Water fleas (Cladocera) are small freshwater crustaceans. They are filter feeders can are about 3-5mm long. The outer carapace of a water flea is transparent so the internal organs can be observed. Caffeine raises the heart rate of humans. Hanna predicts caffeine will have the same effect on other organisms. She uses the water flea as her test subject in an experiment. Hanna introduces varying amounts of caffeine to water flea populations. Using a microscope, she measures the heart rate in beats per second of sample water fleas. She records the data in a table. As the concentration of caffeine increases, Hanna observes the water flea heart rate also increases. What is the hypothesis in Hanna’s experiment? A) Caffeine raises the heart rate of humans. B) Water fleas prefer caffeine over plain water. C) Caffeine increase the heart rate of the water flea. Eliminate D) The effects of caffeine are the same on all organisms.

Answers

Answer 1

Answer:

The Answer is C.

Explanation:

sorry i took awhile

Answer 2

The hypothesis is the part of the scientific method that is the supposition based on some observed data. In Hanna's experiment, "caffeine increase the heart rate of the water flea" is the hypothesis. Thus, option C is correct.

What is a hypothesis?

The hypothesis has been defined as the conjecture that is proposed in a scientific method and is based on the speculations from the observed facts and information. It is proposed to perform the experiment and reach the conclusion of the reliability.

They are testable and are performed through the experimental design that includes the experimental and control group so that the collected evidence can be analyzed and proved to be true. In Hanna's experiment, the effect of caffeine on the heart rate of fleas is a hypothesis.

It is a hypothesis as it is based on the observed fact that caffeine increases the human heart rate. The caffeine acted as the independent variable and the heartbeat was the dependent variable that showed that water fleas have increased heartbeat if given caffeine.

Therefore, option C. caffeine increases heartbeat is the hypothesis.

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Related Questions

Match the following examples to the correct type of bone marking. a shallow depression in the back of the knee joint openings in the cervical vertebrae through which the vertebral artery travels a depression on the skull that houses the frontal lobes of the brain a bony projection on the tibia, below the knee a hole created by bones of the pelvis

Answers

Answer:

1. Fossa....a shallow depression in the back of the knee joint

2.Foramen.....openings in the cervical vertebrae through which the vertebral artery travels

3. Fossa....a depression on the skull that houses the frontal lobes of the brain

4. Tubercle...a bony projection on the tibia, below the knee

5. Foramen....a hole created by bones of the pelvis

can anyone help me with the answer above? brainlist if you end up being correct

Answers

Answer:

Oligopoly

Explanation:

That's the answer

Answer:

Oligopoly

Explanation:

Which statement describes the focus of an earthquake?

Answers

Answer:

B. It develops in the lithosphere.

Explanation:

the other person was right :)

Answer:

B

Explanation:

Which of the following is not part of the circulatory system? Group of answer choices Heart lungs Blood Vessels Blood

Answers

Explanation:

Lungs is not a part of circulatory system as it is the part of respiratory system.

What do bones contain?

Answers

Answer:

Made mostly of collagen, bone is living, growing tissue. Collagen is a protein that provides a soft framework, and calcium phosphate is a mineral that adds strength and hardens the framework. This combination of collagen and calcium makes bone strong and flexible enough to withstand stress.

Explanation:

hope that helps

Answer:

Bones contain a soft tissue called marrow.

Explanation:

edge 2021

If you formed a protein that was 100 amino acids in length, how many water molecules would
be removed?

Answers

50 water molecules would be removed

Answer:

50 molecules

Explanation:

Divide the number by 2.

100 ÷ 2 = 50.

50 molecules must be removed.

What challenges cell biologists face in the 21st century?

Answers

Answer:

There are many types of challenges are faced by the scientists in 21st century. some are as given below:

Explanation:

1. Getting biodiversity. We're losing species at a disturbing rate, and we have to comprehend what the implications of that may be.  

2. sustainable development. Like feasible agriculture, yet more broad sense. Discovering approaches to accommodate human needs while limiting the mischief we cause to the earth is urgent.  

3. Everything about hereditary qualities. It's simply so much fun.  

4. The most effective method to cut across political, social, and social limits and spur enormous and little scope activity to lessen biodiversity loss. This point may have a hefty sociology component, yet it's significant. All the natural and biological information on the planet won't make any difference on the off chance that we can't get individuals to follow up on it.

. Name the cells that are produced by the testes and ovaries.

Answers

Answer and explanation:

In the female of the species the reproductive cells are the egg cells, and in the male the reproductive cells are the sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. The testes contain germ cells that differentiate into mature spermatozoa, supporting cells called Sertoli cells, and testosterone-producing cells called Leydig (interstitial) cells.

Certain kinds of shells are always found in rock layers lower than layers with plant fossils. Dinosaur fossils show up only in layers above or with plant fossils what does this tell you about When these organisms lived

Answers

Answer:

This shows that once animals were on the surface there were plants for them to eat.

Dinosaur fossils show up only in layers above or with plant fossils. This shows that dinosaurs were animals that lived with plants and feed on plants.

What are fossils?

Fossils are the remains of plants, animals, and other substances that are preserved under the layers of rocks and earth. They are the preserved form that gives the knowledge of organism present in before times.

Dinosaurs lived 65 million years ago, but still, their bones and remains are found on earth. They were found with the fossils of plants, so this tells us that plants were also present at the time of their presence, and they fed on plants.

Thus, only strata above or in conjunction with plant fossils do dinosaur fossils appear. This demonstrates that dinosaurs were also plant-eating and lived with plants.

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what does an antibiotic treat?​

Answers

Answer:

Explanation:

Antibiotics are strong medicines that treat bacterial infections. Antibiotics won't treat viral infections because they can't kill viruses. You'll get better when the viral infection has run its course. Common illnesses caused by bacteria are urinary tract infections, strep throat, and some pneumonia.

Answer:

Antibiotics are strong medicines that treat bacterial infections.

Explanation:

what would happen if organisms did not have enzymes?

Answers

Digestive enzymes speedup reactions that break down large molecules of carbohydrates, proteins, and fats into smaller molecules the body can use. Without digestive enzymes, animals would not be able to break down food molecules quickly enough to provide the energy and nutrients they need to survive.

This is a molecule of glucose, a simple carbohydrate. If this molecule were broken down, would it provide all of the elements needed to assemble lipids, nucleic acids, or proteins? Use evidence from the diagram in your answer.

Answers

Answer:

The correct answer is - no.

Explanation:

Carbohydrates are made up of thee elements carbon, hydrogen, and oxygen so if the carbohydrate is completely broken down it will release these elements.

Lipids are made up of similar elements as glucose however, they also contain sulfur and phosphorus. Similarly for proteins and nucleic acid nitrogen, nitrogen sulfur, and selenium other than the elements released by glucose.

Thus, the correct answer would be - no.

organs in different animal locomotion​

Answers

Answer:

cilia, legs, wings, arms, fins, or tails are sometimes referred to as locomotory organs or locomotory structures.

hope this helped you

please mark as the brainliest (ㆁωㆁ)

What happens to a watershed if it rains

Answers

Answer:eh water could either be drained into the soil or land on plants to become dew

Explanation:i searched up what a watershed was lol

d4 Science)
7. Where do you find membrane-bound organelles?

Answers

Eukaryotic cells contain many membrane-bound organelles. An organelle is an organized and specialized structure within a living cell. The organelles include the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, vacuoles, lysosomes, mitochondria, and, in plants, chloroplasts

The process by which molecules such as glucose are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called The process by which molecules such as glucose are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called

Answers

Answer:

Facilitated diffusion

Explanation

Generally when molecules undergo passive diffusion along their concentration gradient,and aided by the cell membrane which provide hydrophillic areas for the molecules to pass through,this is called  facilitate the diffusion.The membrane would be impermeable to these molecules without the proteins,

It is a special transport mechanism for large molecular substances like glucose and Amino acids and ions  e.g Na+ and K+.Therefore facilitated mean to aid,thus the membrane proteins aids or help molecules to pass through.

Channel protein and carrier proteins are the two type of protein involved in the transport.They are specific for each molecules,and would only allow the passage of one molecule or ion through.

Energy is not needed for this to occur place the molecules of glucose are moving along the concentration gradient.

Specifically channel proteins are fixed in shape,some are gated.They are water filled pores Carrier proteins are flexible and adjust their shape to the two media for transport.Thus if the concentration of substances to be transported i s higher on on side A of the cell membrane proteins,the carrier protein will be open to  that side to convey the molecules across.

The amount of molecules transported depend on the amount of the  carries and channel protein available.

What advantages do diatoms obtain from sexual reproduction?a. increased genetic variability.b. increased ability of populations to respond to environmental change.c. evolutionary potential.d. regeneration of maximal cell size for the species.d. all of the above.

Answers

Answer:

The correct answer is: option D. all of the above.

Explanation:

In sexual reproduction, two opposite gender gametes are fused together to form a zygote by the process called fertilization which forms the new organism that is genetically unique.

In diatoms, sexual reproduction caused various types of advantages such as higher or enhanced genetic variability as recombination occurs. It also helps the ability to responding to environmental change Increasing the population or species size and other.

Thus, the correct answer is: option D. all of the above.

By what factor (how much) does the milli- unit differ from the centi- unit?
earth science

Answers

Answer:

By a factor of 0.1.

Explanation:

Hello,

In this case, since the milli- unit has a factor 0.001 and the centi- unit a factor of 0.01 we can apply the following division in order to compute by what factor they actually differ from:

[tex]\frac{milli}{centi}= \frac{0.001}{0.01} =0.1[/tex]

It means that the milli- unit differ from the centi- unit by a factor of 0.1. Conversely, the centi- unit differ from the milli- unit by a factor of 10:

[tex]\frac{centi}{milli}= \frac{0.01}{0.001} =10[/tex]

Regards.

Who is known as the "father of modern chemistry" because he first organized all known elements into four different groups?
A. Johann Wolfgang Döbereiner
B. Antoine Lavoisier
C. Dmitri Mendeleev
D. Henry Moseley

Answers

Answer:

The answer is D, Henry Moseley.

Explanation: I took the quiz and scored 100%, so I'm certain this is accurate.

Answer:

Henry Moseley

Explanation:

The blood-brain barrier (BBB) is most permeable to which of the following?
A. Platelets, white blood cells and red blood cells.
B. Sodium, potassium and chloride.
C. Glucose and oxygen.
D. Antibiotics.

Answers

Answer:

C. Glucose and oxygen.

Explanation:

The blood-brain barrier is a composition of endothelial cells that regulate the entry of substances into the extracellular fluid found in the central nervous system. Their high degree of selective permeability ensures that no solutes can cross the barrier, and only the right substances which are crucial to the workings of the central nervous system can scale through.

Oxygen which is needed for the proper functioning of the central nervous system and which is hydrophobic in nature is allowed to pass the blood-brain barrier. Glucose too which is an important nutrient/macromolecule for brain health can also move through the blood-brain barrier.

Explain how passive and active transport are similar and how they are different.

Answers

Answer:

Active transport moves molecules and ions from lower concentration to higher concentration with the help of energy in the form of ATP. On the other hand, passive transport moves molecules and ions from a higher concentration to lower concentration without any energy.

Explanation:

Answer:Active transport moves molecules and ions from lower concentration to higher concentration with the help of energy in the form of ATP. On the other hand, passive transport moves molecules and ions from a higher concentration to lower concentration without any energy.

Explanation:

what do you think the difference between simple and complex carbohydrates is?

Answers

Answer:

Complex carbohydrates are present in foods such as bread and pasta. Simple carbohydrates are in foods such as table sugar and syrups. Complex carbohydrates contain longer chains of sugar molecules than simple carbohydrates. The body converts these sugar molecules into glucose, which it uses for energy.

Explanation:

Hope that helps!



How many extrinsic eye muscles control each eye in a cow?
O 12
06
O 5
O4

Answers

Answer:

Cows have 4 extrinsic eye muscles that control each eye in a cow. They can look up, down, left, and right, but they can't roll their eyes as you can.

4 is the answer.........

Why is a steam burn more severe than a hot water burn?

Answers

Answer:

Steam burns are more severe because of the latent heat of vaporization.

Diagram a motion graph of a bicycle that travels 80 meters in 16 seconds. What is the speed in meters/second?

Answers

Answer:

50

Explanation:


A scientist wants to test whether the pH, salinity, or temperature of seawater impacts coral
development. He sets up an experiment with three conditions:
Aquarium 1: Normal pH, normal salinity, normal temperature
Aquarium 2: High pH, high salinity, high temperature
Aquarium 3: Low pH, low salinity, low temperature
What factor would improve experimental design the most?

Eliminating Aquarium 1 since it only uses normal conditions

Testing one variable at a time and keeping the other two variables constant

Using one aquarium and changing the variables from day to day

Setting up the variables on a gradient in each aquarium

Answers

Answer: Testing one variable at a time and keeping the other two variables constant

Question 6
How many
extrinsic eye muscles control each eye in a cow?
O 12
6
O 5
4

Answers

Answer:

12 jdjdjmrmrkkdmmuscles

Answer:

4

Explanation:

Cows have only four muscles that control their eyes. They can look up, down, left, and right, but they can't roll their eyes like you can.

A cell membrane is very specific about what it allows across. How does t help the cell? ​

Answers

Answer:

Explanation:

The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates the interior of all cells from the outside environment (the extracellular space) which protects the cell from its environment.[1][2] The cell membrane consists of a lipid bilayer, including cholesterols (a lipid component) that sit between phospholipids to maintain their fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that go across the membrane serving as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes shaping the cell.[3] The cell membrane controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules.[4] In addition, cell membranes are involved in a variety of cellular processes such as cell adhesion, ion conductivity and cell signalling and serve as the attachment surface for several extracellular structures, including the cell wall, the carbohydrate layer called the glycocalyx, and the intracellular network of protein fibers called the cytoskeleton. In the field of synthetic biology, cell membranes can be artificially reassembled

Why do scientists classify organisms?

To more easily sequence their genetic material

To create scientific names that only scientists can learn

To have common names that everyone can remember

To organize them and speak about them accurately

Answers

Answer:

To organize them and speak about them accurately

Answer:

d

Explanation:

edge 2022

Which of the following is the Earth's largest reservoir of carbon dioxide?
atmosphere
icebergs
oceans
O soil

Answers

The first one ........
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