1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
padilas [110]
3 years ago
12

Before fossil fuel use became widespread, which of the following did people use for a. energy?

Biology
2 answers:
Alex777 [14]3 years ago
3 0

Answer: im not 100% but i think its E all

Explanation:

Ratling [72]3 years ago
3 0

Answer:

e

Explanation:

You might be interested in
Science helps people learn about the way the world works. What is the goal of technology?
Valentin [98]
To improve the way people learn.
4 0
3 years ago
Read 2 more answers
Explain what a geographic information system (GIS) is, and describe how a GIS is enabling scientists
yulyashka [42]

Answer:

Explanation:

Geographic Information Systems (GIS) store, analyze and visualize data for geographic positions on Earth’s surface. GIS is a computer-based tool that examines spatial relationships, patterns and trends. By connecting geography with data, GIS better understands data using a geographic context.

5 0
3 years ago
Write short notes on seed germination​
hodyreva [135]

Answer:

Sprouting

Explanation:

process of seed germination, water is absorbed by the embryo, which results in the rehydration and expansion of the cells.

hope this helps

8 0
2 years ago
What happens to a ecosystems food chain if the concentration pollutants move up.
Furkat [3]
<span><span>Producers: Plants are producers because they make usable energy from light.  They turn sunlight, carbon dioxide and water into sugar energy.  Producers are the foundation of the food web, because they provide the base energy needed by all wildlife.</span><span><span>Primary Consumers: </span>Herbivores are primary consumers, because they receive their energy directly from plants. </span><span><span>Secondary Consumers: </span>Carnivores are secondary consumers, because they receive their energy by eating primary consumers.  Secondary consumers are predators.  An omnivore acts as both a primary and secondary consumer, because omnivores eat both animals and plants. </span><span>Decomposer:  Decomposers get energy by breaking down dead plants and animals.  They are extremely important, because decomposers convert dead matter into energy and release nutrients that can be added back to soils and ecosystems.</span></span>


<span>What is a Food Web?
</span>A <span>food web </span>is a diagram displaying how all the producers, decomposers and primary and secondary consumers interact in an ecosystem.  It shows how energy is transferred between species. 

A food web can be very simple - with one producer, consumer and decomposer- or a food web can be extremely complicated.  A food web of an entire woodland ecosystem becomes complex when you include every species from plants to insects and mammals. 


There Is More to a Food Web than Energy

When animals eat their prey, they consume more than just energy.  They also absorb all the chemicals and nutrients inside the prey.  For example, when you eat a banana you get energy from the banana, as well as the added benefits of potassium and vitamin A. 

Sometimes animals ingest pollutants that can become stored in their fat and tissues.  Human-caused pollution has added heavy metals, oil, and <span>industrial and pharmaceutical chemicals </span>to the environment.  Plants, fish and other species absorb these toxins, and as they are eaten by predators, the toxins are then absorbed into the predators’ tissues.  As the chain of predator and prey continues up the food web the toxins become more concentrated and move higher and higher up the food web.  The pollutants can have a disastrous effect on the food web and potentially kill species.


What happens when a Chemical is Added to the Food Web? 
To explain the true impacts of chemicals on the food web, we’re going to use the real world example of mercury poisoning. 

Coal-fired power plants burn coal and release mercury into the atmosphere as a byproduct.  Over time, mercury falls to Earth through rain, snow and natural settling.  Rain carries the mercury to streams and rivers and it eventually settles in lakes and ponds. 

After mercury enters lakes and ponds, bacteria transform mercury into a more easily absorbed toxic substance called methylmercury.  Aquatic plants, bacteria and plankton absorb methylmercury from the surrounding water. 

It’s at this point that mercury becomes added to the food web.  Eventually, the contaminated plants, bacteria and plankton will be eaten by predators, such as fish.  The methylmercury toxins will move into the tissues of the fish and poison a new level of the food web. 


Magnifying Up the Food Web 
Individual plants, plankton and bacteria only have a small amount of methylmercury.  The problem begins at the next level of the food web.  Fish don’t eat just one plankton or plant – they can eat hundreds or thousands of them!  All the mercury in each of the plankton or plants has now been eaten by a fish and absorbed into the fat and tissues.  After eating 100 plankton, the methylmercury in the fish is now 100 times what it was in the plankton! 

It doesn’t stop there.  The higher and higher up the food chain you go, the more food is necessary to maintain energy and activity. 

<span>If a small fish eats 50 mercury contaminated plants.And a large fish eats 100 small fishAnd an eagle eats 100 large fish.</span>

50X100X100 = 500,000  The concentration of mercury in the eagle is 500,000 times larger than it was in the plankton!!

The process that causes the concentration of a substance to increase as it moves up the food web is called bioaccumulation.  Methylmercury is a famous example of bioaccumulation, because mercury poisoning causes neurological disorders, reduced reproduction and even death in raptors and mammals.  People are susceptible to mercury poisoning by eating too much contaminated fish.  

Study the diagram to see how mercury bioaccumulates up this common food web. 

5 0
2 years ago
In 6-8 sentences, explain how stream volume and speed affect the size, shape, and flow of streams and rivers. please help me and
nikdorinn [45]

Explanation:

The speed of water in a stream is affected by the gradient of the geography. The steeper the geography the higher the speed of the water flow and the higher the erosion capacity of the stream. This means the stream will be narrow and deep. There is also less meandering of the stream.

When the gradient is less steep, the stream flow slows down and so does the erosion force it bears especially on the river bed. This therefore result in a higher horizontal erosion than vertical erosion. The steam becomes wide and shallow. The stream is also more likely to meander.

The volume of water in the stream also affects the size, shape, and flow of streams and rivers. A higher volume of water has more erosion power due to the weight of the water column. The stream is, therefore, more likely to be bigger in size than a stream that carries low water volume.  

Learn More:

brainly.com/question/13648696

brainly.com/question/14200651

brainly.com/question/3239165

#LearnWithBrainly

7 0
3 years ago
Other questions:
  • Explain why the villagers believe that a stone is important to ezinma's health.
    9·1 answer
  • What percent of road collisions occur because of mechanical failures?
    11·1 answer
  • What treat food much like heat, refrigeration, or freezing processes to destroy insects, fungi, or bacteria that cause food to s
    12·1 answer
  • Please help!!!! Select the correct location on the image. In which part of the nephron does the filtration of blood occur? glome
    13·1 answer
  • Please answer the question. A, B, C, or D?
    11·2 answers
  • (EASY) Help help MEEE
    11·2 answers
  • How to get fake fever​
    15·2 answers
  • Which of the following is a biotic factor in an ecosystem?
    14·1 answer
  • Match the reproductive structures based on their function and the system to which they belong.
    5·1 answer
  • What type of cytokine stimulates blood cell production?.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!