Answer: we can make observations directly by seeing, feeling, hearing, and smelling, but we can also extend and refine our basic senses with tools: thermometers, microscopes, telescopes, radar, radiation sensors, X-ray crystallography, mass spectroscopy, etc. And these tools do a better job of observing than we can!
Olivine, pyroxene, amphibole, mica, and quartz
Answer:
Cancer disease occurs when the abnormalities occurs during cell division of stem cells. Stem cells are those cells which are produced in the body and used by the body when the cells are older or get damaged. When the division of these stem cells are uncontrollable, cancer occurs which spread to the surrounding cells. When a large group of cancer cells grow in size, it turns into tumor.
The correct answer is d. spinal cord.
Spinal cord is a bundle of neurons which starts from the brain and runs down the entire length of the back of the body. The spinal cord acts as a main means to transmit the messages between the brain and the body.
Sensory or efferent neurons carry the information from the perimeter of the body and pass to the central nervous system whereas the motor or efferent neurons act as a communication channel and carry the information from the nervous system to various glands and muscles.
The appropriate answer is D. Alfalfa. Alfalfa is a legume and these plants play a key role in the nitrogen cycle. These plants house nitrogen fixing bacteria on their roots. The bacteria are housed in tiny round structures of leguminous plant roots. Once the nitrogen is fixed in the soil it can now be used by other plants to make food. These plants include beans peas and peanuts. <span />
