Biology 1 Honors End-of-Year Review Notes

Experimental Design

Steps: Question/Observation → Hypothesis → Experiment → Data Analysis → Conclusion

Independent Variable (IV)

Manipulated by scientist (x-axis)

Dependent Variable (DV)

Measured, changes in response to IV (y-axis)

Control Group

Comparison for results

Biotic

Living or once-living

Abiotic

Non-living (e.g., rocks, weather)

Limiting factors

Limit population growth

Density-dependent factors

Worse with higher population density (e.g., disease)

Density-independent factors

Regardless of population density (e.g., natural disasters)

Exponential growth

Rapid, unchecked growth

Logistic growth

Growth that levels off at carrying capacity

Carrying capacity

Max individuals an ecosystem can support

Predator/Prey

One eats the other

Mutualism

Both benefit

Commensalism

One benefits, other unaffected

Parasitism

One benefits, other harmed

Primary Succession

Ecosystem from scratch (e.g., rock broken down by lichens)

Secondary Succession

Ecosystem recovers from damage (e.g., after a fire)

Greenhouse Effect

CO2, methane trap heat; higher CO2 = warmer temperatures

Human Impacts on Biodiversity

Deforestation, pollution, etc.

Carbohydrates

Monosaccharides, fast energy, C, H, O

Lipids (Fats)

Glycerol & fatty acids, stored energy, C, H, O, P

Proteins

Amino acids, structure/enzymes/transport, C, H, O, N, S

Nucleic Acids

Nucleotides, genetic code, C, H, O, N, P

Carbon Cycle

Photosynthesis (absorbs CO2), cellular respiration/decomposition/combustion (release CO2)

Photosynthesis (Word Equation)

Water + Carbon dioxide + Sunlight → Oxygen + Glucose

Photosynthesis (Chemical Equation)

H2O + CO2 + \text{solar energy} → O2 + C6H{12}O6

Light-Dependent Reaction

Reactants: H2O; Products: O2, ATP, NADPH

Calvin Cycle

Reactants: CO2, ATP, NADPH; Products: C6H12O6

Aerobic Cellular Respiration (Word Equation)

Oxygen + Glucose → Water + Carbon dioxide + Energy

Aerobic Cellular Respiration (Chemical Equation)

O2 + C6H{12}O6 → H2O + CO2 + ATP

Glycolysis

Reactants: C6H12O6; Products: Pyruvate, ATP, NADH

Krebs Cycle

Reactants: Pyruvate; Products: CO2, ATP, NADH, FADH2

Electron Transport Chain

Reactants: NADH, FADH2, O; Products: ATP, H2O

Alcohol Fermentation

Glucose → Alcohol + Carbon dioxide + ATP (Yeast)

Lactic Acid Fermentation

Glucose → Lactic Acid + ATP (Bacteria, muscle cells)

Cell Cycle

Interphase (G1, S, G2), Prophase, Metaphase, Anaphase, Telophase, Mitosis, Cytokinesis

Mitosis

Produces genetically identical cells

Mitosis (Plants)

Cell plate forms cell wall

Mitosis (Animals)

Cleavage furrow

Mitosis Stages Order

Prophase, Metaphase, Anaphase, Telophase

Checkpoints

Pause in cell cycle to check for issues

Ignoring Checkpoints

May form a tumor

Tumors (Malignant)

Aggressive, metastasize

Tumors (Benign)

Less aggressive, don't spread

DNA Replication Error

Apoptosis (cell death) may occur

Stem Cells

Differentiate to form specialized cells

Differentiation

Cell becomes specialized

DNA vs RNA

RNA is single-stranded, DNA is double-stranded

DNA → Genes → Chromosomes

DNA contains genes, DNA wrapped into chromosomes

Central Dogma (Protein Synthesis)

DNA → RNA → Protein

Transcription

DNA to RNA

Translation

RNA to Amino Acid Sequence

Nucleus

Contains DNA

Ribosomes

Protein synthesis site

Rough ER

Contains ribosomes

Golgi Apparatus

Modifies and packages proteins

Vesicles

Transport proteins

Meiosis

Daughter cells differ from parent cell due to crossing over and independent assortment.

Random Fertilization

Unique gene combination

Crossing Over

Homologous chromosomes exchange parts

Independent Assortment

Alleles separate independently

Mutation

Change in DNA

Incomplete Dominance

Blended phenotypes

Codominance

Both phenotypes show

Multiple Alleles

Three or more alleles for a trait

Sex-Linked

Traits on sex (X) chromosome

Natural Selection

Overproduction, Variation, Adaptation, Descent with Modification

Survival of the Fittest

Beneficial traits survive and reproduce more

Evolution Types (Divergent)

From common ancestor

Evolution Types (Convergent)

Similar environment, common trait

Coevolution

Populations evolve in response to each other

Diversity

Increases survival chances

Evidence for Evolution

Anatomy: Homologous structures, common ancestor; Embryology: Similar embryos; Biochemistry: Similar DNA; Paleontology: Similar fossils

Structures (Homologous)

Similar, common ancestor

Structures (Analogous)

Similar environment, not closely related