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3 years ago

Daphnia are freshwater organisms sometimes referred to as “water fleas.” Design an experiment that

2 answers:

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Hypothesis: Daphnias can increase in population at a room
temperature, rather than a colder or warmer temperature.

Control group will be at a room temperature water. The experimental will be tested in cold and warmer waters.

Independent variable: change of water temperature.

The data will be the amount of growth in which the water fleas population increases or decreases, a bar graph would work.

Aleonysh [2.5K]3 years ago

3 0

Answer:

Experiment to test the effect of temperature on the size of a daphnia population:

1. The hypothesis to be tested is: "Cooler temperature will reduce the size of the population due to a decrease in the reproduction rate while the hotter temperature will increase the size of the population due to an increase in the reproduction rate.

2. In all groups, daphnia will be counted weekly at the same time. The amount of water and nutrients supplies will be the same between groups. The only thing that will change is the temperature. For example:

Control group will be at 20 Celcius degrees, the cooler group will be at ten Celcius degrees, and the hotter group will be at 30 Celcius degrees.

3. The independent variable is the temperature.

4. The dependent variable (data that will be collected) is the size of the population.

Explanation:

Daphnias are microscopic crustaceans, which are called water fleas because of their saltatory behavior like fleas. Their life span and reproduction can be affected by different factors, including the abundance of predators, food, and temperature. They alternate their reproduction strategy during their life; they can reproduce asexually and sexually. Lower temperatures (cooler) decrease their metabolic and reproduction rate while higher temperature (hotter) increase their metabolic and reproduction rate. Because they can reproduce more times during their life span and the reproduction rate is higher in higher temperatures, I expect that temperature will affect the size of the population of Daphnia.

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People with panic disorder show dysregulation of norepinephrine systems in an area of the brainstem called the:_________.a. basa

antiseptic1488 [7]

Answer:

B. locus ceruleus.

Explanation:

A nucleus present in the pons of brainstem responsible or involved in physiological responses to panic and stress is known as locus ceruleus.

Basically, locus ceruleus is responsible for the primary production of norepinephrine in the brain. The nucleus transfers the norepinephrine to whole cerebral cortex along with various other structures like amygdala, cerebellum, hippocampus, and spinal cord.

So, when there is a panic disorder due to norepinephrine dysregulation at the brainstem area which will be definitely locus ceruleus.

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2 years ago

Whales, humans, lizards, and birds each have forelimbs that are adapted for different functions, including swimming, using tools

Elis [28]

Answer:

A. These homologous structures indicate that these four organisms all share a common ancestor.

Explanation:

Homologous structures mean the organs will have similar structure, but not necessarily function (human arm vs whale's flipper). While analogous structures are similar in function but not structure (wings of an airplane vs wings of a bird). Since the question states that they are similar in skeletal structure, we know they must be homologous structures, thereby eliminating B and C. D is not a choice because the question does not provide anything about the order of evolution. Therefore the answer is A. These homologous structures indicate that these four organisms all share a common ancestor.

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2 years ago

I don’t know if you can see the answers but I really need help on it

aleksklad [387]

I think it is A because they can just destroy it but D is finding something natural to kill it off but it is GM so it wouldn't help so A

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3 years ago

WILL MARK BRAINLIEST match the word to the correct description

pickupchik [31]

Answer:

1. High pressure: Happens when air cools and it becomes denser...

2. Low pressure: Happens when warm air rises...

3. Cold front: Cold air mass is replacing a warm air mass...

4. Warm front: Warm air mass is replacing a cold air mass...

5. Sun: Is necessary for evaporation to take place.

6. Nimbus clouds: Dark clouds that have rain or snow falling.

7. Cumulus clouds: Fluffy, dense clouds most composed of droplets.

8. Atmosphere: The layer of gases that surround the Earth.

9. Nitrogen: Makes up 78% of Earth's atmosphere.

10. Troposphere: Lowest layer of Earth's atmosphere. Where we live. Where we find most weather.

-Hope this helps.

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3 years ago

Read 2 more answers

What is used to break the bonds of nodules??

olga_2 [115]

<span> </span><span>Bean roots will have no nodules if there are no compatible Rhizobium bacteria in the soil. The nodule is a symbiotic relationship between the plant and the bacteria. Nitrogen fixing root nodules are pinkish in color. Green root nodules indicate actively reproducing bacteria that are not fixing nitrogen. The number of nodules depends on the amount of innoculant (Rhizobium) available in the soil. Look at the photos and make an estimate like x nodules per y linear inches of root. Hope this helps.

The edible part of the radish root functions as a food storage organ. The string parts of the radish root function as normal roots absorbing water and dissolved nutrients. Bean roots have no modifications for food storage. Radish roots don't have nodules. The radish root is a "tap root". The bean root is a "fiberous root"

Beans don't grown faster than radishes because of the root nodules. Bean seeds are large. Radish seeds are small. The energy stored in the bean cotyledons helps the seedling get a fast start. The radish gets a slower start from less stored energy.</span>

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3 years ago