a trait (Tt)
Alleles: different forms of the gene (ex: T or t)
Sex-linked Traits: gene on X chromosome, show it as exponent o Female has 2 and male has 1
Monohybrid Cross: punnett square looking at 1 trait at a time
Dihybrid Cross: punnett square looking at 2 genes at a time
Dominant: big letters, beats recessive
Recessive: small letters, weaker than dominant, can be masked
Pedigree Rules:
o Circle is girl, square is boy
o Shaded in means two little letters (dd)
o Not shaded, at least 1 big letter (D_), figure out second letter at parents and kids Classification:
6 Kingdoms:
1. Archaebacteria: lives in extreme environment, extremophile bacteria, like high salt, acid, temperatures; prokaryotic cells
2. Eubacteria: normal bacteria, strep throat, E. coli; prokaryotic cells
3. Protista: usually unicellular or microscopic, eukaryotic cells; algae (plant like), protozoa (animal- like), slime molds (fungus like)
4. Fungi: molds, fungus, athletes foot, mushrooms, decomposer, or parasite
5. Plants: green, chloroplasts, photosynthesis, producer, eukaryotic cells, multicellular 6. Animals: move, need oxygen, multicellular, eukaryotic cells
7 part name: kingdom, phylum, class, order, family, genus, species o king phillip came over for good spaghetti
3 Domains:
o domain Archaebacteria: includes kingdom archaebacteria o domain Eubacteria: includes kingdom eubacteria
o domain Eukaria (or eukaryotes): includes kingdoms protest, fungi, animals, and plants
Scientific Name: Genus species
Binomial Nomenclature: say every animal has a 2 part name: genus species
Linnaeus is the father of taxonomy
Taxonomy: classification of organisms into groups by similarities in structure, DNA, protein, behavior, or development
Remember in a dichotomas key ALWAYS start at number 1 Cell Energy:
Photosynthesis:
o Happens in plants in chloroplast
o Chorophyll in plants catches sunlight energy and uses this energy to make glucose sugar o Plants need carbon dioxide and water to do photosynthesis
o 6 CO2 + 6 H2O + sunlight → C6H12O6 +6O2
Cell Respiration:
o happens in mitochondria. Breaks down glucose sugar to make energy or ATP.
o Mitochondria need oxygen and glucose to do respiration o C6H12O6 + 6O2 → 6CO2 + 6H2O + 36 ATP
Ecology Ecosystems
• Collection of abiotic (nonlivng) and biotic (living) factors in an area
• Together they influence growth, survival, and productivity of an organism
• Symbiotic Relationships
• Relationship between two organisms in which one benefits
• Types:
– Mutualism (+,+) – Parasitism (+,-) – Commensalism (+, o)
• Predation
• Predator eats prey
• Evolve in response to one another
• Carrying Capacity - Maximum number of individuals that an ecosystem can support
• Limiting factors:
– Food availability – Competition – Disease – Predation
– Natural Disasters
• Carbon Cycle
• Trophic Levels
• Steps in a food chain/web
• Energy passes from one organism to another
• About 10% of the energy at one level passes to the next
• Human Population
• Growth= birth rate-death rate
• Human Impacts
• Positive
• Reforestation
• Cover Cropping
• Recycling
• Sustainable practice
• Negative
• Acid Rain
• Deforestation
• Habitat Destruction
• Invasive Species
• Ozone depletion from the release of CFCs
• Global Warming
• Increase in the average temperature of the earth
• Caused by the release of too much CO2 into the atmosphere which amplifies the greenhouse effect
• Burning of fossil fuels, volcanic eruptions
• Bioaccumulation
• An increase in environmental toxins at higher tropic levels
• Ex. DDT and birds of prey Animal Behavior
• Innate Behavior
• Behaviors an animal is born with
• Includes suckling, migration, hibernation
• Ex. weaving of spider webs
• Learned Behavior
• Behavior an animal acquires during its lifetime
• Includes
– Habituation – Conditioning – Trial and error
• Social Behavior
• Communication between individuals of the same species
• Can be courtship, territorial or chemical (pheromones) Evolution
• Origin of Life
• Abiotic earth LACKED Oxygen
• Early organims anaerobic prokaryotes
• Endosymbiotic Theory
• Eukaryotic cells evolved from prokaryotes
• Early prokaryotes engulfed other prokaryotes and developed symbiotic relationships
• Evidence includes mitochondria and chloroplast have prokaryotic type DNA
• Abiogenesis
• Living from non-living or spontaneous generation
• Disproved by Redi and Pasteur’s experiments
• Biogenesis
• Living from Living
• Natural Selection
• Theory of Evolution
• Fit organisms survive, reproduce, and pass on traits Requirements:
• Variation
• Competition
• Adaptations
• Trait that increases survival
• For Example,
– Beaks that make it easier to eat insects – Bright flowers to attract pollinators
– Vascular tissue in plants to adapt to life on land
• Evidence for Evolution
• Fossil Record
• Biochemical Similarities
• Shared anatomical structures
• Speciation
• Evolution of a new species
• must be isolation between populations
• Antibiotic and Pesticide Resistance
• Populations will eventually become resistant to pesticides and antibiotics with overuse
• Coevolution
• Two organisms evolve in response to each other