Answer:
B. Electron Cloud
Explanation:
It would not be A because, electrons orbit the nucleus so they cannot be physically IN it.
It cannot be C either because, we are talking about an atom not a cell. Mitochondria is only present in cells.
Answer:
3: A device that uses radioactive fluid to determine the active areas of the brain
Explanation:
A positron emission tomography (PET) scan is an imaging test that helps reveal how your tissues and organs are functioning. A PET scan uses a radioactive drug (tracer) to show this activity. This scan can sometimes detect disease before it shows up on other imaging tests.
Depending on the type of exam, the radiotracer is injected, swallowed or inhaled as a gas. It eventually accumulates in the area of the body under examination. A special camera or imaging device detects radioactive emissions from the radiotracer. The camera or device produces pictures and provides molecular information.
Plants’ nonspecific immune responses includes cell-surface receptors (pattern recognition proteins) which allow them to identify certain patterns characteristic for pathogens. Activated receptors trigger the production of chemical signals that may initiate both local and systemic defense responses. Sometimes when a plant is affected by infection, it triggers rapid localized programmed cell death to stop the infection further. When it comes to defense form the herbivores, plants have physical barriers (plant cell walls and their extensions), some antibiotic compounds (phytoalexins), and even enzymes that can defend them.