In the early days of germ theory, contagious diseases were thought to be caused only by fungi or bacteria. In the 1890s, Dmitri Ivanovski filtered extracts from diseased tobacco plants and discovered that the disease could be transmitted to new plants through the filtrate. He hypothesized that something smaller than bacteria or fungi was responsible for the transmission of the disease. Which best explains how Ivanovski's work led to a change in the germ theory? He tried to promote his hypothesis as a law. He used a new experimental method to test his hypothesis. He used a more powerful bacterial strain than other scientists had. He obtained results that confirmed what other scientists were thinking.

Answers

Answer 1

Answer:

He used a new experimental method to test his hypothesis.

Explanation:

Dmitri Ivanovski, a Russian microbiologist who was born in the year 1864 and died in 1920. He was the scientist who initiated the discovery of viruses as a pathogenic microorganism. He worked to discover the cause of mosaic disease in tobacco plant and he hypothesized that that something smaller than bacteria or fungi, as early believed, was responsible for the transmission of the disease.

In order to test his hypothesis, he passed a solution containing the causative agent of the disease, which he prepared from the infected plant leaves, through a filter known as Chamberland filter. He was able to discover that the filtrate still contained microbial pathogens that can infect more tobacco plants, confirming his hypothesis that something smaller than fungi or bacteria is responsible for the tobacco mosaic infection.

Hence, to test out his hypothesis, Ivanovski in the 1890's used a new experimental method i.e. CHAMBERLAND FILTER method.


Related Questions

What is the difference between functional anatomy and gross anatomy? (A).Functional anatomy studies the structure of organ systems; gross anatomy studies the function of organ systems. (B)Functional anatomy studies the function of the organ and organ systems; gross anatomy studies the large-scale structure of the human body. (C)Functional anatomy studies the function of organ systems; gross anatomy studies the external features of the body.

Answers

Answer:

(B)Functional anatomy studies the function of the organ and organ systems; gross anatomy studies the large-scale structure of the human body

Explanation:

Anatomy is the study of the structure of the body. Anatomical studies is important in having a better understanding of the structural characteristics and composition of a body. However, anatomy is divided into sections.

One of those parts of anatomy is GROSS anatomy, which is the study of the structures that are visible to the human eye. Hence, it is also called Macroscopic anatomy or large-scale anatomy. Functional anatomy, on the other hand, is the study of the body's structure based on their function. It is termed morphophysiology because it studies the function of organs and organ systems.

Answer:

Functional anatomy studies the structure of organ systems  gross anatomy studies the function of organ systems

Explanation:

Each DNA molecule resulting from replication has one original strand and one new strand. This also known as _________________________replication of DNA.

Answers

Answer: if ur learning about mitosis it’s prophase

Explanation:

Answer:

it is synthesis phase

Explanation:

because during synthesis phase, the cell makes an entire copy of DNA, referred to as DNA replication.

What habitat is home to 50% of animal species, 70% of plant species, and is currently being destroyed by humans?

Answers

Answer:

Unique Biodiversity. Eighty percent of the world's known terrestrial plant and animal species can be found in forests, and tropical rainforests are home to more species than any other terrestrial habitat. A square kilometer of forest may be home to more than 1,000 species.

Explanation:

Which statement about nuclear fission is correct? produces very little energy produces a lot of air pollution requires large amounts of matter produces tremendous amounts of energy

Answers

Answer:

produces tremendous amounts of energy

Explanation:

Nuclear fission involves the split of the nucleus of high energy radioactive elements to produce a smaller nuclei with a high amount of energy which is often used to generate electricity.

It is also a very clean source of energy due to its inability to produce carbon compounds which are mostly associated with air pollution. It also doesn’t involve a large amount of matter.

In diploid species, diploid cells may undergo either mitosis or meiosis. Haploid cells may undergo mitosis (for certain species) but NOT meiosis because

Answers

Answer:

The correct answer would be - Homologous chromosomes cannot pair

Explanation:

Haploid cells are the cells that have single set of chromosome or have the equal number of chromosome as their parent cells. Haploid cells are denoted by the n. Haploid cells are produced by the meiosis and are identical copies of their parent cells,

Haploid cells may undergo mitosis but not meiosis as their are already n number of chromosome and homologous chromosomes are can not pair and meiosis is a reduction division that produces haploid cell from diploid cells.

Thus, the correct answer is - Homologous chromosomes cannot pair

Anthony Clement is applying for a car loan. The lending institution requires a personal net worth statement. Anthony currently has $1,085.00 in cash, and his camera is worth $635.00. He also owes Vista Travel $305.00 and Kelley Electronics $83.00. Complete a net worth statement for Anthony Clement. Select Current Date in the appropriate field. Assets should be listed in order of liquidity, so Cash should be listed first. Liabilities should be reported in alphabetic order.

Answers

Answer:

Net worth statement of Anthony

Assets

Current [tex]{}[/tex]                          [tex]{}[/tex]                           $1,085.00

Property, Camera (present value)    [tex]{}[/tex]          $635.00

Total Assets        [tex]{}[/tex]                                        $1,720.00  

Liabilities

Money owed others (Vista Travel)  [tex]{}[/tex]            $305.00

Money owed others (Kelly Electronics)  [tex]{}[/tex]       $83.00

Total Liabilities          [tex]{}[/tex]                                    $388.00

Net Worth                      [tex]{}[/tex]                               $1,332.00

Explanation:

A net worth statement also known as a balance sheet statement is way to present the standing of a business at a particular time. It is a record of the assets and the values of the assets as well as the business liabilities and other outstanding financial obligations the business is to settle.

How does the tectonic activity of the terrestrial planets compare with that of the gas giants?

All of the terrestrial planets have exhibited tectonic activity, but none of the gas giants have.
All of the gas giants have exhibited tectonic activity, but none of the terrestrial planets have.
All of the gas giants have exhibited tectonic activity, but only one terrestrial planet has.
All of the terrestrial planets have exhibited tectonic activity, but only one gas giant has.

Answers

Answer:

its (A). All of the terrestrial planets have exhibited tectonic activity, but none of the gas giants have.

All of the terrestrial planets exhibit tectonic activity, but none of the gas giants have.

Terrestrial planets exhibit compact surfaces, whereas gas planets don't have compact surfaces and they are composed of hydrogen (H) and helium (He).

The planets of our solar system are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Terrestrial planets: Mars, Earth, Venus and Mercury.

Gas planets: Neptune, Uranus, Saturn and Jupiter.

The term 'tectonic plates' refers to the pieces of the solid Earth's crust (and even the plates of other terrestrial planets). These plates exhibit a movement known as tectonic activity.

Gas planets don't have a solid surface and therefore no tectonic activity can be observed in them.

In conclusion, terrestrial planets show tectonic activity, but gas giants don't have tectonic activity.

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What is the basic unit of structure and function in living things

Answers

Cell

It is the basic structural and functional unit of live.

Every organism is made up of the things tiny cell

Answer:

Cell

Hope it helps ;)

Type your response in the box.
Based on the characteristics described, which category do you think humans belong to? Why do you think
this category?
starfish
cnidaria
nematoda
annelida
echinodermata
porifera
platyhelminthes
mollusca
arthropoda
chordata
sponges jellyfish Matworms round worms mollusks segmented insects
vertebrates
worms spiders
backbone
segmentation
endoskeleton
coelom
body cavity
bilateral symmetry
tissues

Answers

Question lacks the appropriate cladogram to represent the shared characteristics with the category however, the correct cladogram is attached with the answer.

Answer:

The correct answer is - chordata.

Explanation:

Based on the characteristics given in the question, human can be placed in the category of chordata as they have multicellular body with tissue organization and also shows bilateral symmetry.

Humans also have body cavity with coelom . Endoskeleton with backbone is the present in the humans as well and known as vertebrates. So these all the characteristic present in the chordata category only.

Thus, the correct answer is - chordata.

Which of the following is NOT a way a data table can hep you in
an experiment?
A. Collect the data
B. Interpret the data
C. Make your experiment more fun
D. Organize the data collected

Answers

Answer:

A.collect the data

3. Summarize why the definition of species had changed over time

Answers

Answer:

Originally, the distinction was based on morphological differences. However, it soon became that some types of organisms had different forms at various stages in their lives, here is why

Explanation:

changed genes is passed on to the next generation. Most mutations are bad, but some of them make the organism more successful in its life. Organisms that inherit that favorable new gene are likely to become more abundant than others of the species. (geologic times)

The picture below shows the setup for an experiment involving a 1000 ml beaker, sitting on a bumer, filled with 500 ml of water, where
the bumer represents the Sun's energy, and the beaker of water represents Earth's oceans.
1000 L
500 m
Bumer
During the experiment, black pepper was added to the water as it boiled strongly, and the pepper moved in a circular pattern from the top
of the water to the bottom and back again. What does the circular pattern of the pepper represent?

Answers

The circular pattern of the pepper represents the convention currents that exists in boiling water as it is heated.

What are convection currents?

A process that involves the transfer of energy from one location to another is a convection current.

Convection currents are caused by variations in fluid density brought on by temperature gradients. A natural convection current is the phenomenon that arises from the constant replacement of the heated fluid in the vicinity of the heat source by the adjacent present cooler fluid. Natural convection heat and mass transfer refer to the improved heat and mass transmission caused by this natural convection current.

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Feathers in birds appear to have first evolved for insulation but later conveyed a new advantage in helping create light aerodynamic surfaces. This switch in function is an example of ______.

Answers

Answer:

Exaptation

Explanation:

Exaptation is the process by which the features acquire those functions for which they were not originally selected or adapted. Feather is an example of exaptation, it has appeared in various fossils of the flightless ancestors of modern birds, it later became important for flying, Once they molded for flying it adapted for that function, It is found in both behavior and anatomy.

What are the components of organ systems? Select all that apply. Cells Organs Communities Tissues

Answers

Answer:

cells tissues and organs

Explanation:

because cells make up tissues,tissues make up organs and organs make up organ systems

Based on the composition of parts, an organ system is composed of:

OrgansTissues, andCells

What are the components of organ systems?

An organ system is the highest level of organization of life.

An organ system is composed of a group of organs which work together to perform a specific function.

Organs are composed of groups of tissues performing related or specific coordinated function.

A system is composed of cells working together.

Therefore, an organ system is composed of:

OrgansTissues, andCells

Learn more about organ systems at: https://brainly.com/question/19316094

1. What changes would you suggest in your home in order to be environment-friendly?
2. Can you suggest some changes in your school which would make it environment
friendly

Answers

Answer:

Explanation:

Natural product should be encouraged against chemicals this include vinegar, citric acid from citrus fruits and bicarbonate of soda.

The use of right lightbulbs helps conserve energy at home.

A recycle bin makes the environment more confortable as it helps recyle some waste product such as paper, bottles, jar .

Schools should use fluids, non toxic chemicals that are environmental friendly for cleaning in the school

The use of plastic should be reduced in lunchroom to make the environment condusive and less of plastic waste

The schools should plant trees in the environment to encourage fresh air ansd allow for carbon fixation.

Hi can someone please correct me.

Answers

I think it’s mountains also !

Glycolysis, formation of acetyl CoA, Krebs cycle and the electron transport chain are all involved in:

Answers

Answer:

breaking down of glucose

Explanation:

Glycolysis, formation of acetyl CoA, Krebs cycle and the electron transport chain are all involved in the breaking down of glucose, also known as respiration, in living organisms.

During glycolysis, glucose is transformed into 2 molecules of pyruvate with ATP and NADH being generated in the process.

The pyruvate molecules are each oxidized to acetyl CoA, a process that leads to the release of carbon dioxide and the formation of NADH.

The acetyl CoAs then undergo a series of reactions, combining with a 4-carbon molecule and generating ATP, FADH2, NADH, and releasing carbon dioxide. The 4-C molecule is also regenerated during the process. This is known as the Krebs cycle.

All the FADH2 and NADH made from the earlier steps then enter the electron transport chain where they donate their electrons to become FAD and NAD respectively. ATP is generated and water is formed through the reduction of oxygen.

The secretion of Cortisol by the adrenal gland suppresses further secretion of ACTH by the anterior pituitary gland. What is this interaction called

Answers

Answer:

Negative feed back control

Explanation:

Hormone secretion I the body system are normally control by negative feed back.

The secretion of Cortisol by the adrenal gland suppresses further secretion of ACTH by the anterior pituitary gland interaction is called negative feedback control because a stimulus causes the release of a substance which has effects that inhibit further release of hormone. This cause cortisol hormone Concentration in the blood to be maintained within a narrow range.

It causes the reduction of its own production i.e cortisol.

Carly has wavy hair. Her father has straight hair, and her mother has curly hair, which type of inheritance pattern is responsible for Carly's wavy
hain?
ОА
codominance
OB. dominant
Incomplete dominance
OD polygenic
ОЕ.
recessivem​

Answers

Answer:codominance

Explanation:

Tell me if am wrong

Which strategies did you include in your response about diabetes prevention? Check all that apply.

Answers

Answer: My strats about the diabetes prev. is very inclusive about most of their fat obesity problem so i would take them to a surgent to get checked out and later on tested for the diabetes lvls

Explanation:

because even if they stopped eating sugar or candy they would be extremely addicted, still which would be a big change for them and their mindset.

A pond, rich in various microorganisms, dries up due to drought. How will the amoeba in the pond protect themselves from this unfavorable condition?


Answers

Answer:

The correct answer is : by secreting a thick cell wall which encloses many amoebae in it to prevent loss of water, forming a cyst until favorable conditions emerge

Explanation:

Amoeba protects itself in unfavorable conditions such as drought or less water or food availability. Amoeba takes back all its pseudopodia and secretes a thick cell wall which form three layer hard covering arout amoeba body.

This hard covering is known as the cyst  and this process known as the encystation. Amoeba remain in this cyst form until favorable conditions emerge.

Thus, the correct answer would be - by secreting a thick cell wall which encloses many amoebae in it to prevent loss of water, forming a cyst until favorable conditions emerge

All of the homeostatic mechanisms that monitor and adjust the composition of body fluids respond to changes in the:

Answers

Answer:

The correct answer would be - extracellular fluid.

Explanation:

Changes in extracellular fluid helps the homeostatic mechanism to monitor and regulate the composition of the body fluids. This process involves regulatory hormones such as anti diuretic and aldosterone in order to maintain body fluids.

It is easy to regulation of the extracellular fluid than trying to regulate 100 trillion cells present in Intracellular fluids as ICF have 10% more water in comparison of ECF.

Thus, the correct answer is : extracellular fluid.

Oxygen diffuses from alveoli in the lungs into capillaries.Oxygen diffuses from alveoli in the lungs into capillaries. Oxygen enters red blood cells, where it binds to the protein hemoglobin.Oxygen enters red blood cells, where it binds to the protein hemoglobin. Oxygen diffuses from the blood to the body's tissues, and carbon dioxide diffuses from the tissues to the blood.Oxygen diffuses from the blood to the body's tissues, and carbon dioxide diffuses from the tissues to the blood. Carbon dioxide leaves the body when exhale.Carbon dioxide leaves the body when exhale. Breathing moves air in and out of the lungs.Breathing moves air in and out of the lungs.

Answers

Answer:

Oxygen diffuses from alveoli in the lungs into capillaries 3. Oxygen enters red blood cells, where it binds to the protein hemoglobin 4. Oxygen diffuses from the blood to the body's tissues, and carbon dioxide diffuses from the tissues to the ...

Explanation:

You have before you a living organism, which you examine carefully. Which of the following should convince you that the organism is acoelomate?
A) It is triploblastic.
B) It has bilateral symmetry.
C) It possesses sensory structures at its anterior end.
D) Muscular activity of its digestive system distorts the body wall.

Answers

I believe the answer is D

Create 3
questions that
could be
answered using
the data shown in
the bar graph. Be
sure to number
your questions:

Answers

Answer:

1.what are the differences in each bar graph

2.what does each bar graph represent

3.in what time period did the Forrest change

Which statements regarding hypotheses are true? Check all that apply. Hypotheses are based on observations. Hypotheses are written when experiments are complete. Hypotheses are formed from testable questions. Hypotheses are tested with controlled experiments.

Answers

Answer: The answers are

Hypotheses are based on observations.Hypotheses are formed from testable questions.Hypotheses are tested with controlled experiments.

Explanation: I just got it right on the assignment


I want to design an experiment to see if drinking coffee makes students
score higher on tests. What is the independent variable in this
experiment?

Answers

Answer: students drinking coffee

Explanation:

The dependent variable is the one that DEPENDS on what is about to happen. In this situation, whether the students scored higher DEPENDS on if they drank coffee.

So the independent variable would be the fact that they drank coffee.

Hope this helps!

The independent variable will be the scores

Which of the following does not cause mutation? Please choose the correct answer from the following choices, and then select the submit answer button. social influences environmental influences chance chemical influences the complex process of cell division

Answers

Answer:

social influences

Explanation:

Mutation is a sudden change in the genome of an organism that is heritable. Mutation can be inherited from parents and transfer to offspring.

Environment can influence mutation this could include the soil the plant grow in, the food or drugs eaten, the chemicals expose to and its intensity.

Chemical influence cell division exposure to some chemical can inhibit cell division of increase the rate at which cell divides leading to mutation.

Mutation affects the genetic components of the individual, it is a genetic disorder. Some mutation are useful, some are deleterious

Society influence will not affect mutation.

A controlled scientific study examining variables is known as a
scientific ______ ?

Answers

Answer:

An experiment

Explanation:

The answer is an experiment

A controlled scientific study examining variables is known as a scientific experiment.

What is a scientific experiment?

A scientific experiment is an experiment that is done to calculate or check out a reason for scientific things to happen. It is done with variables, these variables are controlled, independent, and dependent.

Scientific experiment container hypothesis, a procedure, and it is done by proper regulated method and instruments.

Now variables can be the components whose study we are doing or the variable which affects the component.

A control scientific experiment will be controlled by the scientist and it is to be checked that what time and what face of the experiment is going on

Thus, a scientific experiment is a carefully planned, multi-variable investigation.

To learn more about the scientific experiment, refer to the below link:

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What is the difference between a mixture of compounds and just a compound?

Answers

Answer:

The mixture contains two or more substances mixed, but neither chemically as well as not in inexact quantity while compound includes two or more elements combined chemically and in a fixed ratio.

:)

Other Questions
For this lab, you will do some work on a GUI program. Most of the work is related to actions, buttons, menus, and toolbars.When you turn in your work for this lab, you should also turn in an executable jar file of your program, in addition to all the files from your Eclipse project. See the last section on this page for information about how to create executable jar files.To begin the lab, create a new project in Eclipse and copy-and-paste both directories guidemo and resources -- from the code directory in this linke :The guidemo directory is a package that contains the Java code of the program. The resources directory has several sub-directories that contain image and sound resources used by the program. You will be working only on the code in the guidemo package.The code directory also contains an executable jar file of the completed program, GuiDemoComplete.jar. You can run this jar file to see how the program should look when it's done. In the incomplete source code that you will be working on, the main class is in GuiDemo.java, and you can execute that file to see what the program does so far.=========================Make a MenuThe program has a toolbar at the bottom of the window. The buttons in this toolbar have icons. If you click one of the icons, you can then use the mouse to "stamp" copies of the icon onto the picture. (Note that a short sound is played when you stamp.) If you click the button "DEL", you can use the mouse to erase icon images from the picture.The toolbar is made by adding Actions to a JToolBar object. This is done in the class IconSupport, which contains a list of actions and a createToolbar method to create a toolbar from the actions.Write a method createMenu() in the IconSupport class to create and return a menu with the same functionality as the toolbar. That is, all the Actions from the actions arraylist should be added to the menu, just as they were added to the toolbar. (Remember that a menu is represented by an object of type JMenu, which can be created, for example, with: JMenu stamper = new JMenu("Stamper");)Once you have a method to create the menu, find the place in the constructor of the GuiDemo class where the menu bar is created. Use the method to create a menu, and add that menu to the menu bar. Test to make sure that it is working. When a subsidiary is acquired sometime after the first day of the fiscal year, which of the following statements is true? A) Income from subsidiary is not recognized until there is an entire year of consolidated operations. B) Income from subsidiary is recognized from date of acquisition to year-end. C) Excess cost over acquisition value is recognized at the beginning of the fiscal year. D) No goodwill can be recognized. E) Income from subsidiary is recognized for the entire year. solve the equation -3+(1) 3+(1) Underline the word in the parentheses that has the correct use of an apostrophe 7. All of the (students, student's, students') schedules are final. From this list of roots, choose good descriptions for the plants and animals you are naming. a large animal that runs very fast (Select two words.) Figure A is a scale image of Figure B.27Figure AFigure B4535What is the value of x? Textbook Ch. 1: The Constitution Handbook Pgs. 30-38 (3 sets of 3 questions) Major principles of the Constitution (3 ?S) Legislative Branch (3 ?S) Executive Branch (3 ?S) Benace Parts and Supply makes a variety of car parts. The company produces A90 parts each year. Each A90 sells for and has a contribution margin of . Currently, of fixed manufacturing overhead is allocated to the A90 product line. If Benace Parts and Supply discontinues the A90 product line, of fixed manufacturing overhead costs would be avoided. What would be the impact on total operating income if the A90 product line were to be discontinued? How do you short term goals differ from long-term goals I need help on this problem. (-5)^5/(-5)^-6 what will you use to measure the length of a copper wire of 50cm long? Open market operations are typically repurchase agreements. What does this tell you about the likely volume of defensive open market operations relative to the volume of dynamic open market operations? Which equation is equivalent to 7w 1 = 15?A: 1 - 7w = -15B: 7w = -15 + 1C: 7w = 15 1D: 7w = 15 - 1 The area of a compact disc is 78.53 square centimeters. What is the radius of the disc? Use pi = 3.14 A firm with a cost of capital of 7% is considering two projects (they are not mutually exclusive), one expected to return 9% and a second expected to return 9.5%. Which projects should it pursue Use and accessibility of internet on mobile phone determine the maximum angle theta for which the light rays incident on the end of the optical fiber of radius 1 mm are subhect to the total internal reflection along the walls of the fiber. assume that the fiber has an index of refraction od 1.2 and that the outside medium is air. note that the rays refracts when entering the fiber g Foods with a high ratio of nutrients to calories?Which one is the answer?1.Calorie dense foods2.Nutrients dense foods3.Fast food4.Texas Roadhouse The idea that the moon, sun, and known planets orbit Earth is called the _______________ model of the universe. What equation represents a population of 300 animals at the crease and an annual rate of 23%