Answer:
It has gotten worse.
Explanation:
In the past 30 years, air quality in the United States has declined almost exponentially. Pollution is the main reason for the declination of air quality in the United States, but there are different kinds of pollution, including light pollution, noise pollution, air pollution, water pollution, etc. Air pollution can be caused by primary or secondary pollutants. Primary pollutants include carbon, nitrogen, and sulfur oxides as well as just general particles in the air. Secondary pollutants are formed when pollutants are exposed to sunlight via chemical reactions.
The plasma membrane of the sea urchin egg has receptor molecules that are specific for binding acrosomal proteins .
<h3>What is plasma membrane ?</h3>
Plasma membrane is the outermost covering of the body which selectively permits the entry and exit of different type of materials .
Thus ,it is also called as selectively permeable membrane.it also separates the inner and outer environment of the cell .
It also helps in the diffusion process .
<h3>What are sea urchins ?</h3>
Sea urchins belongs to the animalia kingdom , Echinodermata Phylum, and Echinoidea class . they are small marine animals .Sea urchins are spiny , globular .
Learn more about sea urchins here :
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Answer:
Genetic engineering has multiple applications in different fields. Genetic engineering is the process by which alterations are made at the genetic level so that the final product is superior in quality and yield.
Explanation:
Following are few of it's applications:
<u>Medical field</u>- Genetic engineering is been used to produce insulin artificially, human growth hormones, anti hemophiliac factors, vaccines and other drugs.
<u>Agricultural industry</u>- It has been used to synthesize improvised crops which give better yield and are pest resistant. E.g Flavr savr, a species of tomato which is more juicy and larger in size than regular tomatoes.
<u>Environment</u>- With the introduction of herbicide resistant corn, farmers reduced the use of tractors which in turn reduced the amount of greenhouse gases. Also, by imparting disease resistance to plants, a lot of plants are prevented from dying. In addition, the biodiversity of an area can be maintained.
Answer:
A compass needle is affected by Earth's magnetic field.
A magnetic field is strongest at the poles.
Explanation: