Answer:
to help and determine the exact age of the rocks
Explanation:
The study of rocks strata is known as stratigraphy. It is useful and helps the scientist and the researcher to study the earth's crust and its past.
Scientist could age the rock using two methods. They are :
Relative ages
Absolute ages
Early scientist could determine the exact age of the rock of the earth's crust. They use to find the relative ages of the layers of the rocks and then determine how one rock layer is older or younger than the other. But with advancement and development of carbon dating, scientist could tell the exact age of the rocks found on the earth's crust.
The Scientists uses the relative as well as the absolute dating technique to date the rock layers. They organize the rock layers based on their age and scale from the oldest to the youngest on a geologic time scale. So an exact date of the rocks can be determine by using the two methods of relative age and the absolute age.
Answer:
All of the living organisms have the ability to adapt.
Explanation:
Answer:
The correct answer is - option B. ducks and swine.
Explanation:
Influenza virus is capable of the genetic reassortment. This reassortment involves the reassortment of genetic parts in between two influenza strain. This takes place due to the ability of influenza virus to alter or modify the structure of Hemagglutinin (HA) and neuraminidase.
Some other characters also helps them to develop different strains for different host such as mutation, antigenic drift and many other conditions. Influenza virus subtype A are belongs to the avian host so they affect the birds such as duck, swan, gesse. Other than avian variants there is another strain that affect pigs known as swan variants. These strains are virulent if reassorted with human strains.
Thus, the correct answer is - option B.
Answer:
<h2>They are classified on the basis of their cell wall composition and as well as by the reaction to the Gram stain test.
</h2>
Explanation:
Most bacteria are classified into two main categories
i) Gram positive bacteria and ,
ii) Gram negative bacteria.
They are classified on the basis of their cell wall composition and as well as by the reaction to the Gram stain test.
Gram positive bacteria's characteristics
ii) they have cell walls composed mostly of peptidoglycan.
i) stain purple after Gram staining.
Gram negative bacteria's characteristics.
i) they have cell wall only a thin layer of peptidoglycan and an outer membrane with a lipopolysaccharide component.
ii) stain red or pink after Gram staining.
Answer:
A
Explanation:
This is because they have been displaced from short term memory