Answer:
These microbes conduct photosynthesis: using sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen. In fact, all the plants on Earth incorporate symbiotic cyanobacteria. For some untold eons prior to the evolution of these cyanobacteria, during the Archean eon, more primitive microbes lived the real old-fashioned way: anaerobically. These ancient organisms—and their "extremophile" descendants today—thrived in the absence of oxygen, relying on sulfate for their energy needs. But roughly 2.45 billion years ago, the isotopic ratio of sulfur transformed, indicating that for the first time oxygen was becoming a significant component of Earth's atmosphere,
B I think is the correct answer
The B cells are not considered as first line defense structures of the immune’s system
Answer: Option C
<u>Explanation:</u>
Our body is protected internally by nature by many layers of defense. Any microbe or a foreign material that disturbs the body is defended by these barriers.
The first layer of defense required physical and chemical barrier such as the skin, mucous membrane, tears, saliva etc . The second line defense system involves the cells and the tissues that protect the body.
Answer:cacti
Explanation:
In an ecosystem,the ultimate source of energy is the sun. Plants take up this energy from the sun to produce food. Animals eats up plants and when they die ,they decompose. This continuing process leads to the transfer of energy from one trophic level to another in the ecosystem.
Plants ,algae and some bacteria are the primary producers in the ecosystem.they are able to make their own food and support the entire living system. They extract inorganic nutrients and energy from the environment, in order to make their food. Animals(herbivores) eats up the plants and other animals(carnivores) eat up such animals. This situation sets up a chain of flow of energy from the producer to the consumer and back to the environment.
50% it said i need more words hope this helps have a nice day.
