PCB 3023 Final Exam well answered
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Living systems are incredibly diverse in size, shape, environment, and behaviours. It is estimated that
there are between 10 million and 100 million different species. Despite this wide variety of
organisms, it remains difficult to define what it means to say something is alive. Which of the
following can be described as the smallest living unit?
(a) DNA
(b) cell
(c) organelle
(d) protein - correct answer cell
The flow of genetic information is controlled by a series of biochemical reactions that result in the
production of proteins, each with its own specific order of amino acids. Choose the correct series of
biochemical reactions from the options presented here.
(a) replication, transcription, translation
(b) replication, translation, transcription
(c) translation, transcription, replication
(d) translation, replication, transcription - correct answer (a) replication, transcription, translation
Proteins are important architectural and catalytic components within the cell, helping to determine
its chemistry, its shape, and its ability to respond to changes in the environment. Remarkably, all of
the different proteins in a cell are made from the same 20 __________. By linking them in different
sequences, the cell can make protein molecules with different conformations and surface
chemistries, and therefore different functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - correct answer (c)amino acids.
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less fit for survival than their
parents.
,(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that are as fit for survival as their
parents are. - correct answer (c) A mutation is a result of sexual reproduction.
Changes in DNA sequence from one generation to the next may result in offspring that are altered in
fitness compared with their parents. The process of change and selection over the course of many
generations is the basis of __________.
(a) mutation.
(b) evolution.
(c) heredity.
(d) reproduction. - correct answer (b) evolution
Select the option that best finishes the following statement: "Evolution is a process __________."
(a) that can be understood based on the principles of mutation and selection.
(b) that results from repeated cycles of adaptation over billions of years.
(c) by which all present-day cells arose from 4-5 different ancestral cells.
(d) that requires hundreds of thousands of years. - correct answer (a) that can be understood based
on the principles of mutation and selection.
Select the option that correctly finishes the following statement: "A cell's genome
_________________."
(a) is defined as all the genes being used to make protein.
(b) contains all of a cell's DNA.
(c) constantly changes, depending upon the cell's environment.
(d) is altered during embryonic development. - correct answer (b) contains all of a cell's DNA.
Which statement is NOT true about the events/conclusions from studies during the mid-1800s
surrounding the discovery of cells?
(a) Cells came to be known as the smallest universal building block of living organisms.
(b) Scientists came to the conclusion that new cells can form spontaneously from the remnants of
ruptured cells.
(c) Light microscopy was essential in demonstrating the commonalities between plant and animal
tissues.
, (d) New cells arise from the growth and division of previously existing cells. - correct answer (b)
Scientists came to the conclusion that new cells can form spontaneously from the remnants of
ruptured cells.
What unit of length would you generally use to measure a typical plant or animal cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers - correct answer (d) micrometers
Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard
fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though
fluorescence permits better visualization, the resolving power is essentially the same as that of a
standard light microscope because the resolving power of a microscope is limited by the __________
of light.
(a) absorption
(b) intensity
(c) filtering
(d) wavelength - correct answer (d) wavelength
What is the smallest distance two points can be separated and still resolved using light microscopy?
(a) 20 nm
(b) 0.2 μm
(c) 2 μm
(d) 200 μm - correct answer (b) 0.2 μm
By definition, prokaryotic cells do not possess __________.
(a) a nucleus.
(b) replication machinery.
(c) ribosomes.
(d) membrane bilayers. - correct answer (a) a nucleus.
already passed
Living systems are incredibly diverse in size, shape, environment, and behaviours. It is estimated that
there are between 10 million and 100 million different species. Despite this wide variety of
organisms, it remains difficult to define what it means to say something is alive. Which of the
following can be described as the smallest living unit?
(a) DNA
(b) cell
(c) organelle
(d) protein - correct answer cell
The flow of genetic information is controlled by a series of biochemical reactions that result in the
production of proteins, each with its own specific order of amino acids. Choose the correct series of
biochemical reactions from the options presented here.
(a) replication, transcription, translation
(b) replication, translation, transcription
(c) translation, transcription, replication
(d) translation, replication, transcription - correct answer (a) replication, transcription, translation
Proteins are important architectural and catalytic components within the cell, helping to determine
its chemistry, its shape, and its ability to respond to changes in the environment. Remarkably, all of
the different proteins in a cell are made from the same 20 __________. By linking them in different
sequences, the cell can make protein molecules with different conformations and surface
chemistries, and therefore different functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - correct answer (c)amino acids.
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less fit for survival than their
parents.
,(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that are as fit for survival as their
parents are. - correct answer (c) A mutation is a result of sexual reproduction.
Changes in DNA sequence from one generation to the next may result in offspring that are altered in
fitness compared with their parents. The process of change and selection over the course of many
generations is the basis of __________.
(a) mutation.
(b) evolution.
(c) heredity.
(d) reproduction. - correct answer (b) evolution
Select the option that best finishes the following statement: "Evolution is a process __________."
(a) that can be understood based on the principles of mutation and selection.
(b) that results from repeated cycles of adaptation over billions of years.
(c) by which all present-day cells arose from 4-5 different ancestral cells.
(d) that requires hundreds of thousands of years. - correct answer (a) that can be understood based
on the principles of mutation and selection.
Select the option that correctly finishes the following statement: "A cell's genome
_________________."
(a) is defined as all the genes being used to make protein.
(b) contains all of a cell's DNA.
(c) constantly changes, depending upon the cell's environment.
(d) is altered during embryonic development. - correct answer (b) contains all of a cell's DNA.
Which statement is NOT true about the events/conclusions from studies during the mid-1800s
surrounding the discovery of cells?
(a) Cells came to be known as the smallest universal building block of living organisms.
(b) Scientists came to the conclusion that new cells can form spontaneously from the remnants of
ruptured cells.
(c) Light microscopy was essential in demonstrating the commonalities between plant and animal
tissues.
, (d) New cells arise from the growth and division of previously existing cells. - correct answer (b)
Scientists came to the conclusion that new cells can form spontaneously from the remnants of
ruptured cells.
What unit of length would you generally use to measure a typical plant or animal cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers - correct answer (d) micrometers
Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard
fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though
fluorescence permits better visualization, the resolving power is essentially the same as that of a
standard light microscope because the resolving power of a microscope is limited by the __________
of light.
(a) absorption
(b) intensity
(c) filtering
(d) wavelength - correct answer (d) wavelength
What is the smallest distance two points can be separated and still resolved using light microscopy?
(a) 20 nm
(b) 0.2 μm
(c) 2 μm
(d) 200 μm - correct answer (b) 0.2 μm
By definition, prokaryotic cells do not possess __________.
(a) a nucleus.
(b) replication machinery.
(c) ribosomes.
(d) membrane bilayers. - correct answer (a) a nucleus.
