Answer: False
Explanation:
Protozoans are not the organism that fix nitrogen for the plants. The organism that fix nitrogen to convert it into a form which can be used by plants are known as diazotrophs.
These are bacteria and archae that fix nitrogen gas found in the atmosphere into more usable form such as ammonia.
These organism can grow without any external source of fixed nitrogen. Example: Rhizobia and azospirillium.
Answer:
B. Australia is isolated
Explanation:
They originated in South America and spread throughout the world, but due to competition on other continents, the other marsupials died out, while the ones on Australia lived.
Explanation:
(1) The conglomerate contains some nonsedimentary rock fragments. (2) The conglomerate was formed from material that was buried deep underground. (3) The conglomerate's pebbles are all weathering at the same rate.
Given that,
The speed of a wave, v = 200 m/s
Wavelength, 
We need to find the frequency of this wave. The relation between wavelength, frequency and the speed is given by :
So, the frequency of this wave is 100 Hz.
Americium, the atomic number is 93
