Question

Question 2 1 pts Graded potentials are different than action potentials since graded potentials: can beelther depolarizing or hyperpolarizing while action potentials always hyperpolarizing O can be generated at the exposed areas of an axon while action potentials are only generated at the some of the Duron have the same strength no matter the intensity of the stimulus while action potentials vary in their strength (magnitude) with the intensity of the stimulus. Ocause the breakdown of neurotransmitters from a neuron while action potentials cause the exocytosis of neurotransmitters from a neuron. can undergo temporal or spatial summation to depolarize or hyperpolarize a cell while action potentials do not undergo summation D Question 3 1 pts The functional unit of a muscle is called a muscle fiber O muscle cell O sarcoplasmic reticulum myofibril

Answer 1

• Graded potentials are different from action potential because they can undergo spatial (across space) and temporal (across time) summation while action potentials do not and that is due to the presence of refractory periods. The first statement is partially true but not completely because action potentials always lead to depolarization, not hyperpolarization. Moreover, action potentials are generated at the axon, not at the soma of the neuron. Hence, the correct answer is the last option.
• The functional unit of a muscle is the sarcomere. Myofibril is made up of repeating structures of sarcomere which constitute actin and myosin filaments, fundamentally involved in muscle contraction. Many myofibrils make up a bundle of muscle fibre which build the skeletal muscle. Sarcoplasmic reticulum surrounds the myofibril is responsible for storing calcium ions.