Answer:
Some pathogens are transmitted by a single route and others by several, the more transmission routes are recorded, the more pathogens they are, in the HIV virus the transmission is vertical and horizontal therefore it has high pathogenicity, on the other hand, the varicella virus is transmitted only by inhalation.
Explanation:
The vertical route is the transmission through childbirth, it is the moment in which the mother contacts the child's blood and transmits the virus, nowadays the vertical contagion of HIV is highly controlled.
On the other hand, the horizontal route is also called parenteral, it is one that consists of the inoculation of the virus through uncontrolled blood transfusions, intravenous drug addiction by syringe compartment, or uncontrolled injections.
There is a healthy bacterial culture growing in the exponential phase . A technician wants to make a growth curve by making cell counts over the day . She plans to take the samples every 30 minutes during the day , hold the samples at room temperature , and then process all samples together at the end of the day .
A) what is the problem with her plan?
B)can she do anything to improve the accuracy of her results ?
A) WHAT IS THE PROBLEM WITH HER PLAN?
Binary fission is one of the asexual process by which most bacteria reproduce, the binary fission brings about a doubling of the number in bacterial cells that are viable.
Generation time is that time that it will require for a cell population to divide and double, it is also known as doubling time. This Generation time varies among distinct organisms and also varies among culture conditions.
Take for instance,a fast growing bacterium that is under an ideal culture conditions has a doubling time of 20minutes and for the bacteria that is grown in a condition that is not so ideal,may have a doubling time of hours.
The major challenge/ problem with her plan is that as she takes the bacterial sample every 30minutes, and then hold the sample till the last sampling is done in the day,those bacterial cells that are collected in the initial intervals will then get divided and further gives a result that is false.
However,if those bacteria that are collected aren't stored in a culture environment that is standard,the bacterial cells may die off and thus will further bring about a false result.
2) CAN SHE DO ANYTHING TO IMPROVE THE ACCURACY OF HER RESULT?
Solution for rectifying the error in her plan;
She can go ahead and add 50-100 μl of formaldehyde to all the culture suspensions that she has and has taken every 30minutes.
As the formaldehyde will fix the bacterial cells,The optical density present in all those aliquots can then be retrieved/taken at the end of the day.
Looking at it alternatively, aliquot 1ml of the culture suspension at an interval of every 30 minutes,and then take the optical density that is OD at a wavelength of 600nm making use of spectrophotometer until the reason you get becomes static.
Please help it’s urgent!!! For these 2 questions
Answer:
The first question is endothermic change of state. The second answer is 75% of our bodies are made up of water
Explanation:
I think this is the answer Hope this helps and I'm sooo sorry if this is wrong.
Which sentences describe the differences between photosynthesis and cellular respiration? Check all that apply. Cellular respiration uses oxygen as a reactant and photosynthesis does not
Answer:
Cellular respiration uses oxygen as a reactant and photosynthesis does not
Explanation:
Autotrophs use CO2 to make energy while heterotrophs use Oxygen.
Check all that apply?You only gave one option so that's as far as I can get, sorry!
What does the cell membrane do for the cell?
O maintain homeostasis
O all of the above
O communication
O protection
Answer:
Protection
Explanation:
The plasma membrane, or the cell membrane, provides protection for a cell. It also provides a fixed environment inside the cell. And that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.
What stages of replication do both cycles have in common? Describe the virion action at each of these stages.
Answer:
Attachment, Penetration and Replication
Explanation:
A bacteriophage is a virus that attacks bacterial cells. The lytic and lysogenic cycles are two methods of viral replication. In the lytic cycle, the virions produced are released from the host cell whereas in the lysogenic cycle, viral nucleic material are incorporated into host nucleic material and are copied to daughter cells when the host cell reproduces. The common steps in both cycles are given below:
1 Attachment – in this step, the bacteriophage attaches itself to the surface of the host cell so as to insert its DNA into the host cell.
2. Penetration – the virus inserts its DNA into the host cell by penetrating the cell membrane of the host cell.
3. Replication – the viral nucleic material is replicated using the host cell's replication mechanism.
The stages of replication is Attachment, Penetration and Replication
The following information should be considered:
A bacteriophage means the virus that attacks bacterial cells. The lytic and lysogenic cycles comrpise of two methods of viral replication. In the lytic cycle, the virions generated are released from the host cell while on the other hand in the lysogenic cycle, viral nucleic material are existed into host nucleic material and also they are copied to daughter cells at the time when the host cell reproduces.The common steps in both cycles are given below:
Attachment – in this step, the bacteriophage attaches itself to the host surface cell to insert its DNA into the host cell. Penetration – the virus inserts its DNA into the host cell via penetrating the cell membrane of the host cell. Replication – the viral nucleic material is replicated using the host cell's replication mechanism.Learn more: https://brainly.com/question/20492533?referrer=searchResults
The reaction shown below is known as what type of reaction?
Reactants → Products + Heat
А. activation
B. endothermic
c. enzymes
D. exothermic
Red blood cells are able to maintain homeostasis because they are bathed in blood, which is to the fluid in the cells themselves.
Answer:
this is not a question it is a statement
Explanation:
What would be the best control group for global warming? Select one: (A)laboratory simulation,(B )a computer simulation or (C) another identical earth that has not seen increases in greenhouse gases (even though this is not possible)
Answer:
C. another identical earth that has not seen increases in greenhouse gases
The best control group for global warming would be another identical earth that has not seen increases in greenhouse gases.
What do you mean by Global warming?Global warming may be defined as the gradual increase in the Earth's average temperature due to the trapping of greenhouse gases by the atmosphere.
The excessive release of greenhouse gases like methane, Carbon dioxide, nitrous oxide, and ozone are responsible for global warming. These gases are released by automobiles, industrial smoke, etc.
Deforestation is also considered the cause of global warming. Trees help in the reduction of carbon dioxide from the atmosphere and convert it into oxygen.
Therefore, the best control group for global warming would be another identical earth that has not seen increases in greenhouse gases.
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9. A pattern of stars that has been named is called a constellation. One winter evening, Jason
found the star called Sirius in the constellation called Canis Major.
Canis Major
Sirius
Muliphen.
Murzim
Wezen
Aludra
Adara
If Jason came outside again a few hours later, what would the stars in Canis Major look like?
A. The pattern of stars would appear to be in the same place in the sky.
B. The pattern would change because each star would have moved in a different direction.
C. The pattern of stars would appear to have moved together across the sky.
D. The pattern would be smaller because the stars moved closer together.
Answer
i think its C.
please help me with this question:)
400x
Is the answer to this question.
Step 1: Add approximately 25 mL of water to a 50-mL graduated cylinder.
Step 2: Measure and record the initial volume of the water to the nearest 0.1 mL.
Step 3: Carefully slide the object into the graduated cylinder. Measure and record the final volume of the water to the nearest 0.1 mL.
Step 4: Determine the volume of the object by subtracting the measurements in steps 2 and 3.
What pattern in these data could be used to predict the final volume if the initial volume is known?
The final volume is the sum of the initial volume and the volume of the object.
The initial volume is the sum of the final volume and the volume of the object.
The volume of the object is the sum of the initial volume and the final volume.
The final volume is the difference between the initial volume and the object’s volume.
Answer:
The final volume is the sum of the initial volume and the volume of the object.
Explanation:
Since we know that the volume of the object is the difference between the final and the initial volume, let the volume of the object be ∆V, let the initial volume be V1 and let the final volume be V2.
From;
∆V= V2 - V1
V2= ∆V + V1
Hence the answer above
The most important structure in the lower respiratory tract is the alveolus.
O True
O False
Answer:
true
Explanation:
the lower respiratory tract contains:- trachea, bronchial tree, and lungs.
a metacentric chromosome is one that has a centrally located centomere and chromosome arms with approximately equal length. which of the human chromosomesare metacentric
Answer:
Human chromosomes 1 and 3
Explanation:
There are four types of chromosomes classified based on the position of their centromere. These chromosomes are metacentric, submetacentric, acrocentric and telocentric. As rightly stated in this question, metacentric chromosome is the chromosome that has a centrally located centomere making the chromosome arms to be approximately of equal length.
The metacentric type of chromosomes are present in humans as viewed using KARYOTYPE (a pictorial display of chromosome arrangement). Based on karyotyping, chromosomes 1 and 3 are METACENTRIC.
What conditions must be ideal for an enzyme to function?
The conditions for an enzyme to work properly would be around a specific temperature & pH ranges.
Higher temperatures (heat) would speed up the functioning of the enzyme while lower temperatures (cold) would do the opposite..
A depiction of the MAPK/ERK signaling pathway that leads to cell growth is shown in the image.
What would be observed if a carcinogenic compound in coal tar activated step 3 of the pathway, even in the absence of the signaling molecule?
A) The transduction molecules in step 5 would always be active.
B) Step 2, the step linking the receptor to transduction, would always be active.
C) Step 4, a transduction step, would be prevented from activating the target protein.
D) The transcription factor in step 6 would be prevented from transcribing the target genes.
Answer:
a
Explanation:
I am pretty sure its a
which sentence best describes the process of drawing conclusions based on the information in table
Answer:
Conclusions, like inferences, involve educated guesses about what information means, beyond what is stated directly.
Explanation:
Hope this helps.
SOMEONE PLZ HELP ME!!!!!!!
Answer:
nucleus mitochondria ,
, lysosome i think
Explanation:
Answer:
A) nucleus
B) mitochondria
D) lysosomes
Explanation:
you can look at a diagram and find the differences
Which two pieces of equipment did the geologist most likely use to determine the density of the copper nuggets?
Which is greater 1,000 ml or 1,000 cm?
Answer:
Neither, they are equal.
1,000 cm3 = 1000 mL
Explain one way the water cyce affects weather.
Answer:Consequently, the temperature will fall. Rainfall and snow are results of water cycle and can lead to severe weather conditions. Excessive rainfall due to water cycle can cause floods. Extremely low rainfall, lack of adequate water sources can lead to draught in a given region.
Explanation:
Due to the higher concentration of oxygen (O2) in the air than your blood, oxygen goes from the lungs into the red blood cells by ... *
PLEASE HELP I WILL MARK BRAINLY
THANK YOU
Due to the higher concentration of oxygen in the air than your blood, oxygen goes from the lungs into the red blood cells by simple diffusion.
It should be noted that oxygen diffuses from the lungs into the red blood cells. It then binds to hemoglobin. A molecule of hemoglobin can bind with four molecules of oxygen.
Since the red blood cells have cell membranes that are thin, this then enables oxygen to be able to diffuse quickly.
In conclusion, the correct option is simple diffusion.
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How many cycles of β oxidation are required for the complete oxidation of activated oleic acid, 18:1(9)?
Answer:
The answer is "8 beta-oxidation cycles".
Explanation:
Please find the complete question in the attached file.
In this complete oxidation of active oleic acid 18:1(Δ9), 8 beta-oxidation cycles are required. Oleic acid is saturated fat, 9 to 10-carbohydrate fatty acid. Its double bonding is cis-focused. Its cycles for beta-oxidation required to oxidize an active oleic acid fully are 8.
It's initial two fatty acids are removed by oxidation in β - oxidation from the initial two carbon atoms. The recently formed carbon units are made up of creating temporary A molecules (acetyl- CoA). That cycle for oxidative begins with both the coffee grounds terminals of the fat lactone chain.
What effect does development, through erecting buildings and concrete pavement, have on the recharge of aquifers and the quality of the water?
Answer:
Infiltrate rate decreases and also water quality.
Explanation:
There is adverse effect of erecting buildings and concrete pavement on the recharge of aquifers and the quality of the water because the water is unable to infiltrate inside the soil due to concrete floor and the recharging of aquifers is not possible. These buildings and concrete pavements also reduces the quality of water due to degradation of sediments present in the building with the passage of time.
You and your friends go to the beach for vacation. You all walk down to the beach to go swimming. When you get there, you see the water is murky and green, and there are algae blooms floating on top. If it is excess nutrients which are feeding the algae blooms and lowering the oxygen content in the water, that process is called:_______.a. nutrient cycling.
b. nitrification.
c. eutrophication.
d. hypoxia.
Answer: The process is called EUTROPHICATION. The correct option is C.
Explanation:
Eutrophication is a type of environmental pollution where by there is an increase in nutrient salts of a water body which can lead to structural changes in the affected aquatic ecosystem. These changes includes:
--> Increase in production of algae: this effect causes algae blooms which makes the water murky, greenish and unpleasant for certain activities such as swimming.
--> Decrease in aquatic life: the presence of excessive growth of algae which are often degraded by microorganisms. When the rate of degradation of the algae by microorganisms is greater than that of oxygen regeneration a hypoxic state occurs which is harmful to aquatic life example fishes.
A(n) ________ is a procedure in which blocked heart vessels are opened physically by passing a catheter into the narrowed vessel.
Answer:
Angioplasty uses a balloon-tipped catheter to open a blocked blood vessel and improve blood flow.
Explanation:
10.
_________produces pollens and______
develops into the fruit.
Answer:
stamen produces pollen ovules develops into fruit
Explanation:
The region in a plant that is analogous to animal stem cells, and can develop into various types of tissues and organs, is the ______.
he root system includes those parts of the plant below ground, such as the roots, tubers, and rhizomes. Plant cells are formed at meristems, and then develop into cell types which are grouped into tissues
Which organelle makes energy for the animal cell?
A. mitochondria
B. chloroplasts
C. chromatin
D. golgi apparatus
Answer:
A. mitochondria
Explanation:
The mitochondria makes energy for the animal cell. The mitochondria organelle is known as the "power house of all cells". It makes energy for the cell.
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Which type of mining is likely the least harmful to the environment?
a. surface mining
b. placer mining
c. subsurface mining
d. none of the above
Answer:
Placer mining
Explanation:
Placer mining can be less damaging to the environment than surface mines, as the sediment is returned to the water after the minerals have been extracted.
The mining that is likely the least harmful to the environment is the placer mining that is present in Option B, water is used in placer mining to separate mineral particles from soil.
What is placer mining?Placer mining involves the extraction of minerals from riverbeds, streambeds, and other bodies of water, and this method involves the use of water to separate mineral particles from soil, while placer mining is generally considered to be less harmful to the environment compared to surface and subsurface mining, but it can still have negative impacts if not properly managed. For example, the use of mercury in the gold extraction process can lead to water pollution and harm to aquatic life.
Hence, the mining that is likely the least harmful to the environment is the placer mining that is present in Option B.
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In which state of matter do the particles move independently of one another?
A.amorphous solid
B.Gas
C.Crystalline solid
D.Liquid
Answer:
I Think Gas
The gaseous state has very loose and unorganized structuring of particles, making them have little attraction and move independently.