In the food chain, a producer absorbs energy from the sun and then uses photosynthesis to turn the sunlight into energy. Then, one of the consumers in the food chain will eat the producer and obtain the producers energy.
Answer:
Oxygen became available from cyanobacteria
Explanation:
Answer:
The correct answer is biological.
Explanation:
When any pathogen invades the body, it has to pass several lines of defence. The first barrier is the skin and mucous membrane which is a physical and chemical barrier. The second line of defence is the non-specific response by macrophages, neutrophils and interferon. After crossing these two barriers the third line of defence comes into action in which, the B- cells and T-cells act specifically on the pathogen and destroy it.
