Factors that must be kept constant in the experiment to obtain valid results are option (c) i.e, type of antibiotic, nutrient agar, and temperature.
what are antibiotics?A particular class of antimicrobial agents that works against bacteria is an antibiotic. Antibiotic drugs are frequently employed in the treatment and prevention of bacterial infections because they are the most effective type of antibacterial agent for doing so. Bacteria may be killed or have their growth suppressed.
They could harm the bacterial cell directly by attacking the cell wall. These cells can no longer do additional harm to the body since the bacteria cannot attack it. Other antibacterials, such as tetracycline and erythromycin, prevent the germs from multiplying or growing.
Antibiotics limit bacterial growth and replication by interfering with the bacterial cell wall. Because many types of bacteria have cell walls but human cells do not, antibiotics can kill bacteria while sparing human cells.
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Which evidence is provided by fossil record
The fossil record
This supports Darwin's theory of evolution, which states that simple life forms gradually evolved into more complex ones. Evidence for early forms of life comes from fossils. By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. What traces there were may have been destroyed by geological activity. This is why scientists cannot be certain about how life began.
Fossils provide a snap shot of the past and allow us to study how much or how little organisms have changed as life developed on Earth.
Which are ways that humans can lower biodiversity as they us environment? Check all that apply. A. Converting a forest to soccer fields B. Spraying pesticides on lawns An C. Building roads across tundra D. Replacing riverbanks with concrete bulkheads and
Answer:
A, B, C, and D
Explanation:
All of the options represent ways by which humans can lower biodiversity as they use the environment.
By definition, biodiversity or biological diversity of an area refers to the total number of living organisms that are domicile in that area.
Converting a forest to a soccer field requires that the variety of plants and animals in the forest are removed and the forest soil is planted with turfs in their place. Thus the biodiversity of the forest has been greatly reduced in other to pave way for a soccer field.
A pesticide is an agrochemical that kills pests. Pests are biological organisms even if they are not that desirable on the lawn. Thus, killing them off using a pesticide is a way of reducing the biodiversity associated with the lawn.
A tundra represents an ecoregion with its own characteristic plants and animal, even if they are few. Hence, building roads across tundra requires that portions of the biodiversity are removed to pave way for the road.
Riverbanks serve as habitats for a variety of living organisms. Replacing them with concrete bulkheads means that the habitat is lost and the organisms displaced. Thus, the biodiversity of the region gets reduced.
Therefore, options A, B, C, and D are all correct.
What do you think energy really is?
Answer:
sugar
Explanation:
The following lines from Frost's "The Road Not Taken" indicate what about the Speaker? Line 2: And sorry I could not travel both Line 3: And be one traveler long I stood A. The spaaker is waiting for someone TOT a long time ("long I stood"). B The speaker is traveling by himself- just "one traveler." C. The speaker is sorry he can't travel both roads can you help me
Which neurotransmitter is a major regulator of mood and behavior and can be chemically altered using drugs like Prozac or Zoloft?
a) nitric oxide
b) substance P
c) norepinephrine
d) serotonin
e) acetylcholine
Explanation:
Serotonin is an inhibitory neurotransmitter that responsible for regulating the bodies mood and behavior in the central nervous system and affect the functions of the entire body. Prozac and Zoloft are antidepressants that help retain more serotonin neurotransmitters in neurons.
Answer:
d) serotonin
Representation of system or object such as charts or maps are
Answer:
graphical models
Explanation:
Can someone help me understand this plz
Question 13 of 35
Which option describes the direction of thermal energy transfer in Earth's
oceans?
A. From the poles to the equator
B. From cool areas to warm areas
C. From the ocean floor to its surface water
D. From the equator to the poles
SUBMIT
Answer: D. From equator to the poles.
Explanation: took the exam
As atmospheric CO2 increases, the amount of CO2 dissolved in seawater is expected to increase as well. This produces more carbonic acid, which then dissociates into hydrogen ions and something else.
Answer:
(HCO3-) bicarbonate
Explanation:
What two kinds of information do you need to describe the velocity of an object?
Answer:
magnitude and direction
Help me plsssss 10 points only sorry The letter c is C. Energy
Answer:
non luminous is your answer.
Which organism is a producer?
mouse
snake
owl
grass
Answer:
Grass
Explanation:
since producer is the first thing in the food chain its grass
Answer:
It is grass Duh!
༼ つ ◕_◕ ༽つ
One of the following causes Creutzfeldt - Jakob disease?
Answer:
is caused by an abnormal infectious protein in the brain called a prion. Proteins are molecules made up of amino acids that help the cells in our body function.
Explanation:
Light waves are a type of electromagnetic wave.
The wavelengths of light range from 400 nm to 700 nm.
Light waves are transverse waves
• The speed of light is 3 x 108 m/s.
Which statement can be inferred from the data?
O Light waves can transport matter through mediums and empty spaces.
O Light waves transmit energy by compressing the particles in mediums.
O Light waves can travel with and without mediums.
O Light waves transfer the particles of mediums in the direction of travel.
Answer:
Light waves can travel with and without mediums.
Explanation:
Light waves are a type of electromagnetic wave. Some of the characteristics (properties) of light waves include;
I. The wavelengths of light range from 400 nm to 700 nm.
II. Light waves are transverse waves.
III. The speed of light is 3 x 10^8 m/s.
Therefore, from the aforementioned characteristics it can be inferred that light waves can travel with and without mediums.
This ultimately implies that, light wave is an electromagnetic wave that do not require a medium of propagation for it to travel through a vacuum of space where no particles exist.
i am thick and stiff
i have boxlike shape
i am found only in plants
i am what makes them to stand upright
Answer:
belt?
Explanation:
if you were not able to experience the above listed changes, what might have caused such difference?
Answer:
If you don't experience the listed changes above you will get very curious about yourself and you might lose some confidence due to not being able to experience some changes others have experienced.
The green machines within a plant are the blank.
Lysosomes chloroplasts mitochondria
lauren was walking in the woods when she found a rotting log. when she looked closely at the log, she saw that a decomposer was working to break down the wood. which could be the decomposer she saw on the log?
A. grass
B. mouse
C. mushroom
D. caterpillar
Answer:
C. mushroom
Explanation:
what is the best cancer books which I can read them?
An osteocyte is a main cell type in which tissue ?
1) adipose
2) cartilage
3) loose connective tissue
4) bone
5) blood
Answer:
Bone-
Explanation:
A biologist studies a population of anteaters living in a large nature reserve. The reserve is surrounded by farms where anteaters are not safe, but the reserve is a perfect place for anteaters: there are few predators and lots of ants. The biologist counts the number of anteaters in the reserve every year for twenty years and finds the size of the population does not change much. Which of the following is the best description of what life in this reserve is probably like for these anteaters?a. The anteaters have little or no difficulties obtaining food and raising offspring. ants. Their tongues are 24 inches long and covered with sticky saliva. Anteaters cannot open b. Adult anteaters compete for food and many young anteaters die. theirmouth, and do not have teeth. Even the stomachs of anteaters are unique: unlike most mammals,c. It is impossible to know without actually observing anteaters in the reserve.
Answer:
Adult anteaters compete for food and many young anteaters die
Explanation:
As there are not many predators and the number of ants is abundant, the population of anteaters should grow on a large scale, however, this is not what happens, since the size of the population is the same for twenty years. This shows that the anteater population itself is regulating the size of the population through internal disputes, where anteaters, due to the high birth rate, end up competing for food and shelter, causing the most young and inexperienced individuals to be killed.
Nitrogen is "fixed" by plants
O True
O False
Answer:
i think it is false. because symbiotic soil microbes do that
When water seeps into the ground the hydrosphere is interacting with what sphere?
Answer:
When water falls and seeps into the ground it actually interacts with the lithosphere
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Answer:
1) bone marrow
2)stores fat
3) calcium
4)tough tissue
What is NOT apart of a seed?
Answer:
A) Stigma
Explanation:
This option makes the most sense of all of them. The food storage option is incorrect because food storage is a part of a seed. The stigma is part of producing the seed, not part of the actual seed. The testa is the seed coat (part of a seed). The plumule is also part of a seed (stem or seedling).
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A membrane attack complex is a protein grouping that Multiple Choice stimulates basophils to attack a multicellular parasite in the body. triggers phagocytosis of a target cell by a nearby macrophage or neutrophil. links a pathogen to a red blood cell so that it is carried to the liver or spleen. forms a channel in the target cell membrane that causes cytolysis.
Answer:
The correct answer is ''forms a channel in the target cell membrane that causes cytolysis.''
Explanation:
The membrane attack complex (MAC) has the essential effect of producing a notable osmotic imbalance in the microorganism that leads to its cytolysis (in Gram-negative bacteria it inserts into the outer membrane, favoring the entry of lysozyme, and in Gram-positive ones insert into the cytoplasmic membrane, destroying the electrochemical gradients). The lytic pathway corresponds to the final reactions of the complement system. It begins when the C5 convertase enzymes formed either in the classical pathway, MBL or the alternative, fix the factor C5 and fragment it into C5a (anaphylatoxin) that passes into the fluid medium and C5b, which binds non-covalently to C3b. The C5b fraction captures C6 and C7 from the fluid phase, forming a stable C5b67 complex with chemotaxic activity and membrane-binding capacity, which when joining the C8 fraction is cytolytic, and acquires the ability to interact with C9 molecules, forming the complex C5b6789. The C9 molecules then undergo conformational changes, enhance and accelerate the penetration of this membrane attack complex (MAC), giving rise to the formation of channels that allow the free exchange of sodium and water with the outside of the cell, causing the consequent osmotic lysis (cytolysis)of the attacked cell, since C9 is structurally homologous to perforin, a protein released by cytotoxic T lymphocytes and NK cells, and which is also responsible for the formation of pores in the membrane of the target cells.
The following is an example of mechanical energy
a. Riding a bike
b. Eating food
c. The sun
d. A fire giving off heat
Answer:
The answer is A.
Explanation:
Because it involves motion and kinetic energy.
What 3 types of science formed the geological time scale?
a) archaeology, paleontology, astrology
b) Scientology, astronomy, and geology
c) geology, archaeology, and paleontology
d) paleontology, Scientology, and biology
Answer: c) geology, archaeology, and paleontology
Explanation:
The geological time scale can be defined as a scale which is used to determine the chronological dating of the organisms in the geological strata. It helps in determining the occurrence and existence of particular kind of species on planet earth. It can also be used to trace the development and passage of a particular kind of trait from one generation to the another. It can also be used to trace back various geological events that occurred on planet earth like volcanic eruption, plate tectonics, and others. The geologists used it for tracing the geological activities that occurred in the history of earth. Archaeologist study about rocks and fossils to trace back the geological time scale. Paleontologist study the existence of a particular species via studying the fossil evidences and reconstructing the primitive conditions by developing a geological time scale. They trace the evolutionary history of organisms.
wh is cell called the functional unit of life?
Answer:
because the cell is the smaller unit that has the properties of life
Explanation:
There are three basic principles/statements that are the basis of the unified cell theory, which was proposed by Matthias Schleiden and Theodor Schwann in 1838. All living organisms are composed of cells (first principle), whereby cells can be considered as the basic, structural and organizational units of all organisms (second principle). Moreover, new cells always arise from existing cells (third principle). In consequence, the cell is the smaller unit that has the properties of life in order to carry out all metabolic processes including reproduction, growth, development, etc.
A gallon of olive oil sitting on a high shelf is likely to have:
a. Kinetic Energy
b. Gravitational Potential Energy
c. Electrical Energy
d. Nuclear Energy
Answer:
b. Gravitational Potential Energy
Explanation:
The olive oil currently holds potential energy, which it is given from the pull of gravity, constantly pulling it down to the earth.
If the olive oil were knocked down the gravitational energy would then be kinetic, or moving. The other choice simply don’t make sense, as the olive oil is unlikely to be electrically charged, nuclear reactive, or -as it’s not currently moving- have kinetic energy. Therefore the proper response is:
b. Gravitational Potential Energy
The principal enzyme involved in DNA replication is called . The enzyme joins to synthesize a new strand of DNA . DNA replication is called , because each new DNA molecule is made up of one original and one new strand.
Answer:
1. DNA polymerase
2. Nucleotides
3. Complementary
4. Semiconservative
Explanation:
I took the quiz.
The enzyme in DNA replication is DNA POLYMERASE, it joins NUCLEOTIDES to synthesize a COMPLEMENTARY strand of DNA. DNA replication is SEMICONSERVATIVE.
DNA polymerase is an enzyme that adds nucleotides to the growing DNA strand.This DNA strand is complementary to the template DNA strand.DNA replication is semiconservative because each daughter DNA molecule contains a new DNA strand and one original strand.In conclusion, the enzyme in DNA replication is DNA POLYMERASE, it joins NUCLEOTIDES to synthesize a COMPLEMENTARY strand of DNA. DNA replication is SEMICONSERVATIVE.
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