What term do historians use to describe the personal preferences that people have that affect their interpretation of events?

A certain lake has a volume of about 480 m³. If the total population of freshwater shrimp in the lake is 600 million, what is th

emmainna [20.7K]

Answer:

1,250,000 shrimps per m³

Explanation:

Population density refers to how dense an area is per unit area/volume, and it is calculated by dividing the number of individuals in that area (population) by the area/volume of that area. That is;

Population density = population (N)/volume

According to this question, a certain lake has a volume of about 480 m³ that harbors a 600 million of freshwater shrimp. This means that;

Population density of the lake = population of shrimps ÷ volume of lake

Population density = 600,000,000 ÷ 480

Population density = 1,250,000 shrimps per m³

5 0

3 years ago

Look at the graph below.

Masja [62]

You should reask this question and put a picture so that we can understand it better :)

5 0

3 years ago

1. How many food chains make up the food web?

viva [34]

Answer:

A food web can be formed by more than one food chain, since the webs includes all possible interactions that can occur between individuals of different trophic levels.

Explanation:

Based on the scheme shown in the image

<h3>1. How many food chains make up the food web? </h3>

This food network is made up of three food chains

<em>Plant → Bird → Snake</em>
<em>Plant → Insect → Bird → Snake</em>
<em>Plant → insect → Frog → Snake</em>

Food webs often include several food chains, since they are due to the interaction between organisms at different trophic levels, which actually happens within an ecosystem.

<h3> 2. Which organism is an herbivore? </h3>

In this case, both the insect and the bird are herbivorous organisms, since they feed of the producer, which is the plant.

<h3> 3. Which organism is an autotroph? </h3>

The only autotrophic organism is the plant, since it is capable of manufacturing its nutrients from sunlight and inorganic matter.

<h3> 4. Which organism is a third-order heterotroph? To what trophic level does that organism belong? </h3>

The third order heterotroph is the snake, since it feeds on other animals. The snake is a carnivore and can be a secondary or more commonly tertiary consumer, so it can be placed in the 3rd or 4th trophic level.

<h3> 5. Which organism is an omnivore? </h3>

According to the scheme proposed, the bird is omnivorous, since it feeds on both plants and insects.

<h3> 6. Which organisms belong to more than one food chain? </h3>

In this case, the plant, the insect, the bird and the snake are part of more than one food chain.

<u><em>Plant → Bird → Snake</em></u>
<u><em>Plant → Insect → Bird → Snake</em></u>
<u><em>Plant → insect</em></u><em> → Frog → </em><u><em>Snake</em></u>

<h3> 7. Which organism belongs to more than one trophic level? </h3>

The bird can be located in both the second and third trophic level, being a primary consumer —when it feeds on plants— or secondary, when it feeds on insects.

<h3> 8. What are decomposers? From which trophic levels are the organisms that decomposers feed on? </h3>

Decomposers are generally bacteria and fungi, organisms capable of degrading organic matter, thus enriching the soil. Decomposers can feed on any trophic level.

<h3> 9. What does a pyramid of energy show about the amount of energy available at different trophic levels of a food chain? </h3>

As the ascent of the pyramid occurs —or at the upper trophic level— the amount of energy available decreases. This is because from one trophic level to another only 10% of the energy can be used. If a plant has 5000 Kcal available, the herbivore that consumes it can only use 500 Kcal.

<h3> 10. Why do different trophic levels have different amounts of energy?</h3>

The main <u>reason for the difference in energy in each trophic level is that energy is lost in each one of them</u>, which the organisms use in their metabolism. A consequence of the metabolism is the loss of energy as heat, which is acquired by the environment.

8 0

3 years ago

vanessa had been advised not to use pesticides that will harm the bees in the orchards.suggest one reason why it is important fo

jasenka [17]

Answer:

Pesticides vary in their effects on bees. Contact pesticides are usually sprayed on plants and can kill bees when they crawl over sprayed surfaces of plants or other areas around it. ... When a bee comes in contact with pesticides while foraging, the bee may die immediately without returning to the hive.

8 0

3 years ago

Jonas Salk was awarded the Nobel Prize for discovering a way to vaccinate against

Bogdan [553]

Answer:

Jonas Salk was awarded the Nobel Prize for discovering a way to vaccinate against polio in the United States in the 1950's. This allowed millions of school-age children to avoid crippling disease, and to swim during summer again, as polio was often spread in public swimming areas before.

The statement that best describes how the polio vaccine works is:

It triggers the immune system to produce antobodies to fight the disease-causing agent.

Explanation:

There are two main reasons for this answer. The first one is that every vaccine is aimed to introduce a controlled amount of antigenes to be accepted by the organism. These antigens are made after some studies were conducted in a lab and were obtained from substances that the human body can accept to train the immune system to develop an effective defense for the virus or bacteria on the matter. In our case, the polio vaccine works the same way and allowed to save many lives.

3 0

3 years ago