TAMU BIO 111 LAB PRACTICAL TEST QUESTIONS AND ANSWERS 2024

The Cell Theory 1. Organisms consist of one or more cells 2. Cells are the smallest living things 3. Cells are formed by division of previous cells The Gene Theory DNA sequences may be altered by mutation or by crossing over and segregation during meiosis Brainpower Read More The Theory of Heredity Changes in DNA sequences produce individual heritage variation. Theory of Evolution Genetic change over time; Survival of the fittest Scientific Process 1. make observations 2. develop hypothesis 3. design experiment 4. colect data 5. analyze data 6. repeat experiment 7. share results ind, dep, and controlled variable ind- whats changing dep- what are you measuring controlled- constant Microscope used to observe termites Dissecting microscope Difference b/w dissecting and compound microscopes Dissecting use transmitted and reflected light; compound use only transmitted light Dissecting microscopes Lower magnification, greater resolution Transmitted (passes through) AND reflected (bounces off) light Ability to see 3D objects Compound Microscope Total Magnification Formula Oculars x Objective ex) 10 x 40 = 400 Water properties... 4 things -polar -solvent -unusual thermal properties -low viscosity Cohesion Water molecules attracted to eachother Surface tension: causes water to pull itself into the smallest surface area shape Adhesion Water molecules attracted to other objects Covalent Bond 2 atoms share 2 electrons within a molecule Can be polar or non polar Are very very strong Hydrogen Bond Occusr b/w 2 molecules when a positive hydrogen atom bonds with a negative oxygen, fluorine, or nitrogen anthocyanins pigment in plants ex. red cabbage Ionic bonds attraction between oppositely charged ions ex. NaCl Cation vs Anion cation- loses electron and positively charged anion- gains electron and negatively charged Chromatography Components of mixed solution are separated along the matrix pH -potential of hydrogen in a solution -neutral pH: 7 -acid Solutions: <7 -basic Solutions: >7 pH = -log [H+] Acid Base Indicators Estimate pH of a solution with color change interval (Best way to get pH measurement is w/ pH meter) Plasma membrane -phospholipid bilayer -hydrophillic heads -hydrophobic tails -selectively permeable Diffusion Solute molecules go from high to low concentration Osmosis diffusion of water molecules across a plasma membrane, low to high concentration Facilitated Diffusion Relies on carrier proteins to bind and carry substances through tunnel channels in the plasma membrane Active Transport Requires ATP to move against concentration gradient Hypotonic, Hypertonic, and Isotonic Solution hypotonic- lower, bursts hypertonic- higher, shriveled isotonic- equal Osmotic and Turgor Pressure osmotic- pressure needed to stop movement of water turgor- pressure that pushes cell membrane against cell wall Functional Groups hydroxyl, carbonyl (aldehyde and ketone), carboxyl, amino, sulfhydryl Saccharides Carbohydrates 4 Key Functions 1. Supply carbon for synthesis of other biomolecules 2. Form structural components 3. Provide fuel for cellular metabolism 4. Poly - store glucose for later use Lipids -energy storage -vitamins -triglycerides, phospholipids, sterols -nonpolar Monosaccharides -Simple sugars that occur in ring and linear form -Can be identified w/ BENEDICT'S reagent Aldehyde organic compound that contains hydrogen