Answer:
Nervous stimulus action for muscle contraction
Explanation:
Nerve stimulation is sent to the sarcolemma, which are motor nerves at the neuromuscular junction (junction between the terminal part of a motor axon with a motor plate), after which nerve endings implant in the sarcolemma and form plaque on the surface of muscle fibers, which in turn transmit stimulus to the musculature.
Then, an electrical current (from the stimuli) is generated, it propagates through the muscle cell membrane, reaches the cytoplasm and triggers the muscle contraction mechanism.
Answer:
Neurons have stable, relatively unchanging internal environments.
Explanation:
Neurons or nerve cells is the structural and functional unit of the nervous system. Neurons consists of the dendrites, axon, cell body and different cell organelles.
The neurons have mitochondria that meets the high ATP requirement and and consume more oxygen. The network of rough endoplasmic reticulum and ribosomes produce large number of proteins in neuron. The internal environment is never stable and gets changed as the nerve impulse transmission occur through the neuron. The membrane potential of the neuron gets changed and changes its internal environment.
Thus, the correct answer is option (B).
Answer:
15 chromosomes
Explanation:
The endosperm is formed through double fertilization where one male gamete nucleus with polar nuclei to form a triploid nucleus called the primary endosperm. The endosperm therefore will contain 15 chromosomes since the polar nuclei is diploid and the male gamete is haploid forming a triploid nucleus.
Vascular tissue is located inside the pericycle of a root, which I believe would be considered the inner layer.
