Title: Biology Basics — LearnCoachAssist

Q: What is biology?
A: Biology is the scientific study of life and living organisms, encompassing their structure, function, growth, origin, evolution, and distribution.

Q: What are the seven characteristics of life?
A: The seven characteristics are organization (cells), metabolism, homeostasis, growth, reproduction, response to stimuli, and adaptation through evolution.

Q: What are the levels of biological organization from simplest to most complex?
A: The levels are atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and biosphere.

Q: What is a cell?
A: A cell is the basic structural and functional unit of all living organisms, often called the 'building block of life'.

Q: What is the cell theory?
A: The cell theory states that all living things are composed of cells, cells are the basic unit of life, and all cells come from pre-existing cells.

Q: What is the difference between prokaryotic and eukaryotic cells?
A: Prokaryotic cells lack a nucleus and membrane-bound organelles (e.g., bacteria), while eukaryotic cells have a nucleus and organelles (e.g., plants, animals).

Q: What is the function of the cell membrane?
A: The cell membrane, or plasma membrane, regulates what enters and exits the cell, maintains homeostasis, and facilitates communication using a phospholipid bilayer with embedded proteins.

Q: What is the cytoplasm?
A: Cytoplasm is the gel-like substance inside the cell membrane but outside organelles, where many cellular processes occur and organelles are suspended.

Q: What is the role of the nucleus?
A: The nucleus houses the cell's DNA, controls cellular activities like growth and reproduction, and is the site of RNA synthesis.

Q: What is the function of mitochondria?
A: Mitochondria are the 'powerhouses' of the cell, producing ATP through cellular respiration by breaking down glucose.

Q: What are ribosomes?
A: Ribosomes are small structures that synthesize proteins by translating mRNA into polypeptide chains; they can be free in cytoplasm or attached to the endoplasmic reticulum.

Q: What is the rough endoplasmic reticulum (RER)?
A: The RER is studded with ribosomes and modifies proteins destined for secretion or membranes, folding and adding carbohydrates.

Q: What does the smooth endoplasmic reticulum (SER) do?
A: The SER synthesizes lipids, detoxifies drugs and poisons, and stores calcium ions in muscle cells.

Q: What is the Golgi apparatus?
A: The Golgi apparatus modifies, sorts, and packages proteins and lipids into vesicles for secretion or use within the cell.

Q: What are lysosomes?
A: Lysosomes are membrane-bound sacs containing hydrolytic enzymes that break down waste materials, cellular debris, and pathogens through digestion.

Q: What is the main function of vacuoles?
A: Vacuoles store water, nutrients, and waste; in plants, the central vacuole maintains turgor pressure and cell rigidity.

Q: What are chloroplasts?
A: Chloroplasts are organelles in plant cells that perform photosynthesis, converting light energy into chemical energy stored in glucose using chlorophyll.

Q: What are the four main types of biological macromolecules?
A: The four are carbohydrates (energy/storage), lipids (energy storage/insulation), proteins (structure/enzymes), and nucleic acids (genetic information).

Q: Why is water essential to life?
A: Water is a universal solvent, aids in transport, regulates temperature, participates in hydrolysis reactions, and maintains cell shape via cohesion and adhesion.

Q: What are enzymes?
A: Enzymes are biological catalysts, mostly proteins, that speed up chemical reactions by lowering activation energy without being consumed.

Q: What is pH and its importance in biology?
A: pH measures hydrogen ion concentration (0-14 scale); most biological processes require neutral pH around 7, as enzymes denature outside optimal ranges.

Q: What is photosynthesis?
A: Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water.

Q: What is the overall equation for photosynthesis?
A: 6CO_2 + 6H_2O + light energy → C_6H_12O_6 + 6O_2

Q: What occurs in the light-dependent reactions of photosynthesis?
A: Light-dependent reactions capture sunlight in thylakoids, splitting water to produce ATP, NADPH, and oxygen; these energy carriers go to the Calvin cycle.

Q: What is the Calvin cycle?
A: The Calvin cycle, or light-independent reactions, uses ATP and NADPH to fix CO_2 into glucose in the stroma of chloroplasts.

Q: What is cellular respiration?
A: Cellular respiration is the process cells use to break down glucose into ATP, releasing energy for cellular work, primarily in mitochondria.

Q: What is glycolysis?
A: Glycolysis is the first stage of cellular respiration, occurring in cytoplasm, where glucose splits into two pyruvate molecules, producing 2 ATP and 2 NADH.

Q: What is the Krebs cycle (Citric Acid Cycle)?
A: The Krebs cycle oxidizes acetyl-CoA from pyruvate in the mitochondrial matrix, producing CO_2, ATP, NADH, and FADH_2.

Q: What is the electron transport chain?
A: The electron transport chain in the inner mitochondrial membrane uses electrons from NADH/FADH_2 to pump protons, creating a gradient for ATP synthase to produce ATP via oxidative phosphorylation.

Q: What is the overall equation for cellular respiration?
A: C_6H_12O_6 + 6O_2 → 6CO_2 + 6H_2O + ATP

Q: What is mitosis?
A: Mitosis is cell division producing two identical diploid daughter cells for growth, repair, and asexual reproduction; it includes prophase, metaphase, anaphase, telophase.

Q: What are the stages of mitosis in order?
A: Stages are prophase (chromosomes condense), metaphase (line up at equator), anaphase (sister chromatids separate), telophase (nuclei reform), followed by cytokinesis.

Q: What is meiosis?
A: Meiosis is cell division producing four non-identical haploid gametes for sexual reproduction, involving two divisions and genetic recombination.

Q: How does meiosis differ from mitosis?
A: Mitosis produces two diploid identical cells; meiosis produces four haploid genetically diverse cells with crossing over and independent assortment.

Q: What is DNA?
A: DNA (deoxyribonucleic acid) is a double-helix molecule storing genetic information in nucleotides (A, T, C, G) as the hereditary material in nearly all organisms.

Q: What is the structure of a DNA nucleotide?
A: A nucleotide consists of a deoxyribose sugar, phosphate group, and nitrogenous base (adenine, thymine, cytosine, or guanine).

Q: What is the complementary base pairing in DNA?
A: Adenine (A) pairs with thymine (T) via two hydrogen bonds; cytosine (C) pairs with guanine (G) via three hydrogen bonds.

Q: What is RNA?
A: RNA (ribonucleic acid) is a single-stranded nucleic acid with uracil (U) instead of thymine; types include mRNA, tRNA, rRNA for protein synthesis.

Q: What is transcription?
A: Transcription copies a DNA gene into mRNA in the nucleus; RNA polymerase binds promoter, reads template strand, producing complementary mRNA.

Q: What is translation?
A: Translation synthesizes proteins at ribosomes; tRNA brings amino acids matching mRNA codons via anticodons, forming polypeptide chains.

Q: What is a gene?
A: A gene is a segment of DNA that codes for a specific protein or RNA molecule, determining traits.

Q: What is a mutation?
A: A mutation is a change in DNA sequence; types include point mutations, insertions, deletions, causing variations or diseases like sickle cell anemia.

Q: What are Mendel's laws of inheritance?
A: Law of Segregation: alleles separate during gamete formation; Law of Independent Assortment: genes for different traits assort independently.

Q: What is a Punnett square?
A: A Punnett square predicts offspring genotypes from parental gametes; e.g., for monohybrid cross, shows ratios like 3:1 phenotypic.

Q: What determines human blood types?
A: Blood types (A, B, AB, O) are determined by ABO gene alleles on antigens; Rh factor adds + or - based on another gene.

Q: Who is Charles Darwin and his key idea?
A: Charles Darwin proposed natural selection in 'On the Origin of Species'; organisms with favorable traits survive and reproduce more.

Q: What is natural selection?
A: Natural selection is the differential survival/reproduction of individuals due to heritable variations best suited to environment, driving evolution.

Q: What are the five kingdoms of life?
A: Kingdoms are Monera (bacteria), Protista (protists), Fungi (fungi), Plantae (plants), Animalia (animals).

Q: What are viruses?
A: Viruses are non-living infectious agents with genetic material in protein coat; they replicate only inside host cells, lacking metabolism.

Q: What is biodiversity?
A: Biodiversity is the variety of life at genetic, species, and ecosystem levels; essential for ecosystem stability and human well-being.

Q: What is an ecosystem?
A: An ecosystem is a community of living organisms interacting with non-living components (abiotic factors) like climate and soil in a specific area.

Q: What is a food chain?
A: A food chain shows energy transfer from producers (plants) to consumers (herbivores, carnivores) to decomposers, linearly.

Q: What is a food web?
A: A food web is interconnected food chains in an ecosystem, showing complex feeding relationships and greater realism.