According to a source the answer is <span><u>Cyanobacteria were the first organisms to produce oxygen in water, which then escaped into the atmosphere.</u>
These cyanobacteria species were the first ones to "produce" oxygen as a by-product of the photosynthetic mechanisms which enables organisms to make their own food. </span>
Answer:
Flatworms and cnidarians
Explanation:
In simple organisms, such as cnidarians and flatworms, every cell in the body is close to the external environment. Their cells are kept moist so that gases diffuse quickly via direct diffusion. Flatworms are small, literally flat worms, which 'breathe' through diffusion across the outer membrane
-They are multicellular organisms which do not possess chlorophyll.
-They are eukaryotic organisms.
-Cell wall is absent.
-Mode of nutrition is heterotrophic i.e. they depend on other organisms for food.
Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other.
Answer:
Considering the organization of the body the level of organization in which proteins like collagen are found is the molecular level, and this level of organization allows the construction of the structure and functions of the whole body.
Explanation:
Collagen is a protein molecule that belongs to the molecular organization level, like all biomolecules.
Proteins have multiple functions in the body:
- <em>They participate in the construction or structure of the body.
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- <em>They form specialized proteins, the enzymes, to facilitate organic chemical reactions.
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- <em>They are part of the structure of cell membranes, allowing cellular recognition and transmembrane transport.
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In this way <u>the protein molecules, belonging to the molecular level, contribute to the organization of the whole body</u>.
