why do veins have valves

Answers

Answer 1
Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don't require valves because pressure from the heart is so strong that blood is only able to flow in one direction.) Valves also help blood travel back to the heart against the force of gravity.

Related Questions

Which of the following is NOT a factor of sustainability?
Group of answer choices

economics

ethics

biodiversity

natural capital

solar energy

Answers

Answer:

natural capital

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PLS MARK AS BRAINLIEST!!!

When an outbreak of foot and mouth disease is discovered among livestock in a country, what is MOST likely the chosen way to control it?

Answers

Answer:

You can get infected with hand, foot, and mouth disease if you have the virus on your hands and then touch your eyes, nose, or mouth. To lessen your chance of getting sick, don't touch your eyes, nose, and mouth with unwashed hands.

You can get infected with hand, foot, and mouth disease if you have the virus on your hands and then touch your eyes, nose, or mouth. To lessen your chance of getting sick, don't touch your eyes, nose, and mouth with unwashed hands.

What are the mechanism that use to resist the antimicrobial agents?

There has been several mechanisms, like resistance to antimicrobial agents, encapsulation or secretation of proteins that affects and might destroy the phagocyte along with some leukocytes in our body perform phagocytosis as a defense mechanism against the pathogenic bacterium.

These phagocytes contain lysosomes, intracellular granules that possess bactericidal substances. When the phagocyte ingests the pathogen, a phagosome is formed, which merges with the lysosome, forming the phagolysosome, which is where toxic substances and enzymes kill the ingested microorganism.

There are several mechanisms by which a microorganism can survive this process as resistance to antimicrobial agents. Some bacteria use phenolic glycolipids from their cell wall, to eliminate toxic oxygen compounds.

Therefore, You can get infected with hand, foot, and mouth disease if you have the virus on your hands and then touch your eyes, nose, or mouth.

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Could an object, tool, or structure be made without the use of a natural resource? Explain your answer.

Answers

Bajamapa alsnbcian. Sin. A

What is the valence of an atom with six electrons in its outer electron shell?
A)1
B) 2
C) 3
D) 4
E) 5

Answers

Answer:

D. Valency is 4

Explanation:

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Non segmentation allows for evolutionary innovation in body form. True or false

Answers

Answer:

True

Explanation:

Choose a strategy to clone genes known only by a mutant phenotype in organisms with highly efficient transformation procedures and relatively small genomes.
a. cloning by complementation
b. direct sequencing of the mutant genome
c. PCR of the gene and transformation of an organism
d. cloning using a specific cloning vector

Answers

Answer:

Option a (cloning by complementation) `would be the correct choice.

Explanation:

In species containing extremely efficient transforming techniques as well as comparatively small genomes, cloning by rearrangement testing is performed to clone gene products mostly by a mutated gene as the rearrangement test was being used to detect mutations.This strategy for cloning through mechanism begins with identifying another yeast mutant that affects something like a plasmid representing a cloned genetic material.

The other options in question aren't relevant to the particular circumstance. Therefore the answer to the above seems to be the right one.

What is the retrovirus, and how does it work? Name an example of a retrovirus.

Answers

Answer:

A retrovirus is a type of RNA virus that inserts a clone of its genome into the DNA of a host cell that it invades. An example of a retrovirus would be HIV.

Hope this helps! :)

Explanation:

A retrovirus is a specific kind of RNA virus that, when it infects a host cell, will insert a clone of its genome into the DNA of the host cell. HIV is an example of a retrovirus that may infect humans.

What is a retrovirus?

A kind of RNA virus known as a retrovirus copies its genome into the DNA of the host cell it invades. HIV is a prime example of a retrovirus.

A virus that employs RNA as its genetic material is referred to as a retrovirus. When a cell becomes infected with a retrovirus, the retroviral RNA is converted to retroviral DNA, which is then inserted into the DNA of the host cell.

Acute retroviral syndrome symptoms, which include headache, nausea, diarrhoea, and body pains, are comparable to those of the flu and go away on their own in a few of weeks. A person who has acute retroviral syndrome may no longer have any symptoms, yet they are nonetheless HIV-positive and remain contagious.

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What sections of DNA are used in DNA fingerprinting?
O A. Sections that only contain mRNA
O B. Sections that are unique to each person
O c. Sections that have the fewest mutations
O D. Sections that are made by bacteria

Answers

The correct answer is B

Economic importance of Angiosperm and Gynosperm

Answers

Answer:

Angiosperms

1. Production of fruits

2. The plants serve as a source of pharmaceuticals.

3. They also serve as a source of fiber products.

4. Source of timber.

5. Source of ornamentals.

Gymnosperms

1. Production of lumber.

2. Source of seeds of ginko, pinus, cycas, etc.

3. Paper production.

4. Resin production.

5. Soap production.

6. Varnish production.

7. Nail polish production.

8. Gum production.

9. Perfume production.

What is a biological approach to determining when a mother and her conceptus become separate individuals?

Answers

Answer:

Electroencephalography.

Explanation:

Electroencephalography is used to measure brain activity in terms of electrical activity. It is done by attaching electrodes on the scalp, or sometimes by placing electrodes directly in the brain. Using electroencephalography can help determine when the fetus starts having its own brain activities, which means that it is now a separate entity distinguishable from its mother. Using electroencephalography to see brain waves can give us a deeper insight into the age old complicated issue of when a mother and her conceptus become separate individuals.

HELPPPPP Which of the following pieces of evidence supports that species change due to certain genetic variations? Darwin's theory of evolution was incorrect, as it did not account for variation in a species. Natural selection causes variation but cannot cause the evolution of a new species. Mutation and natural selection both cause changes in a population. Changes in a population abruptly occur as a direct response to the environment.

Answers

Answer:

D. Mutation and natural selection both cause changes in a population

Explanation:

I just took the test. Good luck! :)

The two evidences that supports the fact that species change due to certain genetic variations are that mutation and natural selection both cause changes in a population.

What is natural selection?

Natural selection is the postulation by Charles Darwin that organisms that are more adapted to their environment live longer and reproduce hence pass on their favorable traits to their offspring.

The two evidences that supports the fact that species change due to certain genetic variations are that mutation and natural selection both cause changes in a population.

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The levels of nitrogen and ___ in the atmosphere remain fairly constant but the levels of other gases may vary.

Answers

Answer:Oxygen

Explanation:

What type of system is used to move the body?

Answers

The skeletons system
Skeletons system I’m pretty sure

What is the metaphor for been weevil

Answers

Answer:

The scarab or dung-beetle, and the spider to some ancient symbologists

List some Characteristic of fruits.​

Answers

Answer:

Quality factors for fruits include the following— maturity, firmness, the uniformity of size and shape, the absence of defects, skin and flesh color. Many of the same quality factors are described for vegetables, with the addition of texture-related attributes such as turgidity, toughness, and tenderness.

Oxygen is produced.
Select one:
O a. Both Photosynthesis and Cellular Respiration
b. Photosynthesis
c. Cellular Respiration
d. Neither Photosynthesis nor Cellular Respiration

Answers

Answer:

b.Photosynthesis

Explanation:

as plants produce 02 in the presence of light

Answer:

Option(B):Photosynthesis

Explanation:

Cellular respiration, the process by which organisms combine oxygen with molecules,

in photosynthesis oxygen is produced

when would a recessive trait be seen in an organism? A. When there is one dominant and one recessive gene for the trait present in the offspring. B. When there are two dominant genes for the trait present in the offspirng. C. When there are two recessive genes for the trait present in the offspring D. Never

Answers

A when there’s one dominant and one recessive gene for the trait present in the offspring

Taxonomists today tend to group organisms into the same category based on similar what?

Answers

Answer:

characteristics

Explanation:

oranisms are grouped based on shared characteristics

Taxonomists today tend to group organisms into the same category based on their evolutionary history and shared ancestry, as explained in Option A, as this allows taxonomists to construct more accurate and detailed phylogenetic trees.

What is taxonomy?

The field of taxonomy is concerned with the classification of living organisms based on their shared characteristics, the aim of taxonomy is to group organisms in a way that reflects their evolutionary history and to provide a standardized system of naming, while earlier taxonomists relied on morphological characteristics, such as the physical appearance of an organism, but modern taxonomists instead use molecular and genetic data to group organisms into categories.

Hence, taxonomists today tend to group organisms into the same category based on their evolutionary histories and shared ancestry, as explained in Option A.

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The question is incomplete, complete question is below

Taxonomists today tend to group organisms into the same category based on similar what?

A)based on their evolutionary histories and shared ancestry

B)based on fossils

Which is biotic?
O water
O temperature
beeswax
rocks​

Answers

Beeswax because it is a livong thing

The biotic factor among the options given is beeswax, which is the third option, as the biotic factors are living or once-living organisms in an ecosystem that directly or indirectly affect other organisms.

What is a "biotic factor"?

Biotic factors are living or once-living components of an ecosystem that have a direct or indirect effect on the survival, growth, and reproduction of other living organisms. Examples of biotic factors include plants, animals, fungi, bacteria, and other microorganisms that are part of the ecosystem. Beeswax, as mentioned, is a biotic factor because it is produced by living organisms, specifically bees. Beeswax is used by bees to build their hives or nests, which are important structures for their survival and reproduction.

Hence, the biotic factor among the options given is beeswax, which is the third option.

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Explain in detail if the water molecule (top) can interact with the glucose molecule (bottom)

Answers

Answer:

Yes, glucose dissolves in water.

Explanation:

Hello,

In this case, we can state that glucose is largely soluble in water due to the fact that it has five of polar hydroxyl groups which can interact with the hydrogen atoms in the water throughout the hydrogen bonds. Such hydrogen bond is known as an intermolecular force that forms a special type of dipole-dipole attraction when a hydrogen atom bonded to a strongly electronegative atom (like the oxygen in the hydroxyl groups) exists in the vicinity of another electronegative atom with a lone pair of electrons, therefore they occur among molecules.

which type of soil is likely to be found in horizon E

Answers

Answer:

A layer of pale,Sandy soil lacking clay and iron is likely to be found in horizon E

Answer:

bedrock

Explanation: A layer or bedrock is the type of soil is likely to be found in horizon E. Hence the correct answer is option A among the options. The bed rocks can be regarded very hard and it cannot be breakable.

A student hypothesized that EC growth might be affected by the DNA from circulating erythrocytes. Is this student’s hypothesis reasonable?

Answers

Answer:

Explanation:

It can be said that this hypothesis is actually not reasonable because circulating erythrocytes do not contain DNA. This can be proven by the Mammalian erythrocytes (rbcs) which ultimately loose their nuclei as well as many other organelles during their maturation process and they don't have nuclei or mitochondria meaning that they are not affected by the DNA.

HELP!!!

1. In a parent pea plant with the allele pair Gg, what is the probability that one gamete will contain the G allele? Why?
2. In a parent pea plant with the allele pair GG, what is the probability that one gamete will contain the g allele? Why?
3. In a parent pea plant with the allele pair gg, what is the probability that one gamete will contain the g allele? Why?

Answers

Answer:

If the gamete will get either G or g, the probability will be 1/2 of getting G.

Explanation:

all question 3 answer is that. Because all 3 of question are same. only repeated three times

In a parent pea plant with the allele pair Gg, the probability that one gamete will contain the G allele is 0.5. This is because there are two possible outcomes in which one must definitely fall. So, it is 1/2.

What is Allele?

Alleles may be characterized as the alternative form or versions of a gene that are responsible for particular traits in living organisms. They carry a code of genetic sequences within generations.

In a parent pea plant with the allele pair GG, the probability that the gamete will contain the g allele is zero. This is because there is no presence of allele g that can be determined within any gametes. So, it is not possible to get g in the pair allele of GG.

In a parent pea plant with the allele pair gg, the probability that one gamete will contain the g allele is 1 or 100%. This is because both carry g alleles. So, the probability is 100%.

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Some people use the terms "cell cycle" and "mitosis" as if they were the same thing. Which of these best describes why they are not the same?

a. the cell cycle is just a stage of mitosis
b. mitosis and the cell cycle are different types of cell division that occur in different of cells in a multicellular organism
c. mitosis is a sequence of events within the cell cycle that separates the genetic material
d. mitosis is a type of cell division that occurs in eukaryots and the cell cycle takes place in prokaryots

Answers

Answer: C. Cells in meiosis have unique genetic information

Explanation: Meiosis is the cell division that forms four daughter cells from one parent cell. It includes two successive divisions called as meiosis I and meiosis II. Crossing over during prophase I of meiosis I imparts new gene combinations to the daughter cells of meiosis. Hence, daughter cells formed by the end of meiosis have some new gene combinations, that is, unique genetic information.

From a population of red, brown, orange, yellow, and green butterflies, only the red and green ones survive since they can blend into their environment and reduce predation. Which evolutionary mechanism is involved?

Answers

Answer:

Natural Selection

Explanation:

Since the other species don't survive naturally, the red and green ones continue to breed so that their species will continue to live.

A purebred tall pea plant is cross-pollinated with a tall, can you please help
heterozygous pea plant. Use a Punnett square to determine the probability the offspring inherita
recessive short allele. (I point)
75%
25%
0%
50%

Answers

Answer:

50%

Explanation:

because if you use the box method you see that half receive a short alele

   T     t

T TT  Tt

T TT   Tt

What is the ratio of surface area to volume for a sphere with the following measurements. Surface area = 432m2, volume = 864m3

Answers

Answer:

the ratio of the surface area to the volume is 1:2

Reaching for your coffee cup is accomplished by the _____ subdivision of the peripheral nervous system.

Answers

Answer:

somatic subdivision

Explanation:

The peripheral nervous system is divided into somatic and autonomic systems. The somatic system is required to transport sensory and motor information to the central nervous system. The somatic system is composed of nerves that connect different parts of the body including sensory fibers, skin, and skeletal muscles. On the other hand, the autonomic system can be subsequently classified into sympathetic and parasympathetic systems, which are required in fight (potentially dangerous) and calm-associated responses, respectively.

When you touch an object that is very hot you quickly pull your hand back.
What is the correct pathway of nerve impulses for this behavior?

Answers

Answer:

this is called reflect action

Answer:

reflex action

Explanation:

this is because, it makes it possible to swiftly pull back your hand if you accidentally touch a hot pan

What energy transformations are going on within the skateboarder’s body during this process?

Answers

Answer:

When they slide down, they lose this potential energy, which turns into kinetic energy and thermal energy. Thermal Energy - This energy is related to the temperature of a body or a system. When friction is involved in a system, part of the kinetic energy is transformed into thermal energy.

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A mass M is attached to an ideal massless spring. When this system is set in motion with amplitude A, it has a period T. What is the period if the amplitude of the motion is doubled Triangle L J K is shown. Angle J L K is a right angle. The length of the hypotenuse is 15 inches and the length of the side adjacent to the right angle is 10 inches. The angle between the 2 sides is x. Which equation can be used to find the measure of angle LJK? sin(x) = Ten-fifteenths sin(x) = Fifteen-tenths cos(x) = Ten-fifteenths cos(x) = Fifteen-tenths Buckson Framing's cost formula for its supplies cost is $1,350 per month plus $18 per frame. For the month of June, the company planned for activity of 716 frames, but the actual level of activity was 713 frames. The actual supplies cost for the month was $14,820. The supplies cost in the flexible budget for June would be closest to: Find the value of x in the triangle shown below.(not a test just need help with khan academy) The small object in the picture is an artifact from Anglo-Saxon England. What do you think this object might be? Determine whether each equation has one solution, no solution or infinitely many solutions. 4x + 10 = 2(2x + 5) 4x - 5 = 4x + 10 4x - 5 = -5 write as an inequality 9 is greater than or equal to w, and -7 is less than or equal to w 4. What is harder for the astronomer to measure: A galaxy's redshift (indicating recessional velocity) or its distance from Earth? Why? Explain your answer. Name the following alkane molecule:CH3|CH3CHCH2CHCH2CHCH3CHCH2CH2CH3A. 2,4,6-trimethylheptaneB. 4-ethyl-2,6-dimethylheptaneC. 2,6-dimethyl-4-propylheptane what is the drug delivery system for alka seltzer in a 41-49 right triangle, the hypotenuse is 28.83 centimeters. if cos 41= 0.7547, find the length of the side opposite the 49 angle. Estimate your answer to three decimal places Solve for x.5(2x 5) 2 1= -12 Sequence three probable steps of fossil fish formation? Word problems ! Please help A shopkeeper sells a DVD player at a price RM 2,500. If the cost price of the DVD player was RM 3,500, find the profit/loss in which the shopkeeper is. Also, find the percent for the same. Regulation SHO:________. I. requires every sell order to be marked either ""long sale"" or ""short sale"" II. requires every buy order to be marked either ""long purchase"" or ""short purchase"" III. places limits on ""naked"" short sales of equity securities IV. places limits on ""covered"" short sales of equity securities" Find the surface area of the composite figure What percentage is 420 grams of 750 grams?% PLEASE FIND THE ANSWER FOR B.) How many times more ?