Unit 1 chapters 1 & 3 Homework

Why is ATP necessary for active transport? ATP is a constituent of the electrochemical gradient. ATP is an important structural element of transport proteins. ATP provides energy to transfer material against its concentration gradient. ATP is in higher concentrations inside of the cell.

ATP provides energy to transfer material against its concentration gradient.

Which type of active transport protein uses one protein to pump two different molecules? Uniport Uniport, Antiport, and Symport Antiport and Symport Antiport Symport

Antiport and Symport

Which molecule shown in the animation, the square or the circle, is moving against its concentration gradient? Both the circle and the square The square The circle Neither; they are both moving with their respective concentration gradients.

Both the circle and the square

Vaccination came about when Jenner proved that infection with cowpox led to immunity for smallpox. How does vaccination with cowpox offer immunity to smallpox, a different and more serious disease? Vaccination with any poxvirus offers immunity to smallpox. Cowpox virus outcompetes smallpox virus. These two bacteria share a common ancestor. Cowpox and smallpox share very common protein structures.

Cowpox and smallpox share very common protein structures.

Dr. John Snow's investigation of the cholera epidemic of 1854 most closely matches which approach to epidemiology? View Available Hint(s) Analytical epidemiology Descriptive epidemiology Experimental epidemiology

Descriptive epidemiology

Experimental epidemiology:

Design and conduct a test of a hypothesis about a disease.

The tests for these uncommon pathogens are similar to the ones that have already been performed for the common viruses, but in this case, you will try to identify the DNA or proteins of specific viruses that are not often seen in clinics or hospitals in that area of the country. Each region of the country has certain viral pathogens that are spread throughout the human population that live in that area. When one of these viruses spreads to a new area, we consider it to be "emerging" in this new population of people. Some detective work and deductions will be required. By applying the scientific method, you can focus and refine your list of possible viral pathogens to experimentally test for. You'll begin your investigation by reviewing the patient's history and symptoms and formulating a hypothesis for possible causative agents. Based on what you know of the scientific method, what would you like to do next? Choose what your next step should be. Design and run some tests or experiments. Revise your list of possible viruses. Review the patient's charts again. Record your test results.

Design and run some tests or experiments.

Which of the following is part of the endomembrane system? View Available Hint(s) Golgi apparatus mitochondria ribosomes flagellum cytoskeleton

Golgi apparatus

Which of the following types of bacterial cells would have flagella located at only one end of the cell? Monotrichous and amphitrichous Peritrichous Amphitrichous Lophotrichous Lophotrichous and monotrichous Monotrichous

Lophotrichous and monotrichous

Analytical epidemiology:

Make a detailed investigation of data collected concerning a disease.

Which of the following types of bacterial cells would have only a single flagellum? Amphitrichous Monotrichous Lophotrichous Peritrichous Lophotrichous and monotrichous

Monotrichous

The scientific method is a four-step framework for the process of scientific investigation. Scientists have successfully applied the scientific method to address problems and questions for more than a century. The application of the scientific method has helped move science from philosophical debate to an understanding of the world around us based on reproducible facts and phenomena. Place the steps of the scientific method in the correct sequence from left to right. Observation leads to formulation of a question. Formulate a hypothesis to address a question. Design and conduct experiments. Scientist decides to accept, reject or modify a hypothesis.

Observation leads to formulation of a question. Formulate a hypothesis to address a question. Design and conduct experiments. Scientist decides to accept, reject or modify a hypothesis.

Match the field of epidemiology with the step of the scientific method it most closely fits.

Observation leads to formulation of a question: Descriptive epidemiology Formulation of a hypothesis to address a question: Experimental epidemiology Scientist decides to accept, reject, or modify a hypothesis: Analytical epidemilogy

Dr. John Snow was a physician in London who was interested in understanding cholera. Based on his observations he believed water was somehow involved. In 1854 there was a serious outbreak of cholera in London during which hundreds of people became ill and died. Dr. Snow visited patients and provided what treatment he could. While in the patients' homes he asked questions of the family about their activities prior to the patient becoming ill. Based on the answers he received he concluded one water well in London was the source of the cholera cases. Drag the description of Dr. Snow actions or activities to the step of the scientific method it most closely fits.

Observation leads to formulation of a question: Observations suggest to Dr. Snow water is involved in cholera. Formulation of a hypothesis to address a question: Observations suggest to Dr. Snow water is involved in cholera. Design and conduct experiments: Not Applicable Collect and analyze data: Dr. Snow collects information about patients' activities prior to becoming ill. Scientist decides to accept, reject or modify a hypothesis: Dr. Snow concludes a specific well is the source of the cholera cases

"Uncommon" or "emerging" pathogens are ones that are rarely seen in a clinical setting or are new to a geographic area. As a scientist, you will need to follow a logical pattern to determine what the unknown virus is. This logical process is one that all scientists are familiar with the scientific method. The scientific method is a process of determining what natural phenomenon is to be studied and developing a series of experiments to determine what is occurring. Order the steps of the scientific method as a virologist would implement them on the job. Put the following steps of the scientific method in order (from left to right) that should be followed to identify the virus that is causing this disease. Observe a natural phenomenon or reaction. Devise an explanation of what you have observed. Experiment to support or refute your explanation. Record the results of your experiments. Determine whether your results support or refute your explanation. Decide whether you need to rewrite your explanation or it has with stoodtesting.

Observe a natural phenomenon or reaction. Devise an explanation of what you have observed. Experiment to support or refute your explanation. Record the results of your experiments. Determine whether your results support or refute your explanation. Decide whether you need to rewrite your explanation or it has with stoodtesting.

Descriptive epidemiology:

Observe and collect data concerning a disease.

Smallpox is the only disease to date that has been completely eradicated from the human population. This is due to the collective efforts of researchers, clinicians, and the World Health Organization. The history of this eradication is important and may lead to the eradication of other diseases that plague humans. Order the events:

Patients variolized against smallpox. Jenner observes milkmaids have immunity to smallpox. Jenner develops cowpox vaccine. Vaccinia virus discovered in vaccines. Campaign to eradicate smallpox begins.

Since smallpox has been eradicated, the world has set its eyes on other diseases. However, this task it not an easy one. It will never be possible to eradicate every disease in the world, but it may be possible to knock out a few more. The World Health Organization is searching for another disease to eradicate. Which of the following will be the most likely candidate? Polio only infects humans and is almost always symptomatic. Gonorrhea only infects humans, and it is often asymptomatic. Influenza virus infects humans as well as birds and swine, and it is almost always symptomatic. There are no more likely candidates; smallpox required a great deal of luck.

Polio only infects humans and is almost always symptomatic.

All viruses are different. They have different shapes, sizes, and methods for infection. Smallpox virus belongs to a family of viruses known as the poxviruses. Like you and your family, they share similarities, but they are also different in their own special way. Place the correct characteristics for the smallpox virus in the bin marked "Smallpox virus." Place all other characteristics not related to the smallpox virus in the bin marked "influenzavirus."

Smallpox virus: DNA virus, Replicates in cytoplasm, large virus, complex Influenzavirus: Simple, Replicates in nucleus, RNA virus, small virus

Which type of active transport protein moves two molecules into the cell at the same time? Uniport Antiport Symport Antiport and Symport Uniport, Symport, and Antiport

Symport

A patient is infected with Gram-negative bacteria and is experiencing only mild symptoms. When the patient is given an antibiotic causing lysis of the bacterial cells, he suddenly experiences an increase in inflammation and fever, as well as the formation of blood clots. What explanation best describes what happened? The lysis of the cells releases lipid A from the lipopolysaccharide layer. The lysis of the cells releases NAG and NAM from the cell wall. The antibiotic is toxic and is affecting the patient adversely. Any part of the bacterial cell wall released during lysis is seen as foreign and thereby elicits a severe immune response by the body's immune system.

The lysis of the cells releases lipid A from the lipopolysaccharide layer.

What role do the teichoic acids play within the cell wall of Gram-positive bacteria? View Available Hint(s) They serve as pores allowing the passage of ions, nutrients, and amino acids into the cell. They serve as adhesins, allowing bacteria to bind to one another. They serve to stabilize the cell wall and hold it in place. They act as crossbridges, holding the peptides and sugar molecules together.

They serve to stabilize the cell wall and hold it in place.

For viruses to thrive on Earth, they need to keep moving from host to host. For this reason, a virus must use techniques for infecting new hosts and then spreading to others. Smallpox is very capable of spreading from one person to another. Below is a list of ways viruses can spread from one person to another. Place the ways in which smallpox most frequently spreads into the bin labeled "Most Frequent Transmission," place less frequent ways to transmit smallpox in the bin labeled "Less Frequent Transmission," and place all other methods in the bin labeled "Transmission Unlikely."

Transmission Unlikely: Eating undercooked beef, Drinking unchlorinated water, sexual intercourse Less frequent Transmission: Soiled sheets, shaking hands Most frequent Transmission: Coughing, sneezing

Which transport protein employs transporters that move molecules only in one direction? Antiport Uniport, Antiport, and Symport Uniport and Antiport Uniport and Symport Symport Uniport

Uniport and Symport

Koch's work involving anthrax was significant because it was the first time __________. View Available Hint(s) anthrax had been discovered in humans a bacterium had been proven to cause a disease bacteria had been grown in a laboratory bacteria had been seen in a microscope

a bacterium had been proven to cause a disease

The peptidoglycan cell wall of bacteria is most analogous to _____. a sugary candy shell a rain coat a chain-link fence an impenetrable brick wall

a chain-link fence

Peptidoglycans are composed of sugars and _____. View Available Hint(s) lipids teichoic acids nucleic acids amino acids

amino acids

The structural framework in a cell is the cytoskeleton. plasma membrane. endomembrane system. endoplasmic reticulum (ER). extracellular matrix.

cytoskeleton.

You have successfully completed the experiments and analyzed your results. Your analysis has allowed you to refine you hypothesis and remove all but one virus strain from your list of possible causative agents. With your success at identifying the viral pathogen, you will now need to begin the long process of characterization, the studying of all aspects of an organism to determine whether this virus is truly new or has been isolated and identified before. The characterization will begin with studying the genome of this pathogen. Sequencing machines will determine the order of the nucleic acids that make up the viral genome, and computers will be able to analyze this sequence to determine the genes available for this virus. What is the area of biology that studies the nucleic acid makeup of an organism? Pick the area of biology that studies DNA and chromosomes. molecular biology genetics genealogy biochemistry

genetics

Spallanzani's experiments concerning spontaneous generation were NOT universally accepted because __________. View Available Hint(s) he did not heat his infusion flasks long enough he did not know which bacteria were growing in his flasks he eliminated air from his flasks by sealing them he did not give proper credit to Needham for his experiments

he eliminated air from his flasks by sealing them

Which of the following organelles breaks down worn-out organelles? lysosomes smooth endoplasmic reticulum (ER) rough endoplasmic reticulum (ER) mitochondria Golgi apparatus

lysosomes

What carries instructions for making proteins from the nucleus into the cytoplasm? View Available Hint(s) DNA Rough ER ATP mRNA ribosomes

mRNA

Where in a cell is ATP made? View Available Hint(s) chloroplasts mitochondria lysosomes nucleus ribosomes

mitochondria

Where is the genetic information of the cell stored? rough endoplasmic reticulum (ER) smooth endoplasmic reticulum (ER) Golgi apparatus lysosomes nucleus

nucleus

The region between the outer and inner membranes of a Gram-negative bacterial cell is known as the __________, and it is the location of enzymes that assemble peptidoglycan. View Available Hint(s) periplasmic space cytoplasm intramembranous space lipopolysaccharide layer

periplasmic space

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell? extracellular matrix nuclear envelope cytoskeleton endomembrane system plasma membrane

plasma membrane

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by View Available Hint(s) the extracellular matrix. mitochondria. the Golgi apparatus. ribosomes. the cytoskeleton.

ribosomes.

Where are lipids made in the cell? rough endoplasmic reticulum (ER) ribosomes smooth endoplasmic reticulum (ER) Golgi apparatus mitochondria

smooth endoplasmic reticulum (ER)

One chain of alternating NAGs and NAMs is connected to another chain via _____. teichoic acids enzymes tetrapeptides lipids

tetrapeptides

Tumbles occur when the flagella undulate. the flagella rotate clockwise. the flagella stop rotating. the flagella rotate counterclockwise.

the flagella rotate clockwise.

Peritrichous bacteria make a run when the flagella turn clockwise and separate. the flagella turn counterclockwise and become bundled. the flagella turn counterclockwise and separate. the flagella turn clockwise and become bundled.

the flagella turn counterclockwise and become bundled.

One of the main differences between a Gram-positive and a Gram-negative bacterial cell wall is that the peptidoglycan portion of a Gram-positive cell wall is _____ as compared to a Gram-negative cell wall. positively charged thicker composed of a greater percentage of NAGs than NAMs more lipid rich

thicker

Within the peptidoglycan layer, the crossbridges that connect the chains of alternating sugar molecules extend between _____. an N-acetylmuramic acid and an N-acetylglucosamine two N-acetylglucosamine molecules two glucose molecules two N-acetylmuramic acid molecules

two N-acetylmuramic acid molecules

In the late 1800s, a researcher by the name of Robert Koch developed a series of postulates (guidelines) that can be used to prove that a given pathogen is the true cause of a disease.Koch's Postulates1. The suspected causative agent must be found in every case of the disease and be absent from healthy hosts.2. The agent must be isolated and grown outside the host.3. When the agent is introduced to a healthy, susceptible host, the host must get the disease.4. The same agent must be found in the diseased experimental host.Which of the following steps does NOT follow one of Koch's postulates? Pick step that does NOT follow the postulates. You collect a throat swab from a family member who has also become sick. A mouse that was exposed to a potential viral pathogen has died and you are able to isolate the virus from the liver of the mouse. You give a patient an antibiotic to treat an infection. You are able to isolate a pathogenic bacterium from someone with a new type of pharyngitis.

You give a patient an antibiotic to treat an infection.