Answer:
1 = A
2 = B
3 = B
Explanation:
1) Black holes occur when really big stars collapse on themselves. And, in order to get big, the star has to be an old one.
2) A black hole is something huge that swallows up everything, while a protostar is just the very beginning of a star.
3) Scientist can't truly know for sure, but they can infer about them due to the effects of the surrounding areas.
Answer:
Antibiotic resistance occurs when bacteria do some variation in their genome that allows bacteria to eliminate the effect of antibacterial drugs. Irregular or excessive antibiotics use is the main cause of generating antibiotic resistance bacteria.
So antibiotics should be taken only on the prescription of doctors and a complete course of antibiotics should be done to eliminate all the bacteria so that no bacteria is left to generate antibiotic-resistant bacteria.
Antibiotics should be avoided in viral infection as antibiotic does not kill viruses as it is only beneficial in bacterial infection.
Photosythesis is carried on in the Chloroplasts, in this diagram i believe the Chloroplasts are (D).
Motor unit refers to the functional element of muscle contraction during an exertion. There are two basic types of motor unit: large and small motor units. During low to moderate level exercise, small motor units are activated. Small motor units are recruited during sustained activity; is made up of high proportion of type 1 muscle fibers, which are resistant to fatigue
The theory that a drug attaches itself to specialized cells in the body because of its size, shape, electrical charge, and chemical properties is called receptor site theory.
c.
