BIOLOGY QUESTIONS AND ANSWERS 100% PASS

BIOLOGY QUESTIONS AND ANSWERS 100% PASS Cell Basic unit of structure of living cells. Cell Theory ~ All organisms are made up of cells, ~ Smallest organisational unit, Biogenisis Cells derived from pre-existing cells. Plasma Membrane Also known as the cell membrane. Separates the outside environment from inside of the cell as well as controlling what enters and exits the cell. Cytoplasm Made up of the cytosol, and organelles (Eukaryotes.) While 80% is water, it also contains ions, salts and organic molecules. DNA Holds the hereditary information that's passed between generations. Ribosomes These organelles are responsible for the synthesis of proteins. Prokaryotes - Unicellular, - Lacks nucleus, - No membrane-bound organelles, - Found in extreme conditions, - single DNA chromosomes, (genosphore), - Genosphore found in nucleoid, - Cell wall (prevents damage and dehydration), - Flagella - enables free movement, - Pili - involved in transferring DNA, Eukaryotes - Membrane bound organelles, - Nucleus, - Specialised organelles, - 'Cell Compartmentalisation' Kingdom of Classification Bacteria Single-celled organisms. Most numerous and oldest organism in the biosphere. Archaea Extremophiles. Organisms that live in extreme conditions, such as acidic, boiling or freezing conditions. Lipids Fatty organic compounds, composed of carbon, hydrogen. Organelle Membranes Allows each organelle to have their own composition. Also helps control the movement within the cell. Rough Endoplasmic Reticulum Processes and modifies proteins. Smooth Endoplasmic Retculum Synthesis lipids. Lysosome Digests cellular waste material and foreign matter. Mitochondrion Obtains energy from organic compounds and is the site of cell respiration. Chloroplast Uses light energy, carbon dioxide and water to produce glucose. Also the site of photosynthesis. Centriole Involved in cell division and formation of cell structures. Flagellum Mobility. Vacuole Stores substances and helps plant cells with their structure. Plastid Synthesis' and storage's various organic molecules. Cell Wall Cell structure and protection. Animal Cell Plant Cell Enzymes Proteins that act as biological catalysts. They only catalyse one type of reaction. Biological term for cell membrane semi / selectively / differentially permeable membrane Fluid Mosaic Fluid The structure of the cell membrane. Consisting of protein, lipids, phospholipid bilayer and more. Phospholipids The building block of Phospholipid Bilayer. Made up of a hydrophobic (doesn't like water) tail and hydrophilic (likes water) head. Protein Permanent (Integral), temporary (peripheral) or spanning the phospholipid bilayer (transmembrane.) Carrier Protein Change shape/form to allow certain shaped molecules through. Involved in Active Transport. Active Transport -Requires energy to move substances, -Can only occur through carrier proteins, -ATP is needed for this process, Carrier Protein changes shape to allow a substance to be pushed through. Endocytosis Materials are taken into the cell by being pocketed by the cell membrane. Exocytosis Vecsicle enclosing particles joins membrane to release enclosed material. Channel Protein Allow specific proteins through. Osmosis Diffusion of water molecules. ~Net movement of water molecules from an area of high water concentration to an area of low concentration. ~Water molecules move from area of low solute concentration to area of high concentration. (SALT SUCKS) Facilitated Diffusion A process in which substances move through the plasma membrane down the concentration gradient with the aid of carrier (transport) proteins; does not require the use of energy. Simple Diffusion The movement of particles from an area of high concentration to low until it is uniform throughout. Concentration effect on diffusion The concentration becomes uniform quicker if the bigger the difference in concentration. Temperature effect on diffusion Increasing the temperature increases the speed of the molecules movement. Particle size effect on diffusion The smaller the particle, the quicker the rate of diffusion through the membrane. Surface Area to Volume Ratio Having a larger surface area to volume ratio means more efficiency at exporting and taking in substances. Having a smaller surface area to volume ratios, hence decreases the efficiency of exchange. Concentration Gradient A difference in concentration of a solute between one region and another. Solute A substance dissolved in a fluid. Solvent A fluid in which a substance is dissolved. Hypertonic A solution with a higher concentration of solute, low concentration of water. Hypotonic A solution with a higher concentration of water, low concentration of solute. Isotonic Same concentration across the board. Crenated / Plasmolysed Shriveled and shrunk from cell wall. Lysed / Turgid Swelled and burst, Pushing against cell wall. Symbiosis Different species living together in a close partnership. Each species is called a symbiont. Producers Organisms that produce their own food. Decomposers Organisms that break down the dead remains of other organisms. Detrivitore Organism that obtains nutrients from decomposing material, non-living material, or animal waste. Scavengers Feed off of dead animals. Herbivores Organisms that feed on plant matter or other producers. Carnivores Organism that consumes other consumers- eats flesh. Trophic Level Different feeding levels on a food chain / web. Consumers An organism that obtains energy and nutrients by feeding on other organisms or their remains. Keystone species A species that influences the survival of many other species in an ecosystem. Bio-mimicry Biomimicry involves mimicking or copying structures or systems found in nature to develop new materials or products. Autotroph An autotroph is an organism that can obtain organic compounds by converting inorganic matter. Heterotroph A heterotroph obtains organic compounds from either a producer or other heterotrophs. Cellular Respiration A process that all cells do. It takes place in the mitochondria and creates energy that is stored in organic compounds. Cellular Respiration word formula Oxygen+Glucose->Carbon Dioxide+Water+Energy Photosynthesis A process used by plants and other organisms to convert light energy into food. Takes place in the Chloroplast. Photosynthesis word formula Carbon dioxide + water (with light) = Glucose and Oxygen Xylem Vessles Elongated dead plant cells that create long tubes that the water is drawn up to reach the leaves and branches. Root Hair Cells Cells in the roots of plants that have long extensions to increase surface area for the absorption of water and minerals. Stomata A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allow gas exchange between the environment and the interior of the plant. Leaf Structure Transpiration Passive movement of water from roots to leaves- 99% of which is lost through stomata. 1% used for metabolic processes. System A group of organs that work together to perform a vital task. Human Digestive System Mouth, oesophagus, stomach, small intestine, large intestine, + gall bladder and liver Function of Human Digestive System Digestion helps break down foods into waste and nutrients. Chemical Digestion Enzymes break down food into smaller molecules. Mechanical Digestion Physical breakdown of large pieces of food into smaller pieces. Enzymes Proteins that speed up chemical reactions in a cell. Proteases Enzymes that breakdown protein, present in saliva and gastric secretions. Amylases Digestive enzymes that converts the starch into maltose in our digestive system. Lipases enzymes that break down lipids into soluble fatty acids. Homeostasis Maintaining a constant internal environment at optimum levels. Factors under Homeostatic control - Blood glucose, - Body Temp, - Oxygen & C02 Concentration, - pH of blood tissue and fluids, Negative Feedback A corrective mechanism involving an action that directly opposes a variation from normal limits. Stimulus Change in environment. Receptor Detects and registers change in environment. Modulator / Mediator Processes change and relays information. Effector Organ, Gland or Tissue tasked with the output or secretion to cause the 'effect'. Response Outcome of adjustments. Insulin A peptide hormone produced and secreted by the Beta cells of the pancreas. Insulin targets cells in the body, especially the liver and muscle, and allows them to take glucose out of the blood (thus lowering blood glucose levels). Glucagon A hormone secreted by the pancreatic alpha cells that increase blood glucose concentration. Endotherms animals that maintain a constant body temperature and physiologically maintain it. Ectotherms animals that cannot regulate body temperature physiologically and rely on the environment. Ways of increasing temp -increasing rate of cellular metabolism, -increasing rate of respiration, -behavioural, -shivering, -vasoconstriction, -piloerection, Ways of lowering temp -sweating, -vasodilation, -behavioural, Osmoregulation The control of water balance in organisms living in hypertonic, hypotonic, or terrestrial environments. What happens when the blood water levels are too low? 2. Hypothalamus detects it, 3. and processes change and initiates response, 4. Pituatry gland releases lots of ADH so high volume of water is absorbed by the kidney and small volumes of concentrated urine are passed to bladder and water is absorbed back into blood, 5. Water level returns to normal. Vice Versa. Mutalism When both species benefit. Communalism One species benefits and the other is neither harmed or helped. Parasitism One species benefits, the other is harmed. Predation Consumers that capture and eat other consumers, (Predator and Prey.) Amensalism One species is killed or inhibited and the other is unaffected. Binomial Namenclature two word naming system developed by linnaeus in which each species is assigned a two part scientific word called Genus name Capitalized word, e.g 'Homo' sapiens Specific name Lower case word, e.g Homo 'sapiens' K.P.C.O.F.G.S Kingdom, Phylum, Class, Order, Family, Genus, Species