To answer your question: the nucleus has a membrane.
This kind of modeling is known as (D) simulation. A computer program is used to simulate an environment, in this case, the zoo. Instead of having to do an actual experiment which harms real animals, a simulation is done to cut costs and avoid using live samples.
Focus because it means <span> the point beneath Earth's surface where rock breaks under stress and can cause an earthquake to happen.</span>
Your heart rate before exercising would probably be the at rest rate of say about 50-60 beats per minute whereas immediately after exercise it could easily be say 115-130 and depending on age there is an optimum heart rate for each age range which decreases somewhat with age. Timing for a full minute your heart rate is best as it will give the actual count whereas if you just do it for 10 seconds and then multply by 6 it would assume it will be consistent whereas it could decrease during the minute so the actual measured count for a full minute is more accurate.
