Biology- 1113 Exam 1 File
How many atoms are present in a single molecule of C₈H₁₀N₄O₂
24
Prokaryotice cells have
A cell membrane
A personal opinion on the effectiveness of a dietary supplement in preventing colds is an example of a/ an
Anecdote
Mediterranean gardeners' repeated replanting of seeds from wild mustard plants that showed unusually prolific flower bud and flower growth led to the creation of what modern cruciferous plants?
Broccoli and Cauliflower
The basic unit of life is the
Cell
What is the lowest level of biological organization that can perform all the activities required for life?
Cell- for example, pancreatic cell.
A scientist observed a chemical that changes to bright red in the presence of organic compounds containing nitrogen and phosphorous. To test this chemical, a set of test tubes is prepared, each tube containing a purified sample of one of the following organic compounds. The chemical is then added to each tube. The test tube containing ____ will always turn bright red.
Nucleic Acids
Which of the following organisms has a reproductive strategy that does NOT depend on eggs and sperm?
A bacterium
Imagine examining a cell using a light microscope; a prokaryote could be distinguished from a eukaryote by the absense of
A nucleus
The following figure shows the structural and space- filling models for stearic acid and oleic acid. Although the two fatty acids have the same number of carbon atoms, they have different three- dimensional configurations; oleic acid has a slight bend near the middle. The result is that
A pure sample of oleic acid would be more liquid than a pure sample of stearic acid.
Which of the following statements regarding cells is false?
All cells have a cell wall.
Which of the following observations strengthens the hypothesis that a common ancestor gave rise to all living organisms?
Almost all cells in all living organisms use DNA to direct their structure, function, and behavior.
Why are hypotheses never accepted as fact by scientists?
Alternative hypotheses might provide a better answer to the research question.
After adding a small amount of Solution A to Solution B, the pH of Solution B declines from 8 to 3. Solution A must contain
An acid.
In which of the following foods would the energy content be most directly connected to solar energy?
Apple
If life on Mars is fundamentally like life on Earth, its macromolecules will be based on which element?
Carbon
Which of the following statements regarding carbon is false?
Carbon has the ability to bond with up to six other atoms.
Which of the following sequences correctly represents the biological hierarchy of a multicellular organism?
Cells → Tissues → Organs → Organ Systems → Individuals.
The cell wall of plant cells is made of ___
Cellulose
When looking at a plant leaf through a light microscope, you notice small green organelles moving around in the cytoplasm of every cell. What organelle are you most likely seeing?
Chloroplasts
Which of the following is a lipid?
Cholesterol
Each of the following is a feature of all known living things EXCEPT
Consciousness
It has been observed that people with relatively high stress elvels get a relatviely high number of colds. This is an example of a(n)
Correlation
In organic compounds, carbon atoms are bound to each other by
Covalent bonds
The chemical reaction that represents the combustion of glucose is C₆H₁₂O₆ + O₂ → CO₂ + H₂O + E; the reactants are
C₆H₁₂O₆ + O₂
Which of the following statements is true?
Different eukaryotic cells contain different numbers and types of organelles, depending on the specific tasks they must perform.
Which of the following statements is a testable scientific hypothesis?
Eating fish reduces the likelihood of having a stroke.
A ribosome has internal cristae.
False
Covalent bonds contain ions
False
The brain is considered an organ because it is constructed from nerve cells.
False
When experimental data verify a prediction, the hypothesis is considered proven.
False
Ionic Bonds
Form between atoms that develop opposite charges.
Although the idea seems contradictory, science cannot prove a hypothesis to be true. Why?
Future experiments or discoveries may provide data that refute the hypothesis.
The part of the plasma membrane that is in contact with the external environment of the cell consists of _____ molecules.
Hydrophilic portions of the constituent.
An oil is a lipid that is ____ at room temperature.
Liquid
Developing a scientific understanding of a natural phenomenon typically begins by
Making an observation
The purpose of double- blind experiements is to
Minimize the effects of human bias on the results.
Your muscle cells need large amounts of ATP to function in the movement of your body. Which of the following organelles would you expect to be especially abundant in muscle cells?
Mitochondria
Microtubules are responsible for
Moving and positioning organelles inside the cell.
Which of the following combination of atoms would form ionic bonds?
Na⁺ and Cl⁻
In the following illustration, a positive ion is surrounded by water molecules. The water molecules orient as shown because the slightly _____ atoms in the water molecules are attracted to the positive charge of the ion.
Negative Oxygen
Which macromolecule has a sugar- phosphate backbone?
Nucleic Acid
You shake up a bottle of vinegar and oil dressing to mix it each time you use it. The reason you need to do this is that
Oil is hydrophoic and won't dissolve in vinegar, so the oil and vinegar separate over time.
The following figure shows two hydrogen atoms. How many covalent bonds will form between these two atoms?
One
This graph shows the 16- hour mortality rate resulting from exposing tilapia to different concentrations of the dinoflagellate Pfiesteria. If high mortality had occurred in the control group, we could conclude that
Pfiesteria was not the toxic agent responsible for the death of the fish.
What components of the plasma membrane of an animal cell would you find at its innermost surface, directly exposed to the cytoplasm?
Phospholipid heads and proteins.
Because the electrons in a qater molecule are shared unequally between hydrogen and oxygen, water is said to be
Polar
A molecule composed of amino acids is a
Protein
Enzymes are
Proteins
The scientific method cannot be used to evaluate untestable hypotheses. Which of the following types of questions are untestable?
Questions about topics other than the natural world.
The process of partial hydrogenation turns liquid plant lipids into semisolid lipids by
Removing double bonds and adding hydrogen to the fatty acid chains of plant lipids.
Using an electron microscope, you notice an organelle that consists of stacks of membranes with a "bumpy" texture and appears to be producing vesicles. This organelle is most likely
Rough Endoplasmic Reticulum.
Polysaccharides are polymers of
Sugars
When you place a piece of red meat on a hot barbeque, it slowly changes from soft to firm. Meat is primarily made of proteins. Which of the following might account for the change in texture during cooking?
The addition of heat causes proteins to denature and link together.
Which of the following statements about the biological hierarchy is true?
The biosphere includes all life forms and the places where they live.
How do the concentrations of H⁺ and OH⁻ compare to each other in an acidic solution?
The concentration of H⁺ is higher.
The inner membranes of both mitochondria and chloroplasts are folded into various arrangements. What is the advantage of having a folded membrane rather than a simple interior membrane that follows the same oval shape as the exterior membrane?
The folds allow for more surface are for the chemical reactions that occur across the inner membranes.
Lysosomes are organelles responsible for the breakdown of macromolecules. Why is it useful to have the lysosomal reactions compartmentalized, rather than allowing them to take place freely in the cytoplasm of the cell?
The lysosome's enzymes would break down cellular macromolecules that should remain intact.
A screen door allows breezes to enter and aromas to exit, but keeps out insects. Its function most resembles
The plasma membrane
The word "fluid" in the term fluid mosaic model refers to the fact that
The proteins within a membrane move around freely.
Which statement best describes the relationship between cell size (surface area, volume, and average width or radius) and cell function?
The rate of increase of volume exceeds that of surface area, causing membrane transport of nutrients and waste to become progressively inefficient as cell size increases.
Which of the following statements best summarizes structural differences between DNA and RNA?
The ribose sugar in DNA lacks an OH group that is present in RNA.
Which of the following statements about the scientific method is true?
The scientific method can help people make informed medical and environmental decisions.
In general, what makes one kind of amino acid different from other amino acids?
The side group
When phospholipids are added to water, they arrange themselves so that...
Their hydrophobic tails are on the inside of a lipid droplet.
Which of the following statements is true of chloroplasts?
They capture energy from sunlight.
The process of photosynthesis
Traps light energy in an energy carrier like ATP.
A microscope is used to obtain a magnified view of an object.
True
A molecule is constructed when two or more atoms become bonded to each other.
True
A solition with a pH of 7 is neither acidic nor basic.
True
DNA is an example of the molecular level of biological organization.
True
