Biology 101, Exam 2 Questions And Answers.

Three cell parts found in all cells? - Answer-DNA, plasma membrane, and cytoplasm or ribosomes What is the cell theory? - Answer-The cell is the basic unit of life, all living things are made up of one or more cells, and all cells come from the reproduction of other cells Cells that do not have a nucleus are: - Answer-prokaryotes DNA in bacterial/prokaryotic cells forms a: - Answer-circle DNA in eukaryotic cells are: - Answer-linear Why are cells small? - Answer-Cells do not get very large because the surface area to volume ratio must be high to allow for the ready exchange of materials in and out of the cell What three cell parts are found ONLY in plant cells? - Answer-cell wall, chloroplasts, and the large/central vacuole What is Endosymbiosis? - Answer-The theory that some prokaryotic cells engulfed other prokaryotic cells thus forming membrane-bound structures (like mitochondria or chloroplasts) and ultimately giving rise to eukaryotic cells What is the organelle site of the reaction called CELLULAR RESPIRATION in eukaryotic cells? - AnswerMitochondria What do you call the site of PROTEIN and LIPID SYNTHESIS in eukaryotic cells is an ENDOMEMBRANE SYSTEM? - Answer-the Endoplasmic Reticulum What can you find in the nucleus? - Answer-the nucleolus and DNAHow can you distinguish between the ROUGH E.R. and the SMOOTH E.R.? - Answer-the presence of RIBOSOMES in the rough E.R. What are the three structures that enable cells to move? - Answer-cilia, flagella, and psuedopods What is found within the CHLOROPLASTS and is the site of PHOTOSYNTHESIS? - Answer-thylakoids What are the folds within the MITOCHONDRIA called? - Answer-cristae What are cytoplasmic bridges found between PLANT cells? (holes in the CELL WALL) - Answerplasmodesmata What are the cytoplasmic bridges found between ANIMAL cells? (openings in the CELL MEMBRANES) - Answer-gap junctions Which organelle contains DIGESTIVE ENZYMES? - Answer-the lysosome The lysosome is produced by the pinching off of portions of the membranes of the: - Answer-Golgi bodies/apparatus What is the site of PROTEIN SYNTHESIS? - Answer-Ribosomes What is the largest CYTOSKELETON component? - Answer-the microtubules What are the structures involved in CELL MOVEMENT that are made up of "9+2" microtubules? - Answer-Cilia and Flagella What are the pair of structures that are made up of 9 triplets of microtubules? - Answer-the centrioles Centrioles are involved in the movement of chromosomes during cell division and found only in: - Answer-Animal cellsDescribe the make-up of a CELL MEMBRANE - Answer-The cell membrane is made of a bilayer of PHOSPHOLIPIDS, with PROTEINS floating in them Describe a PHOSPHOLIPID - Answer-The hydrophilic PHOSPHATE HEADS face outward while the hydrophobic FATTY ACID TAILS face inward What is the simplest type of passive transport across the membrane? What does it do? - Answerdiffusion it allows the passage of non polar molecules across phospholipids What are two non polar molecules that pass across phospholipids? - Answer-Carbon DiOxide (CO2) and Oxygen (O2) If a protein is involved in passive transport across the membrane then the process is called: - Answerfacilitated diffusion If molecules taken into the cell go from a Low concentration of that substance outside the cell to a High concentration ([L] to [H]) inside the cell through a carrier protein, then what is the process called? And what does it need for energy? - Answer-It is called ACTIVE transport and needs ATP for energy What happens if a red blood cell is put in a HYPOtonic solution? - Answer-it will swell up and burst What happens if a red blood cell is put in a HYPERtonic solution? - Answer-it will shrivel (plasmolysis) What happens if a plant cell is put in a HYPOtonic solution? - Answer-it will become rigid since the central vacuole creates TURGOR PRESSURE pushing against the cell wall which prevents wilting What are two examples of ENDOCYTOSIS? What do they do? What do they require? - Answer-1. Phagocytosis (which means "cell eating") takes in LARGE molecules or cells 2. Pinocytosis (which means "cell drinking") takes in SMALL particles dissolved in fluidBOTH require ATP Glucose enters the cell through what process? Why? - Answer-Glucose enters the cell through the process of FACILITATED diffusion since it uses carrier proteins and does not require energy input (passive transport) Carbon DiOxide (CO2) and Oxygen (O2) enters the cell through the phospholipid bilayer by what process? Why? - Answer-They enter through the process of SIMPLE diffusion since they are non polar and do not require energy input (passive transport) How does water enter the cell, and by what process? - Answer-Water enters the cell through PROTEINS in the membrane called AQUAPORINS by the process of OSMOSIS which does not require energy input (passive transport) What does ACTIVE transport require? - Answer-ATP