exam 1 Flashcards
The study of how organisms interact with each other and with their physical environment in nature is called:
ecology
In some experiments, several identical groups are set up, keeping conditions similar among them. In the _____ group, a change is deliberately introduced. In the _____ group, this change is not introduced. In this way, the researcher can determine if the change has an effect.
test; control
A major difference between eukaryotic cells and prokaryotic cells is that:
eukaryotic cells have a nucleus and prokaryotic cells do not.
Imagine walking through a tropical rainforest. You notice that there are different types of trees, birds, insects, and other organisms. A few weeks later you are taking a walk through the desert and notice that the trees, birds, insects, and other organisms are different than those you saw in the rainforest. Which of the following statements BEST explains the differences between each of these ecological systems?
Organisms in each ecological system have evolved in that system and have adaptations suited for that environment.
Which of the following sequences correctly represents the scientific approach to learning?
observation → question → hypothesis → experiment
The feature of an experiment that is changed from one treatment to the next is referred to as a(n):
variable
Measuring its costs and benefits in terms of energy spent and/or gained, mutualism:
results in gain for both individuals.
Humans have affected life on Earth in which of the following ways?
Many species have been driven to extinction.
We are contributing to the carbon, nitrogen, and other biogeochemical cycles.
We have altered or destroyed the habitat of many species.
Some species have actually benefited from human activities.
All organisms use which of the following molecules to carry out metabolic reactions?
ATP
Translation is the process by which:
proteins are synthesized from RNA molecules.
Observations allow scientists to draw tentative explanations called hypotheses.
true
When small molecules are linked together to form larger molecules, the increase in entropy typically comes from:
heat
_____ is NOT a domain of life
Protists
Ecological relationships reflect the _____ traits of organisms in nature.
behavioral, physiological, and biomechanical
Imagine that you are standing in a field and you see a group of butterflies. You notice an individual that looks significantly different from the other butterflies in the population. This difference allows the butterfly to escape predation more efficiently than other butterflies in the population. How might this trait have arisen in the individual?
There was a random mutation in a gene that led to differences in the ability to escape predation.
Which of the following is an example of the first law of thermodynamics in action?
Light energy is transformed into chemical energy during photosynthesis.
The designation of a magnesium ion as Mg2+ indicates an atom that has:
lost two electrons and is positively charged.
Isomers are defined as:
molecules with the same chemical formula but different structures.
The ability of atoms to attract electrons is referred to as:
electronegativity.
A pair of shared valence electrons is referred to as a(n):
covalent bond
The linkage of one amino acid to another amino acid in a protein is referred to as a(n):
peptide bond.
Triacylglycerols are used primarily for:
energy storage
Which of the following correctly lists the simple molecules that were generated by Stanly Miller and others in experiments that attempted to replicate the conditions on Earth under which life may have originated?
simple sugars, amino acids, lipids, and nucleotides
Which one of the following elements is found in every organic molecule?
carbon
Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distinguishes them from carbohydrates?
ability to catalyze biochemical reactions
Miller and Urey’s initial simulation resulted in the formation of which one of the following?
amino acids
Which one of the following represents the pH of a solution with the HIGHEST concentration of hydrogen ions?
1.0
_____ are the subunits of nucleic acids, and _____ are the subunits of proteins.
Nucleotides; amino acids
Which statement BEST describes an effect of the low density of frozen water in a lake?
When water in a lake freezes, it floats, providing insulation for organisms below the ice.
How many electron orbitals does a carbon atom possess?
5
Which one of the following elements would MOST likely have bonding properties similar to nitrogen (N)?
phosphorus (P)
14C is an isotope of carbon that possesses:
6 protons, 8 neutrons, and 6 electrons.
The idea that, when life originated on Earth, a macromolecule other than DNA served the role of information storage and that this same macromolecule carried out catalysis is called the _____ hypothesis.
RNA world
Deoxyribonucleic acid is used for:
storage of information
transmission of information.
Which of the following is true about the structure of a double-stranded DNA molecule?
The diameter of a DNA molecule is the same along its entire length due to the specific complementary base pairing of the DNA nucleotides.
The base uracil pairs with:
adenine.
An organism’s genomic DNA is analyzed and found to contain 22% thymine. What percentage of that organism’s DNA is guanine?
28%
The central dogma of molecular biology states that information flows from:
DNA to RNA to protein.
A single unit of heredity that contains the information for an individual protein is referred to as a
gene
Translation is the process by which:
ribosomes synthesize protein from information in an RNA molecule.
Which of the following DNA molecules would be more stable under conditions of increasing temperature?
A DNA molecule that has more guanine and cytosine nucleotides
One function of the spliceosome is to
recognize the beginning and end of the exons
The type of RNA that physically interacts with a ribosome, providing the sequence information for a specific protein, is abbreviated:
mRNA
Which one of the following is LEAST likely to be found in a nucleotide?
a side chain
Which one of the following statements about RNA is CORRECT?
RNA uses the same purine bases as DNA.
In eukaryotes, activator proteins bind to _____; generalized transcription factors bind to _____.
enhancers; promoters
When a mixture of debris from killed virulent bacteria and live nonvirulent bacteria are injected into mice:
the mice are killed because the nonvirulent bacteria are transformed into virulent bacteria.
Which one of the following RNA types is MOST abundant in mammalian cells?
rRNA
Which one of the following represents an actual Watson-Crick base pair with the LARGEST number of hydrogen bonds?
cytosine and guanine
Where does the energy come from to add a uracil to the 3’ end of a transcript?
the hydrolysis of pyrophosphate from the incoming UTP molecule
In a nucleotide, the phosphate is attached to the _____ carbon of the sugar, and the base is attached to the _____ carbon of the sugar.
5’; 1’
Which type of protein does DNA wrap around so that it can be packaged in a cell?
helps prevent rapid breakdown of the messenger RNA.
A region of a protein that folds in a particular way, and that carries out a specific function, is referred to as a folding
domain
