Question 1

Which three characteristics best support the rapid evolution of prokaryotic populations?

Accepted Answer

A large population provides more opportunities for mutations and the potential for natural selection to act upon. Rapid growth allows for faster reproduction and more generations to evolve. The ability to exchange DNA through horizontal gene transfer allows for sharing of beneficial traits among different prokaryotic populations.

Question 2

Which statement is NOT true about mutations?

Accepted Answer

Mutations can occur in both sexual and asexual reproduction. Therefore, statement C is not true.

Question 3

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell.Nevertheless, mitochondria cannot function for long when isolated from the cell because they are

Accepted Answer

Mitochondria are endosymbionts, which means they have a symbiotic relationship with their host cell, being originally prokaryotic but finally incorporated into eukaryotic cells. Mitochondria contain their own genome (mtDNA), which can replicate independently of the cell's nuclear DNA. However, they cannot function for long when isolated from the cell because they rely on the host cell for many crucial functions. Therefore, choices A, B, and D are incorrect.

Question 4

What unit of length would you generally use to measure a typical plant or animal cell?

Accepted Answer

The best unit of length to measure a typical plant or animal cell is the micrometer as it is the most commonly used unit for measuring small objects like cells. A micrometer is one millionth of a meter or 0.001 millimeters. It is also known as a micron. The size of a typical plant or animal cell ranges from 10-30 micrometers.

Question 5

Select the option that BEST finishes the following statement: Evolution is a process

Accepted Answer

Evolution is fundamentally driven by mutation and natural selection, which are key principles in understanding how species adapt and evolve over time.

Question 6

The __________ __________ is made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum.

Accepted Answer

The description given matches the structure of the nuclear envelope, which consists of two concentric membranes and is continuous with the endoplasmic reticulum membrane. The plasma membrane and Golgi network have different structures and functions, while mitochondria have a single membrane.

Question 7

The central dogma provides a framework for thinking about how genetic information is copied and used to produce structural and catalytic components of the cell.From the choices below, select the order of biochemical processes that best correlates with the tenets of the central dogma.

Accepted Answer

The central dogma states that genetic information flows from DNA to RNA to proteins. Replication is the process by which DNA is copied to produce an identical copy. Transcription is the process by which DNA is used as a template to synthesize RNA, and translation is the process by which RNA is used to synthesize proteins. Therefore, the order of biochemical processes that best correlates with the central dogma is: replication (copying of DNA), transcription (making an RNA copy of DNA), and translation (using the RNA to synthesize proteins). Choice A correctly follows this order.

Question 8

The mitochondrial proteins found in the inner membrane are involved in the conversion of ADP to ATP, a source of energy for the cell.This process consumes which of the following substances?

Accepted Answer

The process of converting ADP to ATP, known as oxidative phosphorylation, requires oxygen as a final electron acceptor in the electron transport chain. Therefore, the consumption of oxygen is necessary for the production of ATP in the mitochondria. Nitrogen, sulfur, and carbon dioxide are not involved in this process.

Question 9

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

Accepted Answer

The process of change and selection over the course of many generations is the basis of evolution. Mutation, heredity, and reproduction are all important factors in evolution, but they alone do not fully encompass the concept.

Question 10

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell.Which answer below indicates a correct pairing of the material "burned" and the form of energy produced during cellular respiration?

Accepted Answer

Cellular respiration uses sugar as the material "burned" and produces ATP, which is the chemical energy used by the cell. Fat can also be a source of energy during cellular respiration, but it is not the primary material "burned" and it does not directly produce ADP or protein.

Question 11

Prokaryotic cells do not possess

Accepted Answer

Prokaryotic cells lack a nucleus, which is a defining characteristic that differentiates them from eukaryotic cells.

Question 12

Which of the following organelles has both an outer and an inner membrane?

Accepted Answer

The mitochondrion has both an outer and an inner membrane, with the inner membrane having many folds called cristae. This organelle is responsible for cellular respiration and producing ATP.

Question 13

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.

Accepted Answer

Proteins are made from 20 different amino acids, which are linked together in different sequences to make different proteins with different functions. Nucleotides make up DNA and RNA, sugars make up carbohydrates, and fatty acids make up lipids.

Question 14

The nucleus, an organelle found in eukaryotic cells, confines the __________, keeping them separated from other components of the cell.

Accepted Answer

The chromosomes, which contain the genetic material of the cell, are confined within the nucleus, keeping them separated from other components of the cell. Lysosomes, peroxisomes, and ribosomes are not confined to the nucleus.

Question 15

Living systems are incredibly diverse in size, shape, environment, and behavior.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?

Accepted Answer

The smallest living unit is the cell, which is the basic unit of life and contains all the necessary components to carry out life processes. DNA, organelles, and proteins are important components of cells, but are not considered to be complete living units on their own.

Question 16

Select the option that correctly finishes the following statement: A cell's genome

Accepted Answer

A cell's genome refers to all of its DNA, including both coding and non-coding regions. Option A is incorrect as many genes do not code for proteins. Option C is incorrect as the genome itself does not change, although which parts are expressed may change. Option D is incorrect as the genome is set at conception and does not change during embryonic development.

Question 17

What is the smallest distance two points can be separated and still resolved using light microscopy?

Accepted Answer

The smallest distance two points can be separated and still resolved using light microscopy is approximately 0.2 μm (200 nm), due to the diffraction limit of light.

Question 18

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 fluorescent microscope is still limited by the __________ of visible light.

Accepted Answer

The resolving power of a microscope is limited by wavelength. This means that the smallest distance between two points that can be distinguished is proportional to the wavelength of the light being used. In the case of fluorescence microscopy, although targeted fluorescent dyes or modified fluorescent proteins allow for better visualization, the resolving power is still limited by the wavelength of visible light.

Question 19

Which statement is NOT true about the events/conclusions from studies during the mid-1800s surrounding the discovery of cells?

Accepted Answer

The conclusion that new cells can form spontaneously from the remnants of ruptured cells was actually disproven during the mid-1800s by experiments done by Louis Pasteur and others. This was known as the theory of spontaneous generation, which was eventually replaced by the principle of biogenesis (that living organisms only arise from other living organisms).

Question 20

The world of prokaryotes is divided into two domains (bacteria and archaea), each as different from each other as from eukaryotes.Select the observable characteristic that BEST separates archaea from bacteria.

Accepted Answer

Both bacteria and archaea can metabolize inorganic substances, thrive in anaerobic conditions, and be photosynthetic organisms. However, archaea are known for being able to survive in extremely harsh environments such as high temperatures, extreme acidity or alkalinity, and high salinity. This is the characteristic that best separates archaea from bacteria.

Quiz 1: Cells: The Fundamental Units of Life