PENN FOSTER BIOLOGY PROCTORED EXAM LATEST 200 QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS) AGRADE

What is an enzyme? - ANSWER Catalysts that increase the speed of a chemical reaction without undergoing any permanent chemical change What is the process of photosynthesis? - ANSWER -The process in which the Sun's energy is converted into chemical energy (occurs in chloroplasts). -Carbon dioxide and water are added -Sugar and oxygen are produced What is cellular respiration? - ANSWER Cellular respiration is the process that releases energy from food in the presence of oxygen. What is the cellular respiration equation? - ANSWER 6O2 + C6H12O6 - 6CO2 + 6H2O + Energy What is glycolysis? - ANSWER "splitting sugars." yields two molecules of ATP. What is Krebs cycle? - ANSWER This term refers to a series of chemical reactions that involve the complete oxidation of acetyl CoA and produce 2 mol of ATP (energy) along with hydrogen and carbon, which combine with oxygen to form (H2O) and (CO2). What is the electron transport chain? - ANSWER Is a sequence of electron carrier molecules that shuttle electrons, down a series of reactions that release energy; used to make ATP. What is cellular reproduction? - ANSWER Process by which cells divide to form new cells Growth phase- cell duplicates its contents and DNA Cell Division- the cytoplasm and DNA of a parent cell are distribute to 2 daughter cells How many chromosomes do humans have? - ANSWER 46 (23 pairs) What is nondisjunction and when does it occur? - ANSWER Nondisjunction occurs when chromosomes do not separate properly during cell division. This can form a gamete with an extra chromosome or one missing part or all of a chromosome (aka monosomy or trisomy). OCCURS DURING ANAPHASE 1 & 2 Characteristics of living things - ANSWER -All are composed of cells -All obtain energy and use it to develop -Can sense changes in the environment and adjust in response to change -Exhibit modifications that represent adaptations to their environment Levels of Biological Organization - ANSWER atom, molecule, organelle, cell, tissue, organ, organ system, organism How are organisms classified? - ANSWER on the basis of their evolutionary/genetic relatedness What is the scientific method? What is it's importance in biological sciences? - ANSWER Process used to validate observations while minimizing observer bias It's goal is for research to be conduced in a fair, unbiased and repeatable manner. The best way to discover how and why the world works