Biology Quiz: Key Concepts

Atoms and Elements

• Protons determine the element, neutrons increase mass, and electrons control bonding.
• Elements are composed of atoms.
• Atoms are the smallest unit of an element.

Solutions and Enzymes

• Water is the solvent that dissolves salt (solute).
• Pepsin, functioning best in acidic conditions, has the greatest rate change with minimal pH adjustment .

Carbon and Molecules

• Carbon's ability to form four bonds allows for complex molecules.
• Carbohydrates: Monomer - Monosaccharides; Polymer - Polysaccharides
• Proteins: Monomer - Amino acids; Polymer - Polypeptides
• Lipids: Monomer - Fatty acids & glycerol; Polymer - Triglycerides
• Nucleic Acids: Monomer - Nucleotides; Polymer - DNA/RNA

Population Dynamics

• Density-dependent factors (disease, competition) affect large populations.

• Density-independent factors (weather, disasters) affect all populations.

• Disease in bats is density-dependent, spreading more in crowded areas.

• Population increase may be due to warm weather or abundant food.

• Population decline may occur due to predators or pesticides.

Ecological Interactions

• A food web shows energy flow within an ecosystem.
• Producers make food, consumers eat others, and decomposers break down waste.
• If foxes die, their prey populations may increase, potentially leading to unbalanced competition.

Symbiosis and Niches

• Mutualism benefits both organisms (bees & flowers).
• Parasitism benefits one organism, harms the other (fleas on dogs).
• Niche: An organism's role in an ecosystem (diet, habitat).
• Habitat: The physical location of an organism.

Succession and Ecosystem Changes

• Primary succession starts on bare rock (volcanic eruption).
• Secondary succession starts with soil after a disturbance (forest fire).
• Secondary succession occurs when soil is present.

Cell Transport and Homeostasis

• Osmosis: Water movement across a membrane.
• Hypotonic: Water enters, cell swells.
• Hypertonic: Water leaves, cell shrinks.
• Isotonic: No change.
• The cell membrane regulates what enters and leaves the cell to maintain homeostasis.

Cell Division and Energy

• Mitosis creates identical cells for growth/repair.
• Mitosis phases: Prophase, Metaphase, Anaphase, Telophase (PMAT).
• Cellular respiration breaks down food to produce ATP.
• Photosynthesis uses sunlight to create food.
• Cellular respiration and photosynthesis are opposing processes.

Genetics and Heredity

• DNA replicates before cell division to preserve genetic information.
• Dominant alleles (A) express themselves when present.
• Recessive alleles (a) express themselves only when two copies are present (aa).

Natural Selection and Evolution

• Natural selection components: Variation, competition, survival of the fittest, reproduction.
• Beak size changes in bird populations based on survival for best food acquisition and passing traits.

Genetic Information and Protein Synthesis

• RNA's role in protein synthesis: mRNA carries the code, tRNA brings amino acids, and rRNA builds proteins.
• Transcription: DNA to mRNA (nucleus).
• Translation: mRNA to protein (ribosome).

Taxonomy

• Taxonomy classifies organisms to reveal relationships.

Biological Molecules and Functions

• Proteins perform many functions including building muscles, catalyzing reactions (enzymes), transport, and defense.

Ecological Factors

• Nutrient cycles support ecosystem functioning by recycling nutrients (carbon, nitrogen).
• Population balance depends on density, distribution, and growth rate.

Environmental Impact

• Limiting factor: Resource or condition restricting population size (e.g., food, space).
• Density-dependent factors affect populations based on size (disease).
• Density-independent factors affect all populations equally (disasters).

Biogeochemical Cycles

• Decomposers recycle nutrients back into the ecosystem by breaking down dead matter.
• Carbon moves through ecosystems via photosynthesis absorbing CO₂, respiration releasing it, and decomposers recycling it.

Ecosystem Stability and Human Impact

• Biodiversity increases ecosystem stability and resilience.
• Human impact on carbon cycle: Burning fossil fuels increases atmospheric CO₂ and contributes to climate change.

Population Growth and Carrying Capacity

• Exponential growth: Rapid population increase without limits.
• Logistic growth: Population growth slows with limited resources, reaching carrying capacity.
• Exceeding carrying capacity triggers resource depletion, competition, disease, and population decline.

Water Cycle and Climate

• The water cycle involves evaporation, condensation, precipitation, and runoff.
• Oceans influence climate by storing and distributing heat.

Ecosystem Interactions

• Competition occurs when organisms vie for the same resources, impacting population size.
• Invasive species interfere with ecosystems by outcompeting native species.

Genetic Engineering and Biotechnology

• Genetic engineering involves altering an organism's DNA for specific traits.
• GMOs (Genetically Modified Organisms) are used to enhance crop traits, disease resistance, and food production.

Cell Organelles and Their Functions

• Mitochondria produce energy (ATP) through cellular respiration.
• Nucleus controls the cell and houses the genetic material (DNA).

Photosynthesis and Cellular Respiration

• Photosynthesis equation: CO₂ + H₂O + sunlight → O₂ + glucose
• Cellular respiration equation: O₂ + glucose → CO₂ + H₂O + ATP

Cell Theory and Types of Cells

• Cell theory principles: All organisms have cells, cells are the basic unit, cells originate from preexisting cells.
• Prokaryotic cells lack a nucleus, while eukaryotic cells possess a nucleus.

DNA and RNA Structure

• DNA base pairing rules: A-T, C-G.
• RNA structure differs from DNA by containing uracil (U) instead of thymine (T) and being single-stranded.

Mutations and Genetic Variation

• Mutation: A change in DNA sequence, potentially beneficial, harmful, or neutral.
• Mutations drive evolution by providing variation that can lead to adaptations.

Protein Synthesis and Gene Expression

• Central dogma of biology: DNA → RNA → Protein
• A gene becomes a protein through transcription and translation (DNA to RNA to protein).

Meiosis and Sexual Reproduction

• Meiosis creates sex cells (gametes, sperm/egg) with half the DNA for diversity.
• Meiosis differs from mitosis by producing different cells for reproduction.

Punnett Squares and Probability

• Punnett square displays possible genetic combinations for offspring.
• Genotype: Genetic makeup (AA, Aa, aa).
• Phenotype: Measurable physical characteristics (blue eyes, brown hair).

Evolution and Fossil Evidence

• Fossils demonstrate species changes over time, supporting evolution.
• Homologous structures: Similar structures indicate common ancestry.

Speciation and Adaptations

• Speciation: Formation of new species via evolution.
• Adaptation: Trait enhancing survival in an environment.

Human Body Systems

• Circulatory system circulates blood, oxygen, and nutrients.
• Nervous system transmits signals between brain and body.

Immune System and Disease

• Immune system fights infections using white blood cells and immunity formation.
• Viruses require a host to reproduce, but bacteria can reproduce independently.

Endocrine System and Hormones

• Endocrine system regulates bodily functions via hormones.
• Insulin lowers blood glucose, Glucagon raises blood glucose.

Homeostasis and Feedback Loops

• Homeostasis: Body's maintenance of balance (e.g., temperature regulation).
• Feedback loops guide adjustments to maintain homeostasis.

Human Impact on the Environment

• Climate change: Rise in global temperatures due to increased CO₂ emissions.
• Deforestation reduces oxygen, increasing CO₂.

Renewable and Nonrenewable Resources

• Renewable resources can be replaced, like solar and wind.
• Nonrenewable resources are finite, like coal and oil.

Energy Flow in Ecosystems

• 10% rule: Only 10% of energy transfers to the next trophic level.

Miscellaneous Topics

• Decomposers recycle nutrients.
• Vaccines train the immune system to recognize and fight diseases.
• Genetic diversity aids species survival.