NLN PAX-RN Biology Exam 92 Questions with Answers 2023
What are the taxonomic levels of all living beings from most to least general? - CORRECT
... [Show More] ANSWER domain, kingdom, phylum, class, order, family, genus, species (dumb kings play chess on fiberGlass stools)
Define homeostasis. - CORRECT ANSWER The maintenance of equilibrium within an organism by a tendency to compensate for changes and disruptions.
Define metabolism. - CORRECT ANSWER All of the physical and chemical reactions associated with every aspect of cell life.
Define anabolism. - CORRECT ANSWER An organism's ability to synthesize larger molecules from smaller molecules.
Define catabolism. - CORRECT ANSWER An organism's ability to synthesize smaller molecules from larger ones.
By what process is ATP produced? - CORRECT ANSWER oxidative phosphorylation (OXYPHOS)
What is the process by which glycogen is converted to energy? - CORRECT ANSWER glycogenolysis
What are the two main types of chemical bonds? - CORRECT ANSWER Ionic and covalent.
How are ionic bonds formed? - CORRECT ANSWER Ionic bonds are formed when one or more electrons are transferred from one atom to another. One atom loses electrons and becomes positively charged. The other gains electrons and becomes negatively charged. These charged forms are called ions and are either positively or negatively charged. Na⁺ is an example of a positively charged ion that has lost an electron. Cl⁻ has gained an electron and is a negatively charged ion.
How are covalent bonds formed? - CORRECT ANSWER Covalent bonds are formed when electrons are shared by atoms, not pulled away completely.
If the electrons in a covalent bond are shared equally, what is the bond called? - CORRECT ANSWER nonpolar covalent
If the electrons in a covalent bond are shared unequally, what is the bond called? - CORRECT ANSWER polar covalent
What is a hydrogen bond? - CORRECT ANSWER Hydrogen bonds are weak chemical bonds formed when a hydrogen atom interacts with a nearby hydrogen atom that is already part of a covalent bond. Water molecules are held together by hydrogen bonds.
Is water a polar or nonpolar molecule? - CORRECT ANSWER A water molecule is a polar molecule as the hydrogen atoms exhibit a partial positive charge on one side, and the oxygen atom exhibits a partial negative charge on the other side.
What is a calorie? - CORRECT ANSWER The amount of heat it takes to increase the temperature of one g of H₂O by 1°C.
What is hydrolysis? - CORRECT ANSWER The breakdown of a compound (like food molecules in the human body) due to reaction with water.
Define pH. - CORRECT ANSWER pH is the value or measurement of acidity or basicity in an aqueous solution.
What is the pH of pure water? - CORRECT ANSWER 7.0 - neutral.
What is the normal pH range for human blood? - CORRECT ANSWER 7.35-7.45
What does NPO stand for and mean? - CORRECT ANSWER non per os - no food/drink
What is the difference between organic and inorganic compounds? - CORRECT ANSWER Organic compounds contain carbon. Inorganic compounds do not (with the exception of CO₂).
What are the four classes of organic compounds that are essential to all life on earth? - CORRECT ANSWER Proteins, Carbohydrates, Lipids and Nucleic Acids
What is a peptide bond? - CORRECT ANSWER A peptide bond is formed when two amino acids form a bond between them and then form a string of bonded amino acids (polypeptide chain).
What 3 elements make up carbohydrates? - CORRECT ANSWER carbon, oxygen and hydrogen
What are monosaccharides? - CORRECT ANSWER simple (one) sugars such as glucose and fructose
What are disaccharides? - CORRECT ANSWER (two sugars) such as sucrose, lactose and maltose
What are polysaccharides? - CORRECT ANSWER (many sugars) such as glycogen (the form in which animals store glucose), starch (the form in which plants store glucose) and cellulose (structural polysaccharide which forms the cell walls of plants)
What is the chemical formula of glucose? - CORRECT ANSWER C₆H₁₂O₆
Give 5 examples of lipids. - CORRECT ANSWER fats, waxes, phospholipids, oils, steroids
What are 3 functions of lipids? - CORRECT ANSWER structural components of cells, means of insulation, means of energy storage
What is another name for fats and why? - CORRECT ANSWER triglycerides - they contain 3 fatty acids and 1 glycerol molecule
What are HDLs? - CORRECT ANSWER High-density lipids. (good lipids)
What are LDLs? - CORRECT ANSWER Low-density lipids. (bad lipids)
What can too many LDLs lead to? - CORRECT ANSWER clogged arteries which can cause coronary diseases such as atherosclerosis and arteriosclerosis, which can cause heart attacks and cerebral vascular accidents (strokes).
What is cholesterol? - CORRECT ANSWER A unique organic lipid composed of hydrocarbon rings. Cholesterol is necessary to build and maintain cell membranes, as it gives the cell membrane plasticity so that it does not break. Cholesterol also functions to produce steroid hormones.
What are nucleotides? - CORRECT ANSWER a compound consisting of a nucleoside linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.
What are some examples of nucleic acids? - CORRECT ANSWER ATP (ADENOSINE TRI-PHOSPHATE), coenzymes (necessary for the transport of protons and electrons from one reaction site to the next), DNA, RNA.
What are the two types of cell? - CORRECT ANSWER eukaryotic and prokaryotic
What are eukaryotic cells? - CORRECT ANSWER Eukaryotic cells have a cell wall or a cell membrane (or both) forming their outer layers, cytoplasm where the organelles are located and a nucleus where the DNA/RNA and chromosomes are located.
Do plants, bacteria and fungi cells have a cell wall, a cell membrane or both? - CORRECT ANSWER both
Do animal cells have a cell wall, a cell membrane or both? - CORRECT ANSWER cell membrane only
What are prokaryotic cells? - CORRECT ANSWER Prokaryotic cells are much smaller than eukaryotic cells and do not contain a nucleus. Their genetic information is found within a nucleoid. A bacterium is an example of a prokaryotic cell.
What is another term for the cell membranes found in animal cells? - CORRECT ANSWER Plasma membrane.
What are the plasma membranes in animal cells made of? - CORRECT ANSWER phospholipids and proteins
What is the role of the cell membrane? - CORRECT ANSWER They regulate movement of substances into and out of the cell.
What is the spot on the cell membrane where substances can move in and out called? - CORRECT ANSWER the pinocyotic vesicle
What are plant cell walls made of? - CORRECT ANSWER Cellulose fiber - a polysaccharide
What are the cell walls of bacteria made of? - CORRECT ANSWER peptidoglycan (murein) - a polymer consisting of protiens and sugars
What are the cell walls of fungi made of? - CORRECT ANSWER Chitin - a polysaccharide similar to cellulose
What is the function of the nucleus in a eukaryotic cell? - CORRECT ANSWER control center - contains genetic information (DNA in the form of chromosomes) - responsible for the cell's ability to reproduce
What is the nucleolus and where is it located? - CORRECT ANSWER The nucleolus is in the nucleus and creates the ribosomes and the RNA.
What are ribosomes? - CORRECT ANSWER The sites of protein synthesis and secretion.
What is the endoplasmic reticulum? - CORRECT ANSWER Responsible for protein production and transport.
What do rough ER do? - CORRECT ANSWER Create proteins marked for transport out of the cell.
What do smooth ER do? - CORRECT ANSWER Smooth ER breaks down toxic chemicals and makes lipids, hormones and steroids.
What are golgi bodies? - CORRECT ANSWER Golgi bodies, like ribosomes and ER, participate in protein synthesis by modifying, processing, sorting and then packaging the final product in sacs called vesicles. These vesicles carry the final product to the cell membrane.
What are mitochondria? - CORRECT ANSWER The powerhouses of the cell, converting energy from organic molecules to ATP so that it can be used when needed in cell activity and homeostasis.
What are lysosomes? - CORRECT ANSWER Tiny sacs that carry digestive enzymes. They break down old, worn-out organelles, debris and large ingested products. They clear the cytoplasm of unwanted "flotsam".
What are centrioles? - CORRECT ANSWER Responsible for microtubule production necessary for cell division during reproduction. Microtubules pull apart replicated chromosomes and move them to opposite ends of the cell. Centrioles are common in animal cells but absent in plant cells.
What are vacuoles? - CORRECT ANSWER Fluid-filled storage sacks that store water, food, salts, wastes and pigments.
What are peroxisomes? - CORRECT ANSWER Found in cytoplasm, responsible for detoxification, produce H₂O₂. Also contain enzymes responsible for the breakdown of H₂O₂ into water and oxygen. They are common in liver and kidney cells.
What is a cytoskeleton? - CORRECT ANSWER Maintains the shape of the cell with a tiny network of fibers called microtubules and microfilaments.
What is tubulin? - CORRECT ANSWER Microtubules are made of this. It is also an important part of centrioles, flagella and cilia.
Name six transport phenomena by which substances can cross cell membranes. - CORRECT ANSWER diffusion, osmosis, facilitated diffusion, active transport, passive transport, bulk transport
What is diffusion? - CORRECT ANSWER The passive movement of a substance from an area of higher concentration to an area of lower concentration. (down a concentration gradient)
What is osmosis? - CORRECT ANSWER A passive process by which molecules of a solvent travel through a semipermeable membrane from an area of higher concentration (hypertonic) to an area of lesser concentration (hypotonic), equalizing the concentrations on each side of the membrane.
What is facilitated diffusion? - CORRECT ANSWER Passive transport in which the molecules require assistance from special membrane proteins to move substances across the cell membrane. Glucose and amino acids are examples of molecules which require transport assistance.
What is active transport? - CORRECT ANSWER Requires ATP (energy) to move materials such as ions, salts, glucose, and amino acids from an area of higher concentration to an area of lower concentration. EXAMPLES: sodium-potassium pump, endocytosis, phagocytosis, pinocytosis, exocytosis
What is bulk transport? - CORRECT ANSWER involves movements of larger molecules in one direction by pressure. Example: blood moving through vessel
What are enzymes? - CORRECT ANSWER Special proteins that act as catalysts to accelerate the reaction between specific substrates within a cell. Substrates are the substances acted upon by an enzyme. Vitamins, cofactors and coenzymes are examples of enzymes.
What are the results when a cell converts ATP to energy? - CORRECT ANSWER ATP→ADP+P+Energy
ADP is adenosine diphosphate. The cell hydrolizes the third phosphate.
How do plants produce ATP? - CORRECT ANSWER Photosynthesis
What are four events that occur in cellular respiration? - CORRECT ANSWER glycolysis, the Krebs cycle, electron transport chain and oxidative phosphorylation
What is the first step of cellular respiration? - CORRECT ANSWER glycolysis - the splitting of sugar which results in ADP energy and pyruvate or pyruvic acid. It occurs in the cytoplasm of the cell without oxygen present.
What is the second step in cellular respiration? - CORRECT ANSWER Transition reaction: Pyruvic acid is shuttled to the mitochondria where it is converted to a molecule of acetyl CoA for further breakdown.
What is the their step in cellular respiration ? - CORRECT ANSWER Krebs Cycle - (aka the Citric Acid Cycle) occurs in the mitochondrial matrix. In the presence of Oxygen gas (O₂), all the hydrogens (H₂) are stripped off the Acetyl CoA, two by two, to extract the electrons for making ATP, until there are no hydrogens left - and all that is left of the sugar is CO₂ - a waste product - and H₂O (exhale). The Krebs cycle results in the production of only ~4 ATPs, but produces a lot of NADH, which will go on to the next step... Hans Krebs won the Nobel Prize in 1953 for his discovery of the Citric Acid Cycle.
What does NADH stand for? - CORRECT ANSWER nicotinamide adenine dinucleotide
What is the fourth step in cellular respiration? - CORRECT ANSWER electron transport chain - Electrons from Hydrogen are carried by NADH and passed down an electron transport chain to result in the production of ATP. Results in the production of ~32 ATPs for every glucose. Peter Mitchell won the Nobel Prize in 1978 for his work on energy production in mitochondria, called the Chemiosmotic Theory.
DNA is... - CORRECT ANSWER ...a long polymer made up of repeating nucleotides.
DNA is ____-stranded and RNA is ____-stranded. - CORRECT ANSWER DNA is double-stranded and RNA is single-stranded.
Name the three very important parts of nucleotides. - CORRECT ANSWER 1) a five-carbon sugar (deoxyribose in DNA; Ribose in RNA)
2) a phosphate group (chemical group made up of oxygen and phosphorous)
3) a nitrogenous base (chemical unit composed of carbon, oxygen, hydrogen and nitrogen, held together by a weak hydrogen bond)
What are the nitrogen bases found in DNA? - CORRECT ANSWER adenine, guanine, cytocene, thymine
In RNA, _______ replaces thymine. - CORRECT ANSWER uracil
In the double helix, what are the pairings? - CORRECT ANSWER T-A; C-G
RNA compliments DNA and is responsible for assisting protein synthesis by what three basic steps? - CORRECT ANSWER transcription, RNA processing, translation
What is deletion? - CORRECT ANSWER type of chrmosome mutation in which a section of a chromosome is deleted
What is Insertion? - CORRECT ANSWER type of mutation in which one or more nucleotide base pairs are inserted
What is substitution? - CORRECT ANSWER aka "point mutation" - a single-base nucleotide is replaced with another nucleotide
What is a somatic cell? - CORRECT ANSWER a cell that makes up tissue, all non-reproductive cells in the human body are somatic cells
What happens if a mutation occurs in a somatic cell? - CORRECT ANSWER The mutation only affects that tissue.
What happens if a mutation occurs in a primary sex cell (egg or sperm)? - CORRECT ANSWER the mutation will be passed on to the offspring or by the gametes produced by that primary sex cell division
What is a gamete? - CORRECT ANSWER mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote. has only 23 chromosomes [Show Less]