MCAT Biology Chapter 1: The Cell Questions and Answers

MCAT Biology Chapter 1: The Cell Questions and Answers What are the four tenants of the cell theory? - Correct Answer️️ --All living things are composed of cells. -The cell is the basic functional unit of life. -Cells arise only from pre-existing cells -Cells carry genetic information in the form of DNA Why are viruses not considered living organisms? - Correct Answer️️ -They violate the cell theory; -their genetic material is RNA -they cannot reproduce on their own, they must invade another organism. Are eukaryotic cells unicellular or multicellular? - Correct Answer️️ -They can be both Whats the difference eukaryotic and prokaryotic cells in reference to the nucleus? - Correct Answer️️ -Eukaryotes have a true nucleus enclosed in the membrane, prokaryotes do not. What are the characteristics of the various layers of the phospholipid bilayer? - Correct Answer️️ -Hydrophilic: has electrostatic interactions with the aqueous environments. Hydrophobic: provides a highly selective barrier. What is DNA composed of? - Correct Answer️️ -Genes: coding regions for particular proteins. What is the relationship between DNA, chromosomes, histone, and the nucleus? - Correct Answer️️ -DNA is wrapped around histones (proteins) and then further wound into chromosomes (linear); chromosomes are located in the nucleus. What is transcription? Where does it occur? - Correct Answer️️ -The transformation of DNA to mRNA (DNA>hnRNA>mRNA) by RNA polymerase. In the nucleus. What is translation? - Correct Answer️️ -The formation of a peptide from mRNA What is the function of the nucleolus? - Correct Answer️️ -It synthesizes ribosomal RNA (rRNA). What is the function of the outer membrane of the mitochondria? - Correct Answer️️ -It separates the cytosol from inner mitochondrial environment. What is the function of the inner membrane of the mitochondria which contains cristae? - Correct Answer️️ -Contains enzymes and molecules necessary for the electron transport chain. What is responsible for the proton-motive force of the mitochondria? - Correct Answer️️ -Protons pumping from the mitochondrial matrix to the intermembrane space What is the significance of the proton-motive force in mitochondria? - Correct Answer️️ -Protons flow through ATP synthase to generate ATP during oxidative phosphorylation. Why is the mitochondria considered semi-autonomous? - Correct Answer️️ -They contain their own genes and replicate independently via binary fiss