Darwin went to the continents of Africa and South America, wherein both of them have a tropical grassland/Savanna biome. The grasslands in these continents gave him a chance to notice that species do vary globally. He observed the similarities between the different large, flightless birds species–rheas, ostriches, and emu.
The stem cells possessing the characteristic of self-renewal and limited differentiation are present in the amniotic fluid.
The cells present in the amniotic fluid are capable of forming a wide array of different cells. However, they are not pleuripotent, but when grown in the right environment they can form brain, liver, fat, blood vessels, bone and muscle cells.
Hence, the answer is 'Option C - amniotic fluid'.
Bacteria have 1 cell, they reproduce asexually and create other 1 cell bacterium.
Answer:
Explanation:
It certainly isn't the last one. A theory is close to a guess. It fits all the known facts, but there is usually something missing. If someone figures out what is missing, usually by experiment, then the theory become a fact.
The rest of them (1 2 an 3) can all be true. 3 is the least viable. You have to be able to come up with a counter example to reject a theory.
I'm not sure about 2. New phenomena can still be part of current theories. Reluctantly, I wouldn't choose 2 because
1 is the best answer of a very poor lot. Do not be surprised if you use it, that it turns out to be wrong.