Answer:
1.A tissue is a collection of similar cells that work together to perform a specific job.
An organ is a collection of different tissues that work together to perform a specific job. The function of a part of an organism is what it actually does (it's job)
2.The structure of the alveoli as a web of blood vessels surrounding an air sac allows blood cells take in oxygen and bring it into the lungs (organ)
Answer: Louis Pasteur
Louis Pasteur in 1860s, proposed germ theory. The theory was based upon the fact that diseases are caused by the microorganisms.He was officially the first to publish his work.
Answer:
There are many invasive animal sand plants which are harmful for native flora and fauna. Some of the invasive or alien species are as following:
<u>1. The Nile Perch:</u><em> </em>Nile Perch is a type of fish which is native to African lake and river systems but if it is introduced in other countries lake it can be dangerous to other fishes in that lake. It was earlier introduced to Lake Victoria but after sometime it was evaluated that native fishes got extinct and the Nile Perch become very huge in size.
<u>2. The cotton whitefly: </u> Cotton whitefly are native to India but now can be found on most of the continents and have very bad impact on the fauna or agricultural plants. They have capability of transmitting upto 100 different plant viruses. find them thriving
<u>3. The desert locust:</u> The desert locust is a species of locust which can fly and are one of the most disastrous migratory pests in the world. They feed over green green vegetation, including pasture, crops and fodder. They have very bad impact on native flora as they are migratory pests. They are found in Africa and migrated to nearby countries such as India and damages the native flora.
<u>4. European starlings:</u> European starlings are the bird species which fight with native species for food and shelter. They are found in Alaska and Mexico and proved invasive in U.S. as the number of native birds decreased with their introduction.
<span>A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.</span>