He is making a plant cell since the cell walls are box shaped, the balloon would be the large vacuole which takes up a lot of space in the cell, the marbles would be the ribosomes.
Answer:
A motor unit is a group of MOTOR NEURON and the MUSCLE FIBERS connected to it.
Explanation:
Neuron is the structural and functional unit of nervous system.
Motor unit consists of a motor neuron and the skeletal muscles innervated by the terminals of the neuron.
Several associated motor units called motor pool coordinates together the contractions of a single muscle.
That is, the activation of a motor unit leads to the contraction of all the muscle fibers attached to it.
Answer:
Option (A), (C) and (D).
Explanation:
Introns are the non coding nucleotide sequence of the gene. They may present within the gene or may lie outside the exons. Introns are responsible for the gene evolution.
Introns can also responsible for encoding the proteins subunit. Introns needs to be removed from the exons by the process known as splicing. Different splicing are alternate splice, group I and II intron. Different multiple introns can be present in the gene.
Thus, the correct option is (A), (C) and (D).
C, mitochondria. Mitochondria are the powerhouses of the cell and produce energy for the cell.
