Cumulative exam

What is Science?

A method of understanding the natural world through observation and experimentation.

What is Biology?

The scientific study of life and living organisms.

What are the steps of the scientific method?

Observation → Question → Hypothesis → Experiment → Results → Conclusion.

What is a hypothesis?

A testable prediction.

What is a theory?

A well-supported explanation backed by evidence.

What is the hierarchical organization of living things?

Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism → Population → Community → Ecosystem → Biosphere.

What are the characteristics of life?

Made of cells, use energy, grow and develop, reproduce, respond to stimuli, maintain homeostasis, evolve over time.

What is an atom?

The basic unit of matter consisting of protons, neutrons, and electrons.

What is the octet rule?

Atoms react to fill their outer electron shell (usually 8 electrons), becoming stable.

What is the difference between atomic number and atomic weight?

Atomic number = number of protons; atomic weight = number of protons + number of neutrons.

What are covalent bonds?

Bonds where electrons are shared between atoms.

What are ionic bonds?

Bonds formed by the transfer of electrons from one atom to another.

What are hydrogen bonds?

Weak attractions between polar molecules.

Why is water important to life?

It acts as a solvent, has cohesive and adhesive properties, buffers temperature, and participates in chemical reactions, like hydrolysis.

What are organic compounds?

Compounds that contain carbon.

What are monomers and polymers?

Monomers are the building blocks (e.g., monosaccharides); polymers are chains of monomers (e.g., polysaccharides).

What is hydrolysis?

A reaction that breaks bonds by adding water.

What is dehydration synthesis?

A reaction that forms bonds by removing water.

What are the functions of carbohydrates?

Provide energy and structural support.

What are the functions of lipids?

Provide insulation, make up membranes.

What are the functions of proteins?

Structures, enzymes, and other functions.

What are the roles of nucleic acids?

Store and transmit genetic information.

What is cell theory?

All organisms are made of cells; the cell is the basic unit of life; all cells come from pre-existing cells.

What is the difference between prokaryotic and eukaryotic cells?

Prokaryotes lack a nucleus and organelles; eukaryotes have both.

What is the endosymbiotic theory?

The theory that mitochondria and chloroplasts originated from free-living bacteria that were engulfed by ancestral cells.

What is the function of the nucleus?

DNA storage.

What is the function of mitochondria?

ATP production.

What are ribosomes responsible for?

Protein synthesis.

What is the function of the rough endoplasmic reticulum (ER)?

Transport and synthesis of proteins.

What is the function of the Golgi apparatus?

Packaging and distribution of proteins.

What is the Plasma membrane?

A flexible bilayer of phospholipids with embedded proteins.

What is diffusion?

Movement of molecules from high to low concentration.

What is osmosis?

Diffusion of water across a semi-permeable membrane.

What is passive transport?

Transport of molecules without energy expenditure.

What is active transport?

Movement of molecules against their concentration gradient requiring energy.

What is facilitated diffusion?

Transport of molecules across a membrane via proteins.

What does hypertonic mean?

Solution with a higher concentration of solutes compared to another.

What does hypotonic mean?

Solution with a lower concentration of solutes compared to another.

What does isotonic mean?

Solution with equal concentrations of solutes.

What is plasmolysis?

The shrinking of plant cells due to loss of water.

What is lysis?

The bursting of animal cells due to excessive water intake.

What is crenation?

The shriveling of animal cells when placed in a hypertonic solution.

What is turgidity?

The state of being swollen or firm in plant cells due to water.

What is energy?

The capacity to do work.

What are the forms of energy?

Kinetic, potential, chemical, thermal, etc.

What is the first law of thermodynamics?

Energy cannot be created or destroyed.

What is the second law of thermodynamics?

Energy transformations increase entropy.

What is the ATP/ADP cycle?

ATP stores energy; when phosphate is removed, ADP is formed and energy is released.

What are coupled reactions?

Pairing an exergonic reaction with an endergonic one.

What are exergonic reactions?

Reactions that release energy.

What are endergonic reactions?

Reactions that absorb energy.

What are enzymes?

Proteins that speed up chemical reactions.

What factors affect enzymes?

pH, temperature, inhibitors, and substrate concentration.

What are redox reactions?

Reactions that involve the transfer of electrons.

What is cellular respiration?

The process of converting glucose to ATP.

What is fermentation?

Anaerobic process to generate ATP by converting glucose into ethanol or lactic acid.

What is glycolysis?

The breakdown of glucose to produce ATP and NADH.

What is the Krebs cycle?

The series of reactions that produce ATP, NADH, and FADH₂ from the oxidation of acetyl-CoA.

What is the electron transport chain (ETC)?

A series of complexes that transfer electrons and pump protons to produce ATP.

Where does glycolysis occur?

In the cytoplasm.

Where do the Krebs cycle and ETC occur?

In the mitochondria.

What is the ultimate energy source for life?

The Sun.

What adaptations do leaves have to prevent water loss?

Cuticle, stomata, and guard cells.

What are the main requirements for photosynthesis?

Sunlight, carbon dioxide (CO₂), water, and chlorophyll.

What is the photosynthesis equation?

6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂.

What are the products of light-dependent reactions in photosynthesis?

ATP, NADPH, and oxygen (O₂).

What does the Calvin cycle produce?

Glucose from carbon dioxide, ATP, and NADPH.

When is oxygen generated in photosynthesis?

During light-dependent reactions when water is split.

How do photosynthesis and respiration differ?

Photosynthesis is endergonic and stores energy; respiration is exergonic and releases energy.

What are the stages of the cell cycle?

Interphase (G₁, S, G₂), Mitosis (Prophase → Telophase), and Cytokinesis.

What is binary fission?

Asexual reproduction in prokaryotes where a cell divides into two identical cells.

What are the stages of mitosis?

Prophase, Metaphase, Anaphase, Telophase.

How does mitosis differ in plant and animal cells?

Plants form a cell plate; animals form a cleavage furrow.

What are the steps of meiosis?

Meiosis I: homologous chromosomes separate; Meiosis II: sister chromatids separate.

What is crossing over?

The exchange of genes between homologous chromosomes during Prophase I of meiosis.

What is independent assortment?

The random distribution of homologous chromosomes during Metaphase I.

What is the difference between diploid and haploid?

Diploid (2n) cells have two sets of chromosomes; haploid (n) cells have one set.

What is the difference between gametes and somatic cells?

Gametes are reproductive cells; somatic cells are body cells.

What is the difference between mitosis and meiosis?

Mitosis produces 2 identical cells; meiosis produces 4 unique gametes.

What does dominant and recessive mean in genetics?

Dominant traits are expressed if present; recessive traits require two copies to be expressed.

What is a gene?

A segment of DNA that codes for a protein.

What is an allele?

A variant form of a gene.

What is a phenotype?

The set of physical traits of an organism.

What is a genotype?

The genetic makeup of an organism.

What are the phenotypic ratios in monohybrid and dihybrid crosses?

Monohybrid: 3:1; Dihybrid: 9:3:3:1.

What is the Law of Segregation?

Alleles segregate during gamete formation.

What is the Law of Independent Assortment?

Genes located on different chromosomes assort independently.

What is incomplete dominance?

A genetic scenario where the phenotype of heterozygotes is a blend of the two alleles.

What is codominance?

A scenario where both alleles are expressed equally in the phenotype.

What is polygenic inheritance?

Inheritance of traits controlled by multiple genes.

How are human blood groups inherited?

Through multiple alleles (A, B, O) with codominance for A and B.

What are classes of genetic diseases?

Autosomal dominant, autosomal recessive, X-linked recessive, and mitochondrial.

What is chromosomal nondisjunction?

Failure of chromosomes to separate properly, leading to conditions like Down syndrome.

What is the structure of DNA?

A double helix composed of nucleotides with base pairs A-T and C-G.

What happens during transcription?

The process of creating mRNA from a DNA template.

What happens during translation?

The synthesis of proteins from mRNA at ribosomes with tRNA and rRNA.

Why is gene regulation necessary?

To ensure correct gene expression.

What are restriction enzymes?

Enzymes that cut DNA at specific sequences.

What is cloning?

The process of creating copies of genes or cells.

What is DNA fingerprinting?

A method used to identify individuals based on their unique DNA patterns.