Biology 196 Exam I Study Guide (Chapters 1-5)
Chapter 1: An Introduction to Biology
Concepts to Know
● The 12 principles of all biological organisms
● The order of biological organization (ie atom-molecule-cell-tissue-etc) ● How vertical descent and horizontal gene transfer work, how they are different ● The taxonomy of organisms in order (domain and all the supergroups) ● How evolution over time accounts for unity and diversity of organisms ● The different studies of levels of biological organization (ie anatomy, physiology, etc) ● The difference between a hypothesis, prediction, and theory
● The difference between discovery-based science and hypothesis testing, and the steps of the scientific method
We also discuss several other topics like What is the meaning of the hydrosphere?
1. A bird maintains a relatively stable internal body temperature on a cold day. This is an example of?
2. Populations of organisms change over the course of many generations. Many of these changes result in increased survival and reproduction. This phenomenon is? a. Evolution Don't forget about the age old question of What is the meaning of cytology?
3. A biologist is studying the living organisms in a valley in Western Colorado and their interactions with the environment. She is studying?
We also discuss several other topics like What is the difference between learning and performance?
a. An ecosystem
b. A community
c. The biosphere
d. A viable landmass
e. A population
4. Which of the following is an example of horizontal gene transfer? a. The transmission of an eye color gene from father to daughter
b. The transmission of a mutant gene causing CF from father to daughter c. The transmission of a gene conferring pathogenicity (the ability to cause disease) from one bacterial species to another
d. The transmission of a gene conferring antibiotic resistance from a mother cell to its two daughter cells
e. All of the above
5. The scientific name for humans is Homo sapiens. The name Homo is the _____ to which humans are classified?
d. Genus If you want to learn more check out What is the difference between primary and secondary sources?
6. The underlying factor that explains the unity and diversity of modern species is? a. Energy
d. Systems biology
e. All of the above
7. By observing certain desert plants in their native environment, a researcher proposes that they drop their leaves to conserve water. This is an example of?
a. A theory
b. A law
c. A prediction
d. A hypothesis
e. An experiment
8. In science, a theory should?
a. Be equated with knowledge
b. Be supported by a substantial body of evidence
c. Provide the ability to make correct predictions
d. All of the above
e. The second and third options only
9. Conducting research without a preconceived hypothesis is called? a. Discovery-based science
b. The scientific method
c. Hypothesis testing We also discuss several other topics like What are the four main types of components that make up the cell membrane?
Don't forget about the age old question of What are the different types of reinforcements?
d. A control experiment
e. None of the above
10. What is the purpose of using a control group in scientific experiments? a. A control group allows the researcher to practice the experiment first before actually conducting it
b. A researcher can compare the results in the experimental group and control group to determine if a single variable is causing a particular outcome in the
c. A control group provides the framework for the entire experiment so that the researcher can recall the procedures that should be conducted
d. A control group allows the researcher to conduct other experimental changes without disturbing the original experiment
e. All of the above
Chapter 1 Practice Problem Answers
1. Homeostasis (the organism has the bodily process of regulating temperature and keeping it balanced)
2. Evolution (as species evolve, they adapt and become more successful at life) 3. An ecosystem (while studying a population of organisms, she is studying an ecosystem since she’s observing their interactions with the environment)
4. The transmission of a gene conferring pathogenicity (the ability to cause disease) from one bacterial species to another (it’s transferring across bacterial species without being passed down through reproductive cell division)
5. Genus (the first term in a scientific name is always the organism’s genus) 6. Evolution (evolving from a common ancestor accounts for unity, evolving and adapting due to selective pressures account for our diversity)
7. A hypothesis (because it is a prediction, but it’s based on prior observation of the phenomenon)
8. All of the above (a theory should be backed by evidence, used to make valid predictions, and be accepted as knowledge)
9. Discovery-based science (observing and experimenting without a hypothesis to direct your research is discovery-based science)
10. A researcher can compare the results in the experimental group and control group to determine if a single variable is causing a particular outcome in the experimental group (a control group is contrasted with the experimental group to determine whether the one differing factor causes a difference in results between the two groups)
Chapter 2: The Chemical Basis of Life I: Atoms, Molecules, and Water Concepts to Know
● The structure of atoms and the electron shells
● Organization of the periodic table
● Atomic numbers and mass, and how mass is influenced by other isotopes ● The elements making up the most of biological life
● Difference between covalent and ionic bonds, and how hydrogen bonds and van der Waals dispersion forces play into molecule interactions
● How electronegativity affects polarity, and how molecular shape affects physical properties
● Components and goal of a chemical reaction
● Components of a solution
● The difference between, and how polarity affects, hydrophilic and hydrophobic molecules
● The meaning of molarity and how to find the molarity of a solution ● The three physical states of water, and how water has significant roles in living organisms
● How hydrogen and hydroxide ions contribute to the acid or alkaline concentration of solutions
● How buffers maintain homeostasis inside living organisms
1. What makes up the nucleus of an atom?
a. Protons and electrons
b. Protons and neutrons
c. Protons, neutrons, and electrons
d. Neutrons and electrons
2. Living organisms are composed mainly of which atoms?
a. Calcium, hydrogen, nitrogen, and oxygen
b. Carbon, hydrogen, nitrogen, and oxygen
c. Hydrogen, nitrogen, oxygen, and helium
d. Carbon, helium, nitrogen, and oxygen
e. Carbon, calcium, hydrogen, and oxygen
3. The ability of an atom to attract electrons in a bond with another atom is termed its? a. Hydrophobicity
e. Van der Waals dispersion force
4. Hydrogen bonds differ from covalent bonds in that?
a. Covalent bonds can form between any type of atom, but hydrogen bonds form only between H and O
b. Covalent bonds involve sharing of electrons, and hydrogen bonds involve the complete transfer of electrons
c. Covalent bonds result from equal sharing of electrons, but hydrogen bonds involve unequal sharing of electrons
d. Covalent bonds involve sharing of electrons between atoms, but hydrogen bonds are the result of weak attractions between a hydrogen atom of a polar molecule and an electronegative atom of another polar molecule
e. Covalent bonds are weak bonds that break easily, but hydrogen bonds are strong links between atoms that are not easily broken
5. During the formation of ions?
a. The atomic number of an anion and cation both increase by 1
b. An anion loses an electron and a cation gains an electron
c. An anion gains an electron and a cation loses an electron
d. An anion and cation both gain an electron
e. An anion and cation both lose an electron
6. Chemical reactions in living organisms?
a. May continue to completion if the products are removed
b. Often require a catalyst to speed up the process
c. Are in many cases reversible
d. Occur in liquid environments, such as water
e. May exhibit all of the above
7. Solutes that easily dissolve in water are said to be?
8. The molecular mass of glucose is about 180 g/mol. If 45g of glucose is dissolved into a final volume of 0.5L of water, what is the molarity of the solution?
9. The sum of the atomic masses of all the atoms in a molecule is its?
a. Atomic weight
c. Molecular mass
e. Molecular formula
10. Reactions in which water is used to break apart other molecules are known as what reactions?
Chapter 2 Practice Problem Answers
1. Protons and neutrons (Protons and neutrons are within the nucleus, electrons are located in the electron cloud surrounding the nucleus)
2. Carbon, hydrogen, nitrogen, and oxygen (These four are the most abundant elements in human life, calcium is a mineral element and if we were made of helium, we’d be floating right now)
3. Electronegativity (atoms with strong electronegativity seek out more electrons and want to bond with other atoms)
4. Covalent bonds involve sharing of electrons between atoms, but hydrogen bonds are the result of weak attractions between a hydrogen atom of a polar molecule and an electronegative atom of another polar molecule (covalent bonds involve sharing of electrons, hydrogen bonding can occur between hydrogen and any electronegative atom, not just oxygen)
5. An anion gains an electron and a cation loses an electron (anions are negative ions so they would have gained an electron, cations are positive so they would have lost one)
6. May exhibit all of the above (all of these are plausible situations for chemical reactions)
7. Hydrophilic (substances that like water will attract water molecules that break the bonds of the substance and dissolve it)
8. 0.5M (we must find the amount of moles per 1L of solution to find molarity, if the molecular mass is 180 g/mol and we only had 90g/mol (45 per .5L is 90 per 1L), we had ½ the amount of moles per 1L of solution, so we have 0.5 molarity)
9. Molecular mass (it’s good to know definitions)
10. Hydrolysis (hydrolysis is one of the properties of water, allowing it to break molecules into their individual components)
Chapter 3: The Chemical Basis of Life II: Organic Molecules
Concepts to Know
● The properties of carbon and how these affect the ways it bonds
● The different functional groups and what their properties are
● How hydrolysis and dehydration synthesis work to break apart or build up monomers and polymers
● The key functions of the four basic macromolecules
● The structures and functions of the monomers and polymers of carbohydrates ● The structures and functions of the monomers and polymers of lipids
● The structure of triglycerides and the difference between saturated and unsaturated fatty acids
● How and why phospholipids form bilayers
● The structure and purpose of steroids and waxes
● The functions of the different types of proteins
● The structure of amino acids and distinguishing the different amino acid side chains ● The hierarchy of protein structure (ie primary, secondary, tertiary, etc) ● The factors affecting protein structure and how proteins can be categorized into domains ● The structures that make up a nucleotide and how bases pair together
● The difference in structure and function of DNA and RNA
1. Which of the following is a common functional group found in organic molecules? a. A hydrocarbon
b. A ketone
c. An isomer
d. A carbon atom
e. An oxygen atom
2. Dehydration reactions may produce which of the following?
d. Amino acids
3. The versatility of carbon to serve as the backbone for a variety of molecules is due in part to?
a. The ability of carbon atoms to form four covalent bonds
b. The fact that carbon usually forms ionic bonds with many different atoms c. The abundance of carbon in the environment
d. The ability of carbon to form single, double, and triple bonds with many different types of atoms
e. Both a and d
4. Which of the following bonds is/are nonpolar?
d. Both a and b
e. Both a and c
5. ________ is a polysaccharide characterized by an unbranched arrangement and a high degree of hydrogen bonding.
6. All ________ contain four rings of carbon in their structure.
a. Fatty acids
7. The monomer of proteins are ________, and these are linked by polar covalent bonds commonly referred to as ________ bonds.
a. Nucleotides, peptide
b. Polypeptides, peptide
c. Dipeptides, amino
d. Amino acids, peptide
e. monosaccharides , glycosidic
8. A(n) ________ is a modular portion of a protein with a particular structure and function. a. Peptide bond
d. Amino acid
9. A DNA molecule contains 30% Guanine. What percentage is Adenine? a. 30%
e. None of the above
10. Random question
Chapter 3 Practice Problem Answers
1. A ketone
3. Both a and d
4. Both a and c
7. Amino acids, peptides
9. 20% (if guanine makes up 30%, so does cytosine because they form base pairs, therefore 40% is leftover and split between adenine and thymine)
10. Random answer
Chapter 4: Evolutionary Origin of Cells and their General Features Concepts to Know
● The four stages that led to the evolution of living cells
● The three hypotheses to how organic molecules first developed
● How protobionts and ribozymes led to the RNA world to the DNA/RNA/protein world ● The three key parameters of microscopy
● Light microscopes vs electron microscopes
● The four factors affecting cell structure and function
● The cell structures and basic functions of both prokaryotic and eukaryotic cells ● How the proteome affects the characteristics and functions of a cell ● Why surface area and volume are relevant to the shapes and sizes of cells
● The components of metabolism processes
● The functions of the cytosol, filaments of the cytoskeleton, and motor proteins ● The structures and functions of the nucleus and endomembrane system ● The structures and functions of the smooth ER vs rough ER, Golgi apparatus, lysosomes, vacuoles, and peroxisomes
● The structures and functions of the semiautonomous organelles
● Endosymbiosis theory and how evidence supports it
● How cells take part in different types of protein sorting
● The structure and function of the ECM in contrast to the structure and function of plants cell walls
● The systems biology view of how cell structures interact
● The differences between the structures and functions of prokaryotic cells, animal cells, and plant cells
1. The cell theory states that
a. All living things are composed of cells
b. Cells are the smallest units of living organisms
c. New cells come from preexisting cells by cell division
d. All of the above
e. A and b only
2. When using microscopes, resolution is what?
a. The ratio between the size of the image produced by the microscope and the actual size of the object
b. The degree to which a particular structure looks different from other structures around it
c. How well a structure takes up certain dyes
d. The ability to observe two adjacent objects as being distinct from each other e. The degree to which the image is magnified
3. A spherical cell has a radius of 34 micrometers. What is its surface area/volume ratio? a. 0.088
4. If a motor protein was held in place and a cytoskeletal filament was free to move, what kind of motion would occur when the motor protein was active?
a. The motor protein would walk along the filament
b. The filament would move
c. The filament would bend
d. All of the above would happen
e. Only b and c would happen
5. Each of the following is part of the endomembrane except what? a. The nuclear envelope
b. The endoplasmic reticulum
c. The Golgi apparatus
6. Which of the following is not a feature of the nucleus? a. Bounded by a double membrane
b. Nuclear envelope contains nuclear pores
c. Contains a nucleolus
d. Contains microtubules
e. Has chromosomes located in chromosome territories
7. Functions of the smooth endoplasmic reticulum include what? a. Detoxification of harmful organic molecules
b. Metabolism of carbohydrates
c. Protein sorting
d. All of the above
e. A and b only
8. The central vacuole in many plant cells is important for what? a. Storage
c. Structural support
d. All of the above
e. A and c only
9. Which of the following would not be found outside of animal cells? a. Collagen
c. Fibronectin and laminin
10. Which of the following observations would not be considered evidence for the endosymbiosis theory?
a. Mitochondria and chloroplasts have genomes that resemble smaller versions of bacterial genomes
b. Mitochondria, chloroplasts, and bacteria all divide by binary fission
c. Mitochondria, chloroplasts, and bacteria all have ribosomes
d. Mitochondria, chloroplasts, and bacteria all have similar sizes and shapes e. All of the above are considered evidence for the endosymbiosis theory Chapter 4 Practice Problem Answers
1. All of the above (the above options are all three ideas stated in the cell theory) 2. The ability to observe two adjacent objects as being distinct from each other (resolution is the clarity of the image)
3. 11.3 (use 4πr2 to find surface area, use 4πr3 to find volume, then divide) 4. The filament would move (the motor protein is fixed in place so it can’t walk along the filament, and the filament only bends if it’s also fixed in place)
5. Mitochondria (this is one of the semiautonomous organelles, but not part of the endomembrane system)
6. Contains microtubules (microtubules are part of the cytoskeleton in the cytosol) 7. A and b only (protein sorting is a function of the rough ER but not the smooth ER) 8. A and c only (the central vacuole stores materials and provides pressure from the
inside of the cell to give support, but photosynthesis takes place in the chloroplasts) 9. Actin (the other four are all structural or adhesive proteins part of the ECM, but actin makes up the protein filaments inside the cell)
10. Mitochondria, chloroplasts, and bacterial all have ribosomes (the other options show how the three are genetically or physically similar, but having ribosomes is a common trait for all cells)
Chapter 5: Membranes: The Interface Between Cells and their Environment Concepts to Know
● The concept of the phospholipid bilayer within the fluid-mosaic model ● The three different types of integral membrane proteins
● The fluidity of membranes and how its affected by changes in lipid composition ● The different ways phospholipids and proteins can move within membranes ● The meaning of selective permeability and the four methods of membrane transport ● How the process of osmosis works, and the two ways it can go wrong ● The functions of transport proteins
● Channels vs transporters
● Uniporters vs symporters vs antiporters
● How pumps and the two types of active transport relate to the electrochemical gradients and their functions
● Gap junctions vs plasmodesmata
● Cellular reasons for endocytosis and exocytosis
● The three methods of endocytosis
● The four types of anchoring junctions and how they contribute to cell interactions ● How CAMs contribute to the structure of anchoring junctions
● The purpose and function of tight junctions
1. Which of the following statements best describes the chemical composition of biological membranes?
a. Biological membranes are bilayers of proteins with associated lipids and carbohydrates
b. Biological membranes are composed of two layers; one layer of phospholipids and one layer of proteins
c. Biological membranes are bilayers of phospholipids with associated proteins and carbohydrates
d. Biological membranes are composed of equal numbers of phospholipids, proteins, and carbohydrates
e. Biological membranes are composed of lipids with proteins attached to the outer surface
2. Which of the following events in a biological membrane would not be energetically favorable and therefore not occur spontaneously?
a. The rotation of phospholipids
b. The lateral movement of phospholipids
c. The flip-flop of phospholipids to the opposite leaflet
d. The rotation of membrane proteins
e. The lateral movement of membrane proteins
3. Let’s suppose an insect, which doesn’t maintain a constant body temperature, was exposed to a shift in temperature from 60 degrees Fahrenheit to 80 degrees Fahrenheit. Which of the following types of membrane changes would be the most beneficial to help this animal cope with the temperature shift?
a. Increase in the number of double bonds in the nonpolar tails of phospholipids b. Increase in the length of the nonpolar tails of phospholipids
c. Decrease in the amount of cholesterol in the membrane
d. Decrease in the amount of carbohydrate attached to membrane proteins
e. Decrease in the amount of carbohydrate attached to phospholipids
4. Carbohydrates of the plasma membrane what?
a. Are bonded to a protein or lipid
b. Are located on the outer surface of the plasma membrane
c. Can function in cell surface recognition
d. All of the above
e. A and c only
5. Which of the following movements would not be an example of passive transport? a. The movement of water through aquaporin
b. The intercellular transport of molecules via gap junctions
c. The transport of Na+ and K+ via Na+/K+-ATPase
d. The diffusion of CO2 through a phospholipid bilayer
e. All of the above are examples of passive transport
6. The tendency for Na+ to move into the cell can be due to what?
a. The higher numbers of Na+ outside the cell, resulting in a chemical concentration gradient
b. The net negative charge inside the cell, attracting the positively charged Na+ c. The attractive force of K+ inside the cell, pulling Na+ into the cell d. All of the above
e. A and b only
7. Let’s suppose the solute concentration inside the cells of a plant is 0.3M and outside is 0.2M. If we assume that the solutes do not readily cross the membrane, which of the following statements best describes what will happen?
a. The plant cells will lose a lot of water, and the cells will crenate
b. The plant cells will lose a little water, and the cells will expand
c. The plant cell will take up a lot of water, and the cells will undergo osmotic lysis d. The plant cells will take up a little water, and the plasma membrane of the cells will slightly push against the cell wall
e. Both a and b are correct
8. What features of a membrane are a major contributor to its selective permeability? a. Phospholipid bilayers
b. Transport proteins
c. Glycolipids on the outer surface of the membrane
d. Peripheral membrane proteins
e. Both a and b
9. What is the process in which solutes are moved across a membrane against their concentration gradient?
a. Simple diffusion
b. Facilitated diffusion
d. Passive transport
e. Active transport
10. Large particles can be brought into the cell by what?
a. Facilitated diffusion
b. Active transport
e. All of the above
Chapter 5 Practice Problem Answers
1. Biological membranes are bilayers of phospholipids with associated proteins and carbohydrates (the membrane consists of a “phospholipid bilayer” with some proteins and carbohydrates embedded or attached throughout)
2. The flip-flop of phospholipids to the opposite leaflet (the lateral or rotational movement of phospholipids or proteins doesn’t result in a hydrophilic head having to cross a hydrophobic tail region like the flip-flop process does)
3. Increase in the length of nonpolar tails of phospholipids (the double bonds and cholesterol when warm will increase fluidity, the carbohydrates have no effect, but longer nonpolar tails increases stability and decreases fluidity)
4. All of the above (proteins can be embedded in the membrane or attached to the outside, and have a role in cell recognition)
5. The transport of Na+ and K+ via Na+/K+-ATPase (this transport is an example of secondary active transport, where the symporter is carrying one molecule to balance out concentration, but carrying another one against the concentration gradient)
6. A and b only (the positive force of K+ would not attract the also positive Na+ forces) 7. The plant cells will take up a little water, and the plasma membrane of the cells will slightly push against the cell walls (the slightly larger molarity inside the cell will
cause the cell to take in some water to dilute the inside solution, which will slightly expand the central vacuole)
8. Both a and b (the phospholipid bilayer is reluctant to open up and let water in, and the transport proteins decide what molecules to let in based on certain factors like size and shape)
9. Active transport (this is the method in which energy is needed to move solutes against their concentration gradients)
10. Phagocytosis (endocytosis methods would be used to take large molecules into the cell, and phagocytosis is the only type of endocytosis listed)