Biodiversity and Cell Structure Quiz

Biodiversity and Classification

• Importance of Biodiversity: Crucial for ecosystem stability, resilience, and human survival. Provides essential ecosystem services (food, water, medicine, pollination). Diverse ecosystems are more resilient to disturbances. Biodiversity provides resources (e.g., Rosy Periwinkle for cancer treatment). Cultures often rely on biodiversity for traditions and livelihoods.
• Threats to Biodiversity: Habitat loss (urbanization, agriculture, deforestation), pollution (air, water, soil), climate change (shifts in temperature, precipitation, seasons), invasive species, and overexploitation are major threats.
• Taxonomic System (DKPCOFGS): Hierarchical system of classifying organisms (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species). Organisms are categorized based on shared traits.
• Binomial Nomenclature: Two-part naming system (Genus species) for organisms, e.g., Homo sapiens. The genus is capitalized, the species lowercase, both italicized or underlined.
• Dichotomous Keys: Tools used to identify organisms based on their characteristics. These tools use a series of yes/no questions regarding characteristics.
• Domains and Kingdoms: Three domains (Bacteria, Archaea, Eukarya). Eukarya includes four kingdoms (Protista, Fungi, Plantae, Animalia). Bacteria and Archaea each have one kingdom. Bacteria are single-celled and prokaryotic. Some are beneficial (gut bacteria) or harmful ( E. coli). Archaea are like bacteria but live in extreme environments. Protists are mostly unicellular eukaryotes; some autotrophic (algae), some heterotrophic (amoebas). Fungi are decomposers (mushrooms, yeasts, molds) and absorb nutrients from dead organisms. Plantae are multicellular autotrophs that photosynthesize. Animalia are multicellular heterotrophs with complex organ systems..

Cell Structure and Viruses

• Eukaryotic vs. Prokaryotic Cells: Eukaryotic cells have membrane-bound organelles (like a nucleus), while prokaryotic cells lack them. The DNA in prokaryotic cells is in a region called the nucleoid. Eukaryotic are larger and more complex, prokaryotic are smaller and simpler. Examples of eukaryotic cells include animal, plant, fungal and protist. Examples of prokaryotic cells are Bacteria and Archaea.
• Endosymbiosis Theory: Eukaryotic cells emerged from prokaryotic cells engulfing other cells (e.g., mitochondria, chloroplasts). This theory is supported by their similar size and structure to modern-day bacteria, and their own DNA.
• Viruses: Non-living entities composed of a protein coat (capsid) and genetic material (RNA or DNA).
• Viral Cycles:
• Lytic Cycle: Virus replicates, the host cell bursts (lyses).
• Lysogenic Cycle: Viral DNA integrates into host DNA, replicates with host, can later enter lytic cycle.

Genetics

• DNA Structure: DNA is a double-stranded molecule twisted into a helical shape.
• Nucleotides: The building blocks of DNA, composed of a phosphate group, sugar, and a nitrogenous base. (Adenine, Thymine, Cytosine, Guanine).
• Base Pairing: Adenine (A) pairs with Thymine (T), Guanine (G) pairs with Cytosine (C).
• Chromosomes:
• Haploid vs. Diploid: Haploid cells have one set of chromosomes (gametes), diploid cells have two sets (somatic cells).
• Autosomes vs. Sex Chromosomes: Autosomes are non-sex chromosomes; sex chromosomes determine sex (XX or XY).
• Cell Division:
• Cell Cycle: Interphase (growth, DNA replication) and Mitotic Phase (mitosis or meiosis).
• Mitosis: Cell division for growth/repair, produces two identical diploid cells. The stages include Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.
• Meiosis: Cell division for sexual reproduction, produces four non-identical haploid cells including two rounds of division (Meiosis I and Meiosis II).
• Genetic Variation: Mutations and genetic recombination (crossing over during meiosis.)
• Heredity: Mendel’s Laws (Segregation, Independent Assortment) explain inheritance patterns. Punnett squares.

Animal Structure and Function

• Circulatory System: Blood components (red blood cells, white blood cells, platelets, plasma); heart structures (atria, ventricles, valves); blood pathway; cardiac output (heart rate × stroke volume), heart sounds and blood pressure.
• Respiratory System: Organs (nasal cavity, trachea, bronchi, alveoli); breathing mechanisms; lung capacity; diseases (asthma, COPD). Oxygen enters the nose, passes through the trachea, bronchi, bronchioles, to the alveoli.
• Digestive System: Organs (mouth, esophagus, stomach, small intestine, large intestine, liver, pancreas, gallbladder); mechanical and chemical digestion; enzymes (amylase, protease, lipase); digestive disorders (ulcers, acid reflux).

Evolution

• Darwin's Observations: Biogeography, fossils, bird collections (finches with different beak shapes).
• Evidence for Evolution: Homologous vs. Analogous Structures, Embryonic Evidence, Vestigial Features, Fossil Record and DNA.
• Natural Selection: Survival of the fittest based on advantageous traits.
• Types of Selection: Directional, stabilizing, disruptive, sexual.
• Artificial and Sexual Selection: Human or mate choice based selection.
• Genetic Drift: Bottleneck Effect and Founder Effect.
• Speciation: Reproductive isolating mechanisms (pre-zygotic and post-zygotic).
• Patterns of Evolution: Adaptive radiation, divergent evolution, convergent evolution, coevolution.