1-A teacher started his class at 7:00 and 15 min and finished at 8:50 a. m. How many minutes did class last? 2-Doing physical exercises for 50 min per day for 20 days, how many hours will be spent per month to do these exercises?

3-In a school each class lasts 50 minutes and each class has 5 lessons per day. Knowing that there is a 30-minute break, calculate how many hours students spend per day at this school.

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What two fields of study provide the core information that is used to classify organisms?

Which particle controls what element an atom is?

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).