The answer to this question is nitrates. Nitrate is a
compound that is composed of nitrogen and oxygen. Nitrates are used as a
preservatives in food, can be used as fertilizer, an ingredient to make gunpowder,
and also an ingredient in making explosives or bomb.
Answer: ionotropic; metabotropic
Explanation:
A receptor can directly open the channel and exerts an ionotropic effect. The ionotropic effect takes place by the help of ionotropic receptors. These receptors are membrane bound receptor proteins which responds by the bonding of the ligand.
Due to ligand binding the channel opens and allows the movement of ions into the cells which helps in either increasing or decreasing the action potential.
The receptors can also bind to the ligand and produce metabotropic effect which means by the second messenger.
Endocrine and circulatory (C) Endocrine system consists of glands and the hormones they secrete whist the circulatory system is the blood or as I like to call the “transport system” of the body.
Answer:
D. heterotrophic by ingestion, pseudopods
Explanation:
Protists are generally classified as all eukaryotic organisms that are not plants, animals or fungi. Example is amoeba, paramecium etc.They may be unicellular or multi cellular in nature.Most exist in colonies.
Their mode of nutrition can be photosynthetic or hetrotrophic. Hetrotrophic protists can be divided into phagotrophs and osmotrops/saprotrophs. The phagotrophs makes use of the cell body to engulf the food materials as in amoeba ,carry out extracellular digestion before swallowing it.
Osmotrops absorbed dissolved food from surrounding liquid environments directly. (Some photosynthetic protists can also be heterotrophic.
Amoeboid movement is the mode of locomotion of protists and some other eukaryotes. It involved the protrusion of cytoplasm, which exert pressure on the cell membrane to form pseudopodia and the posterioly evolved <u>Uropods. </u>
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<u>Sol-gel theory has been proposed to expalin this movements, The ectopalsm of amoeba is gelly-like , while the endiplams is less viscpus and said to be sol. The interchange of the cytoplasmic fluis between the endo-and ecto plasm gives the SOL-GEL propulsion of the protopalms for the amoebic moveemnts .</u>
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<u>The false feet(psuedopodium) drags the amoeba along in the direction of the flow of the cytoplasm.</u>
Therefore option D is the right option
Answer:
The correct answer is option 3. a nucleus.
Explanation:
The first genetic material present in the early organisms were RNA which was present in the microscopic organisms back then 3.5 billion years ago which means it is normal to have RNA in such microfossils chemical analysis.
Since, the nucleus was not present in early life forms of prokaryotes like bacteria. so, it is unusual to find nucleus in the fossils of stromatolite rocks.
Thus, option III is the correct answer.
