An experiment was designed to investigate the effect of caffeine on the heartbeat of Daphnia magna, or water fleas. These tiny, aquatic animals are used because their transparent bodies make it easy to see their hearts and measure their heart rates. Two populations of Daphnia were raised, (A) and (B). Both populations lived in tanks of water at the same temperature and received identical amounts of food. Every 2 hours, water fleas from both populations were selected and their heartbeats were monitored. Population (A) had 0.5 g of caffeine given to them five minutes before their heartbeat was checked. Population (B) were given 0.5 g of water and with no caffeine.

Answers

Answer 1

Answer:

This question is incomplete. It is asking to identify the following in the experiment:

Independent variable: CAFFEINE

Dependent variable: HEARTBEAT

Experimental group: POPULATION A, which were given 0.5g of caffeine

Control group: POPULATION B, which were not given caffeine

Constants: SAME TEMPERATURE, SAME AMOUNT OF FOOD, SAME TIME BEFORE CHECKING

Explanation:

Independent variable in an experiment is the variable which is changed or manipulated by the experiment. In this experiment, the independent variable is the CAFFEINE.

Dependent variable is the variable that is measured by the experiment or in other words, the variable that responds to changes made to the independent variable. In this experiment, the dependent variable is the HEARTBEAT measured.

The experimental group of an experiment is the group that receives the experimental treatment (caffeine). In this experiment, the POPULATION A of Daphnia magna, or water fleas are the experimental group because they received 0.5g of caffeine.

On the other hand, the control group is the group that does not receive the experimental treatment. In this experiment, POPULATION B did not receive any caffeine, hence, it is the CONTROL GROUP.

Constant or controlled variable are those variables that the experimenter must keep unchanged for all groups throughout the experiment, in order not to influence the experiment's outcome. In this experiment, the constants are: SAME TEMPERATURE, SAME AMOUNT OF FOOD, SAME TIME BEFORE CHECKING (2hrs)


Related Questions

Directions: Part 2 - Write your own skin scenario with FIVE or more sentences, using a completely different scenario than your 1st answer.
Describe TWO ways each skin layer is at work in your scenario.

Part 2 (10 Points) This scenario will be completely DIFFERENT than your original one. Write your own skin scenario here
(5 points)​

Answers

Answer:

For exampel when a person is working outside there skin helps them stay cool also if a person has a dark pigmentation they are less likely to get burnd by the sun as a light pigmentated person.

Explanation:

Part1: Compare the relative concentrations (amount of GtC) of at least six (6) components of the carbon cycle

(e.g. The ____ has less GtC carbon than the ______ .)

Part 2: Explain how the total amount of matter is conserved during the carbon cycle.

hint-the earth is a closed system

Answers

Answer:

Explanation:

PART 2 : The Law of Conservation of Matter states that matter cannot be created or destroyed.  The carbon cycle is an example of the Law because the same carbon atoms are being recycled through the carbon cycle.

Because elements are neither created nor destroyed under normal circumstances, individual atoms that compose living organisms have long histories as they cycle through the biosphere. In this depiction, a carbon atom moves from coal buried beneath the Earth's surface to a power plant and into the atmosphere. It eventually dissolves in water and is taken up by an algal cell, where it is then consumed by a copepod.

Compare and contrast between a human and an alligator life cycle.

Answers

Answer:

The human body constantly develops and changes throughout the human life cycle, and food provides the fuel for those changes. The major stages of the human lifecycle include pregnancy, infancy, the toddler years, childhood, puberty, older adolescence, adulthood, middle age, and the senior years.

where as,

Growth depends greatly on the surrounding environment, including temperature, and sexual maturity is reached at approximately 6 feet long. The life span varies greatly for these large reptiles, averaging 35 to 50 years for wildalligators and 60 to 70 years for crocodiles.

Explanation:

please mark as brainlist answers

how does the amount of precipitation affect the tundra and tropical rain forest species​?​

Answers

The amount of precipitation affects the number of species due to water being a primary resource for survival of all living organisms.

what does it mean by "outline the role" in biology?

Answers

Answer:Tell the function of the labeled thing.

Explanation:

Answer: tell the function of the labeled thingy.
Explanation: none

Why do scientists use the International System of Units (SI)?

A. because the SI is based on the metric system

B. because the tools scientists use only measure in SI units

C. so they can communicate their results without confusion

D. so all scientists are guaranteed to come up with the same measurements
PLEASE HELP

Answers

C- they need to know how to communicate with others so now they have a mechanism

In the carbon cycle, in what form are carbon atoms generally returned to the atomosphere? carbon dioxide b carbon monoxide simple sugars methane​

Answers

Answer:

The carbon cycle is a process where carbon is removed and returned to the atmosphere. The ways of returning carbon to the atmosphere

Explanation:

what type of cell transport does not require energy​

Answers

passive transport does not require energy

Answer:

Passive Transport

Explanation:

Examples of passive transport-

diffusion of oxygen and carbon dioxide, osmosis of water, facilitated diffusion.

Which of the following groups of organisms uses sunlight to convert carbon dioxide and water into sugar and oxygen?

a. producers
b. decomposers
c. carnivores
d. herbivores

Answers

The answer that you are looking for is: A PRODUCERS

The group of organisms which uses sunlight to convert carbon dioxide and water into sugar and oxygen are producers. Thus, the correct option is A.

What are Producers in the ecosystem?

Producers are any kind of green plants present in the ecosystem. Green plants make their own food by using the sunlight (solar energy) and carbon dioxide gas from the atmosphere with the energy to make sugar. The plant uses this sugar (carbohydrate), also called as glucose to make many different products, such as wood, leaves, roots, and bark.

This process through which plants produce their food is called photosynthesis. Photosynthesis occurs only in the plants which have chlorophyll pigment (chloroplast).

Therefore, the correct option is A.

Learn more about Ecosystem here:

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Cold air is more ________________, so it sinks
a. expanded (Will Give Brainiest!)

b. hot
c. dense

d. volume

Answers

Answer:

Dense, it falls because it is more dense then warmer air

Explanation:

1. An environment can support only as many organisms
as the available energy, minerals, and oxygen will
allow. Which term is best described by this statement?
A) homeostatic control
B) carrying capacity
C) biological feedback
D) biological diversity

Answers

Answer:

The answer is carrying capacity

Explanation:

Had a test

An environment can support only as many organisms as the available energy, minerals, and oxygen will allow. The term  best described by Carrying capacity

Carrying Capacity

It is the average population density or population size of a species below which its number tend to increase and above which its number tend to decrease because of shortage of resources. The carrying capacity is different for each species in a habitat because of that species particular food, shelter, and social requirements.

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Will award 70 points!
Calculate the rate of photosynthesis(mm/hr) for Elodea if when measuring net photosynthesis, the water level moved up 5 min and, when measuring cellular respiration it took 20 minutes for the water level to move down 1mm.
63mm/hr
57mm/hr
67mm/hr
61mm/hr
52mm/hr

Answers

Answer:

Net photosynthesis- 3mm/20min- 1.5mm/10min

Cellular respiration- 1mm/15min- 0.66mm/10min

Gross photosynthesis = Net photosynthesis + Cellular respiration = 1.5+0.66 = 2.16 (mm/10min)

Rate of photosynthesis = (gross photosynthesis)6 = 2.16 *6 = 12.96 mm/hr

As we are measuring rate of photosynthesis in hr ,we should multiply gross photosynthesis with 6 (as we measured gross photosynthesis for 10 min).

Explanation:

Astronomy is the study of

Answers

Answer:

Astronomy is the study of celestial objects. In other words, the study of anything having to do with the things of outer space.

Explanation:

The word astronomy comes from a Greek word that means "star-arranging."

Answer:

Astronomy is the study of the Universe

Explanation:

Hope this helps out

What is the process that uses energy to construct molecules?

Answers

Answer:

NADH via energy pathways including photosynthesis, glycolysis, the citric acid cycle, and oxidative phosphorylation

Explanation:

A lentil plant with spotted seeds was crossed with another that had dotted seeds. The F1 plants turned out to have seeds that had spots and dots. What could be the reason?

Answers

Answer:

Lentil seed pattern is affected by codominance.

Explanation:

Lentil seed pattern is affected by codominance.

Tissues are composed of groups of:
A.
unicellular organisms.
B.
specialized cells.
C.
specialized organs.
D.
organisms.

Answers

Answer:

B

Explanation:

Tissues are made up of specialised cells

B tissues are made of specialized cells

HELP HELP PLEASE!!!!!!!

Answers

Explanation:

Issen Sengeki... Messatsu!

The answer is 2.

"Weakness is a disease... I am the cure! When I walk, I walk alone. When I fight, I fight alone. The path of a weak coward is into the bowels of hell! Death is the only destination for life. Better die a free brave man."

- Akuma

Which of the following animals is raised on prairie land today?
sheep
owls
bison
deer

Answers

Answer:

The following animal that is raised on prairie land today I believe is the bison :)

The animal that is raised on prairie land today is sheep. The correct option is A.

What is prairie land?

Large expanses of grassland that are level or undulating are known as prairies.

These grasslands can be found in Minnesota in a variety of habitats, including shortgrass prairies perched high on the bluffs of the Minnesota River, enormous fields of big bluestem up to 8 feet tall, and sparsely vegetated sand dunes.

The Great Plains are made up of the Canadian provinces of Alberta, Manitoba, and Saskatchewan as well as the American states of North Dakota, South Dakota, Montana, Nebraska, Kansas, Oklahoma, Texas, Wyoming, Colorado, and New Mexico.

Sheep are currently the animal raised on prairie terrain. Millions of prairie dogs and thousands of bighorn sheep were nourished by vast, uninterrupted horizons of continuous grasslands.

Additionally plentiful were the birds, which included more than 3 billion passenger pigeons, various grouse species, and greater prairie chickens.

Thus, the correct option is A.

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Please Help me with this question!!

Answers

Ide say it’s the first answer that they continue the graph is increasing

There are approximately 259 hectares per square mile. How many deer could a square mile of forest of mature American chestnut trees support for a year if they were the only organism consuming their nuts?

Answers

Answer:

25 deers

Explanation:

According to studies conducted by wildlife experts, a single deer needs roughly 25 acres of land in order to survive comfortably. Therefore we first need to find out how many acres are in a hectare, which based on a quick search online we see that 25 acres equal 10.11 hectares which is what a single deer needs to survive. Now we divide the total amount of hectares by the hectares a single deer needs in order to find out how many deers can survive on this total amount of land.

259 / 10.11 = 25.618

Finally, we can see that the 259 hectares can maintain roughly 25 deers.

What is NOT an example of a primary consumer?
co
A deer that eats mostly grass
b An osprey that eats mostly fish
C
A mouse that eats mostly seeds
d A squirrel that eats mostly acorns

Answers

Answer:

b An osprey that eats mostly fish

Explanation:

or a primary consumer is an animal that feeds on plants; a herbivore.

I need help with this pls

Answers

Answer:

The dependent variable would be B, whether or not the men develop baldness.

please help me!
how can invasive species change an ecosystem?

Answers

Invasive species can change in ecosystem by making there “community “ into theres. Also an invasive species can change an ecosystem by spreading disease, and can be harmful to other species around them.

Some microwaves come equipped with special features that allow you to choose a pre-set time. These buttons are called what? A) intelligent buttons B smart buttons C С mute buttons D awesome buttons​

Answers

Answer:

B smart buttons

Explanation:

Have a good day!

if you feel like it, can you give me brainlyist?

Answer:

B

Explanation:

no give me brainlyist

Please Help Me!!!

Which of the following is TRUE about the flagellum?
The flagellum is a hair-like structure present within the bacterial cell wall.
The flagellum is made up of flagellin proteins.
The flagellum is made up of carbohydrates.
The flagellum is not a mode of locomotion.

Answers

Answer:

So with the explanation the first or second statement might be true.

EXPLANATION:

a slender threadlike structure, especially a microscopic appendage that enables many protozoa, bacteria, spermatozoa, etc.

HOPE THIS HELPS SORRY I COULDNT GIVE YOU MORE INFO!

Answer:

A

Explanation:

i took the test

difference between speed and lvelocity in three point

Answers

Speed, being a scalar quantity, is the rate at which an object covers distance. ... On the other hand, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes. The average velocity is the displacement or position change (a vector quantity) per time ratio.

Explanation:

(1)speed is scalar quantity

(1) velocity is vector quantity

(2)speed can never be negative or zero and it is always positive

(2) velocity can be negative or zero and it can be positive

(3)speed is time taken to travel a specific distance

(3) velocity is time taken to travel minimum distance from 1 point to other point

(4)speed=distance upon time

(4) velocity = displacement (minimum distance between 2 points ) upon time

did u understand if not then comment

What is the best definition for ecosystem

Answers

Answer:  An ecosystem is a biological community of living organisms that are interfacing with the nonliving components of their environment, interacting as a system.

Which of the following procedures demonstrates repetition?

Answers

Marco places a toy car at the top of a ramp. He releases the car and measures how long it takes for the car to reach the bottom of the ramp. Then, he returns the car to the top of the ramp, releases the car again, and makes an additional measurement.

Explain the roles of mRNA and tRNA in protein synthesis

Answers

Answer:

look at Explanation

Explanation:

Molecules of tRNA exist free in the cytoplasm of cells. When protein synthesis is taking place, enzymes link tRNA to amino acids in a highly specific manner. The third form of RNA is messenger RNA (mRNA), which receives the genetic code from DNA and carries it into the cytoplasm where protein synthesis takes place.

48:47
Which of the following factors would have the smallest impact on a population’s size?
a.
the total number of organisms
b.
the available water supply
c.
the variety of organisms
d.
adequate shelter

Answers

I think the answer is c
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