The correct answer to this question is this one: they lacked oxygen. The earliest organisms were completely heterotrophic in nature because of the reason that they lacked oxygen. <span>A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. </span>
Well, the carbon cycle provides an example of matter cycling and energy flow in ecosystems. Photosynthesis, digestion of plant matter, respiration, and decomposition are important components of the carbon cycle, in which carbon is exchanged between the biosphere, atmosphere, oceans, and geosphere through chemical, physical, geological, and biological processes.
If the presence or absence of a factor limits the growth of the ecosystems elements, it is called a limiting factor . There are several abiotic factors that limit ecosystem growth, including temperature, precipitation, sunlight, soil configuration, and soil nutrients
The correct answer is A) Chlorophyll absorbs sunlight energy for photosynthesis.
Answer:
RNA
Explanation:
CRISPR system was discovered by a Japanese scientist. Naturally <u>bacteria and many other prokaryotes</u> have <u>CRISPR system in their genome</u> which they use as a<u> self defense against a pathogen</u> which is invading them. It consists of<u> inter spaced, short palindromic nucleotide repeats </u>which <u>encode a guide RNA (gRNA)</u>. This guide RNA (gRNA) recognizes the<u> target sequence</u> on the pathogen. The <u>gRNA is followed by Cas9 enzyme</u> which along with the gRNA plays a very important <u>role in breaking genome</u> of the pathogen. Once the target gene is cut down the rest of the DNA can be rejoined by<u> non homologous end joining. </u>
But nowadays, scientists are using this system for <u>genome editing</u> and <u>incorporating desired gene</u> between the two ends which are cut down by <u>CRISPR Cas9 system.</u>
