Species change over time. -The mechanism that produces the change is natural selection: the differential survival and reproduction of individuals based on variation in their traits. Natural selection acts on individuals but individuals do not evolve; their descendants do.
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Answer:
Nitrogen cycle works through various stages like, nitrogen fixation, nitrification, assimilation, ammonification, denitrification etc. It is a building block for protein and DNA
Explanation:
Nitrogen is an element abundantly found in the atmosphere, also its building block for proteins as well as nucleic acid i.e. DNA formation. In nitrogen cycle , the nitrogen is being prepared from inert nitrogen. The nitrogen cycle has several processes like nitrogen fixation, in this the inert nitrogen is being converted to organic nitrogen with the help of certain micro-organism.
Nitrification, plants cannot absorb directly nitrogen so bacteria help the plants to convert the nitrogen into ammonia form in this stage. Assimilation, another stage in which plants starts absorbing various forms of nitrogen from the soil.i.e. nitrate, nitrite and ammonium. Ammonification, here plants and animals have nitrogen in there body after death various microbes help in decomposition in this stage. Denitrification, in this stage the return back of nitrogen takes place.
Answer:
Explanation:
Bacterial count in stock- 1.85x10^6 cfu/ml
Dilution methods
Take 100 uL or (0.1ml) from stock and add to 900ul (0.9ml) saline and mixed it- this makes 10^1dilution.
Now take 100ul from 10^1 dilution and add to next 900ul saline this is 10^2 dilution, similarly do upto 10^5 dilution.
Then take 100ul from 10^ 4 and 10^5 dilution seperately and plate on LB agar plate seperetely and count the colonies.
Cfu/ml formula= (No.of colonies x dilution factor)/0.1 ml
So suppose, 18 colonies formed on 10^4 dilution then total no. Of cells in stock will be 18x10^4/ 0.1= 18x10^5 cfu/ml.
If we dilute 10^4 or 10^5 that's leads to colony count of 18-19 colonies on 10^4 dilution while 2 colonies should come on plate of 10^5 dilution.
Since ponds are typically shallower than lakes, this allows more sunlight to reach pond plants than lake plants. By getting my sunlight, these pond plants can photosynthesize more efficiently.
