Pasteur's experiments proved that ________. Pasteur's experiments proved that ________. spontaneous generation can only occur if nutrient broth is left open to the environment cells cannot survive in swan-necked flasks preexisting cells present in the air can grow in sterilized nutrient broth sterilizing nutrient broth prevents spontaneous generation in order to grow, cells need to be supplied with oxygen

Answers

Answer 1

Answer:

preexisting cells present in the air can grow in sterilized nutrient broth

Explanation:

Spontaneous generation, which is the theory that life can arise from nonliving matter, has long been believed to be the way living organisms develop. However, in 1858, a French scientist called Louis Pasteur disproved the theory of spontaneous generation.

Louis Pasteur conducted an experiment to show that it is the existing microorganisms in air that causes life to grow and not the air itself. Pasteur made use of a swan-necked flask, which contained a sterilized (by boiling) broth. The swan-necked flask was designed in such a way that it would allow air to enter but trap any airborne microorganism, preventing them from reaching the broth.

Hence, if it were truly air and not existing life organisms that caused life growth, organisms should begin to grow from the broth. He conducted another experiment where be broke the neck of the flask to allow the entry of microorganisms into the sterilized broth and found out that growth of microorganisms occured on the broth.

Therefore, Pasteur, via his experiment was able to prove that preexisting cells present in the air can grow in sterilized nutrient broth if allowed entry but when there is no entry, there would be no life growth. This experiment disproved the theory of spontaneous generation.


Related Questions

steps of Biological method of study taking malaria as an examples

Answers

Explanation:

The different steps which are involved in biological method are the the invasion, the rapid division followed by the spread of infection. ... Malaria results in infection after the bite of the female anopheles mosquito. The parasites enter the bloodstream. as a result of this there is predominant infection.

a) dry apricots are left transferred to sugar solution?

Answers

When dry apricots are left for sometime in pure water, they will swell. Because, water will enter into them through the process of osmosis. Later,when these apricots will be transferred to sugar solution, they will again shrink.

Please if you can, please help..
What is an allele that isn't expressed called?
Dominant allele
Recessive allele
Genotype
Phenotype
The final phase of translation, called termination, is signaled by three nucleotides, called a __________, that mark the end of a polypeptide chain.
Plasmid
Exon
Intron
Stop codon

Answers

Recessive allele
Stop codon

Explain how scientific knowledge develops through making observations about the natural world.

Answers

Answer:

Scientific knowledge develops through making observations about the natural world. An observation may generate a scientific question, which may lead to a hypothesis. The hypothesis can be tested through experimentation. The results of experimentation lead to changes in scientific knowledge.

Explanation:

Explain how scientific knowledge develops through making observations about the natural world.  my answers are never wrong trust me

Which statements accurately describe the roles of water on earth

Answers

Answer:

C.

Explanation:

It carries cold water from the equator to the poles

Consider this animal cell. The organelles in an animal cell are labeled. Part E represents small dots on the nucleolus. What is the function of the small, dark organelles labeled E? They contain enzymes for the digestion of old cell parts. They regulate what enters and leaves the cell. They produce proteins for the cell. They store water and other materials.

Answers

The dark organelles labelled E is called the Ribosomes.    

The answer is Ribosomes

What are the similarities and differences of homeothermic organisms and poikilothermic organisms.

Answers

Answer:

Poikilothermic organisms are ectothermic (obtain heat from their environments), while homeothermic organisms are endothermic (regulate body temperature physiologically)



Choose all the answers that apply.

Rapid burial _____.

increases exposure to oxygen
decreases exposure to oxygen
slows down the rate of decay
prevents scavengers from eating organism remains





















































































































































































































Answers

Answer:Organisms decompose more quickly when they are in contact with oxygen. Most environments exposed to the open air are in contact with plenty of oxygen, so the soft tissues of dead organisms, whether plants or animals, decay quickly. ... For an organism to become a fossil, it must not decompose or be eaten.

Explanation:

Object is not moving Answer 1 Choose... Object is moving towards observer Answer 2 Choose... Object is moving away from observer Answer 3 Choose...

Answers

Answer:

Object is moving away from observer.

Explanation:

If a force is applied to an object it starts moving. The object will move towards the observer, this is known as Doppler effect. It is when an observer or the thing under observation moves. There is change in its position due to a force exerted on it. The motion of the object also depends on the direction of force.

The lac operon in Escherichia coli Group of answer choices promotes the expression of lactose-utilizing enzymes when lactose is absent from the environment. prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment. prevents lactose intolerance. prevents lactose-utilizing enzymes from being expressed when lactose is present in the environment.

Answers

Answer:

The correct answer is - prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment.

Explanation:

The lac operon or the lactose operon is a operon that is essential for the many bacteria like Escherichia coli for metabolism and transport of the lactose.

In the presence of the lactose in the environment of the cell the lac genes are expressed due to the isomer of of lactose called allolactose binds to the Lac repressor protein and do not allow to bind it to lac operator. But in the absence of the lactose, the lactose utilizing enzymes are not expressed  due to repressor bind to the lac operator and prevents the binding of RNA polymerase to the promoter.

Describe and explain how temperature and light intensity affect the rate of photosynthesis?

Answers

Answer:

The rate of photosynthesis varies with light intensity and temperature.

Explanation:

The rate of photosynthesis varies with light intensity.it decreases as light intensity decreases and increase s as light intensity increases. However at much higher light intensity rate of photosynthesis becomes constant.

The rate of photosynthesis decreases with decrease in temperature.It increases as temperature is increased over a limit. But if light intensity is low increase of temperature has little influence on rate of photosynthesis.

What results if a broken chromosomal fragment becomes reattached as an extra segment to a sister or non-sister chromatid? A Duplication B Inversion C Polyploidy D Nondisjunction

Answers

Answer:

The correct answer is option A "Duplication".

Explanation:

Chromosomal duplication is defined as a type of rearrangement of genetic material at which extra copies of a DNA fragment are created. In this case if a broken chromosomal fragment becomes reattached, this fragment will represent an extra copy, and therefore the resultant genetic material is considered a chromosomal duplication.

Match the causes with their effects.

Answers

Answer:

"destroys->deforestation"

"Oil spills->harms aquatic"

"injecting->pollutes"

1. deforestation

2. injecting fracking fluids into the ground

3. oil spills during transport on a ship

How do the leaves help trees survive in their respective biomes? A. The temperate leaves are broad and flat to maximize sunlight absorption, while the taiga leaves are long and thin to minimize sunlight absorption. B. The temperate leaves are thin to minimize absorption of sunlight, while the taiga leaves are specialized to store water during the dry season. C. The temperate leaves shed water during the wet season, while the taiga leaves can enter long periods of dormancy during colder weather. D. The temperate leaves grow in the spring and shed in the cold, while the taiga leaves are dark and wax-coated to prevent the tree from freezing.

Answers

Answer:

The correct answer is option D.

Explanation:

The temperate leaves grow in temperate forests found in America, Europe, and Asia. This biome comprise of trees have evergreen conifers with needle like leaves. Such leaves can endure wide change of temperature and light. Some vegetation of temperate biome are conifers such as Pine, Hemlock and other. The trees shed their leaves with the beginning of fall and new leaves are delivered in late-winter  to protect from the cold.

On other hand, Taiga forest is the biggest biome on the planet. This biome contain conifers with long, slender waxy needles like leaves. These waxy leaves provide security against freezing temperature and from dying drying out. In contrast to temperate they don't sheds their leaves in winter and keep their needles throughout the entire year.

Thus, the correct answer is option D.

Answer:

D. The temperate leaves grow in the spring and shed in the cold, while the taiga leaves are dark and wax-coated to prevent the tree from freezing

Explanation:

Got it right on Edmentum

what is the role of pancreas in digestion

Answers

Answer:

Explanation:

The pancreas is a glandular organ in the digestive system and endocrine system located in the abdominal cavity behind the stomach. It is an endocrine gland producing several important hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide, all of which circulate in the blood.

The pancreas produce pancreatic juice which has pancreatic enzymes that continue the digestion of proteins, carbohydrates and fats in the duodenum. Always remember that unlike the gastric juice pancreatic juice is alkaline.

What is an example of medicines whose molecular structure has been designed to interact with specific target molecules in living things?

Answers

Answer: G protein- coupled receptor

Explanation:

Drug target is when a native protein activity in the body is modified by a drug resulting in a desired therapeutic effect.

G protein is an example of target drug that has been deisgned to modified the affect of certain protein in the body to aid treatment.

The first thing is to Identify the biological origin of the disease and then the target that can be used to combat the Ailment.

12. What group of organisms are most in danger of extinction?

those with small populations

both a and b

those with large populations that breed quickly

those that migrate or need special habitats

Answers

Answer:

Both A and B

Explanation:

CER

Can someone help me with these questions? Thank you.

Answers

Answer:

1.C

2.E

3.C

4.R

5.E

6.R

7.E

8.C

9.E

(do not take my word for it maybe wait for someone else to answer to compare to mine)

Part D What strengths and weaknesses do you see in your improved model?

Answers

Answer:

The new model correctly shows the process of oxygen and carbon dioxide exchange that takes place in the capillaries. However, it does not show that this oxygenated blood travels back to the heart for distribution to the body. It also does not show the structure of the alveoli.

Explanation:

PLATO answer

CH2OH О, a CH3 H OH OH Н он Identify the macromolecule pictured above. O a Ob Protein Carbohydrate Lipid , ос Od Nucleic Acid​

Answers

Answer:

Although the pictorial representation is not clear but the question can be answered based on the known structure of each biomolecule. The answer is:

Carbohydrate

Explanation:

Carbohydrate is one of the four biological molecules in living systems. Carbohydrates are composed of long chains of carbon, hydrogen and oxygen in a 1:2:1 ratio i.e (CH2O)n empirical formula.

The structure of carbohydrate is composed of a ketone (C=O) or aldehyde (CHO) functional group and hydroxyll groups (OH). The simplest unit of any carbohydrate is called a monosaccharide. Hence, from the above structure in the question, which consists of long chain of carbon, hydrogen and oxygen atoms, it can be identified as a CARBOHYDRATE.

Describe five of these properties and provide an example of each: Hydrogen bonding, cohesion and adhesion, surface tension, heat of vaporization, specific heat, density, and universal solvent

Answers

Answer:

Explanation:

Hydrogen bond is an intermolecular force of attraction, it occur between a proton in a molecule and an electronegative atom in the another. It is weak bond and can be found in water molecule.

Cohesion is force of attraction thst occur when molecules are attracted to other molecules of the same type

this can be found in hydrogen bonding.

Adhesion occur when molecules are attracted to different substances. It can be founf in water when reaction with other substance

A universe solvent is a substance that is used to dissolves many substance. Example is water it can be used in dissolving many substance.

Surface tension is the ability of a liquid surfaces to reduce into the minimum surface area. It allows some insect that are less dense to float in water

Head of vapourization is the amount of heat required to change a liquid into a vapor. Heat to convert water into vapour

Answer:

pH

Explanation:

"The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution. The letters pH stand for 'power of hydrogen' and numerical value for pH is just the negative of the power of 10 of the molar concentration of H+ ions."

hope this helps :)

What is a protein that is the main component of the thick filaments in muscle fibers and is responsible for muscle contraction?

Answers

Answer:

Myosin

Explanation:

Two of the important proteins are myosin, which forms the thick filament, and actin, which forms the thin filament. Myosin has a long, fibrous tail and a globular head, which binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement

Answer: actin

Explanation:

Algae in the genus Caulerpa typically grow to a length of over half a meter and have structures similar to stems,leaves,and roots.Reproduction occurs when adults produce sperm and eggs that fuse to form offspring.Each adult Caulerpa consists of just a single cell,however.Which of the following statements is true?
A) Caulerpa violate the pattern component of the cell theory that all organisms consist of cells.
B) Caulerpa violate the process component of the cell theory that all cells come from preexisting cells.
C) Caulerpa violate both the pattern and process components of the cell theory.
D) The existence of Caulerpa is consistent with the cell theory.

Answers

Answer:

D) The existence of Caulerpa is consistent with the cell theory.

Explanation:

This question describes species of algae in the genus, Caulerpa, which is a unicellular organism that possesses structures similar to leaves, stems and roots in plants. It also grows to a length of about 0.5metres. it reproduces sexually by fertilization of gametes (sperm and egg).

According to all these described characteristics of Caulerpa, it's existence is in conformity or accordance with the unified cell theory, which was proposed by three scientists namely: Matthias Scleiden, Theodor Schwann, and Rudolf Virchow in the 1830's. The three components of the cell theory states that:

1. Cell is the fundamental and basic unit of life existence.

2. All living organisms are composed of one (unicellular) or more cells (multicellular).

3. All cells come from already preexisting cells.

Hence, based on the components of the cell theory and the life pattern of Caulerpa i.e. Caulerpa is made up of one cell, it is made from the fusion of preexisting parental cells etc. It is consistent with the cell theory.

The gallbladder is most accurately described as:________ A. The source of urea B. The storage site for fat and minerals C. The duct that drains the tail of the pancreas D. A distensible sack that concentrates and stores bile

Answers

Answer:

D. a distensible sack that concentrates and stores bile

Explanation:

The gallbladder is a small pouch that sits just under the liver and stores bile that is secreted from the liver until it is released into the intestines.

Hope that helps.

A doctor suspects that one of her patients has a deficiency in one of the six key elements found in living organisms. He has low energy and extremely weak, soft bones. Based on this information alone, which nutrient supplement will she most likely prescribe? phosphorus zinc sodium sulfur

Answers

Answer:

The answer is: phosphorus

As human travel increases, the number of introduced species likely
decreases.
increases
stays the same
is eliminated

Answers

Answer: The correct answer to the question is option B

INCREASES.

As human travel increases(As humans move from one place to another),the number of introduced species likely increases because as humans move from one place to another,they introduce new species of organisms to their new environment.

These non-native species grow in this new environment,becomes economically important and doesn't pose any harm to their new ecosystem unlike invasive species that poses a substantial harm.

The number of introduced species are likely to : ( B ) Increases

As Humans migrate from one place to another they introduce new species into their new environment naturally or artificially.

Migration

The movement of humans or any type of organism comes with the introduction of new species because as they move they take along with them certain species that naturally do not belong to their new environment.

Hence we can conclude that As human travels The number of introduced species are likely to Increase.

Learn more about Human migration : https://brainly.com/question/1213023

Which effects are factors in long-term climate change? Check all that apply.

Answers

decrease in sea ice
increase in permafrost thawing
increase in heat waves
heavy precipitation

Answer:

Earth's orbit around the Sun . Right

ice forming on a lake . Wrong

solar energy . Right

volcanic eruptions. Right

thunderstorms. Wrong

Explanation:

The location where sea floor spreading occurs is called the

Answers

Answer:

The location where sea floor spreading occurs is called the mid ocean rigid.

Explanation:

Hope it helps you....

Thank you..☺..

Which is most likely a source of air pollution?

Answers

Answer:

CFC's

Explanation:

through what are larger molecules are formed?​

Answers

Answer:

Through combination of each monomer using covalent bonds.

Explanation:

Most macrmolecules are made from single subunits or building blocks called monomers combine with each other using covalent bonds to form larger molecules known as polymers. In doing so, monomers release water molecules as byproducts.

Other Questions
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There are three kids in the class named John, Betty, and Mary. The useof the word "or" in the description of the events, should be interpreted as the inclusive or. That is"A or B" means thatAis true,Bis true, or bothAandBare true.Give an expression for each of the probabilities below as a function ofn. Simplify your final expressionas much as possible so that your answer does not include any expressions of the form (a/b).Requried:a. What is the probability that Betty is first in line or Mary is last in line? b. Explain the method used to calculate probability. How is the Law of Conservation of Mass being followed in a voltaic cell with a zinc anode and a copper cathode? A. No mass is lost because electrons are flowing, not atoms. B. The mass lost by the copper electrode is gained by the zinc cathode. C. The Law of Conservation of Mass is not followed when electricity is generated. D. The mass lost by the zinc electrode is gained by the copper cathode. 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Combine the radicals. 224+554 A) 536 B) 56 C) 196 D) 936 Please answer fastshort notes on 1. energy giving food and 2.body building food At what speed (in m/s) will a proton move in a circular path of the same radius as an electron that travels at 7.45 106 m/s perpendicular to the Earth's magnetic field at an altitude where the field strength is 1.10 105 T pls help!!! which excerpt from the story of my life by Hellen Keller contains the best example of the author's use of vivid verbsa.my teacher placed my hand under the spoutb. the most important day I rememberc. anger and bitterness had preyed upon med. but I did not know this until afterward What are the main types of reading tools 15. How many moles of carbon tetrachloride (CCI) is represented by 543.2 g of carbon tetrachloride? 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