Question

1. Which group comprises all lithotrophs?

A. algae

B. autotrophs

C. microbes

D. plants

Answer 1

c.Microbes

lithotrophs - Lithotrophs are a diverse group of organisms that use inorganic substrates (usually of mineral origin) to obtain reduced biosynthesis equivalents (e.g. carbon dioxide fixation) or energy conservation (e.g. ATP production) through aerobic or anaerobic breathing. The known chemolithotrophs are micro-organisms only;Known chemolithotrophs are micro-organisms only; no known macrofauna possesses the ability to use inorganic compounds as sources of energy.An example of this is chemolithotrophic bacteria in giant tube worms or plastids, which are organelles within plant cells that may have developed from species like photolithotrophic cyanobacteria. Lithotrophs belong to either the Bacteria domain, or the Archaea domain.The term "lithotroph" was created from the Greek terms "lithos" (rock) and "troph" (consumer) which means "rock eaters." Many lithoautotrophs are extremely sophisticated, but this is not universal.

Autotrophy is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances found in its environment, generally using light energy (photosynthesis) or inorganic chemical reactions (chemosynthesis)

Algae-Most microalgae grow through photosynthesis-by converting sunlight, CO2 and a few nutrients, including nitrogen and phosphorus, into material known as biomass. Other algae may grow in the dark using sugar or starch (known as "heterotrophic" growth), or even combine both growth modes (known as "mixotrophic" growth).

Plants-An autotroph is an organism that uses light, water, carbon dioxide, or other chemicals, to produce its own food. Since autotrophs produce their own food they are sometimes referred to as producers. Plants are the most common autotrophic species but many different types of autotrophic organisms exist.