Atom, molecule, cell, tissue, organ, and organ system
Answer: Animal cells and plant cells share the common components of a nucleus, cytoplasm, mitochondria and a cell membrane.
Answer:
A- Acetylcholine is released by axon terminals of the motor neuron.
Explanation:
The general mechanism of muscle contraction can be explained as follows:
a) The action potential which is generated, travels along the motor nerve to its ends on muscle fiber (or motor end plate) at the neuro-muscular junction.
b) The nerve endings then secrete small amounts of neurotransmitter called acetylcholine.
c) The actylecholine binds to the receptors on the membrane of muscle fiber and opens the voltage gated sodium channels.
d) Opening of these channels leads to flow of large quantities of sodium ions into the muscle fiber which ultimately results in initiation of action potential in muscle fiber.
e) This action potential depolarizes the fiber including the T-tubules, triggering the release of calcium ions from sarcoplasmic reticulum.
f) The calcium ions thus released initiated the process of muscle contraction.
Answer:
Option D = 3.4 g/mL
Explanation:
Given data:
Volume of water = 21.2 mL
Volume of water + object = 27.8 mL
Mass of object = 22.4 g
Density of object = ?
Solution:
First of all we will calculate the volume of object.
Volume of object = Volume of water+ object - volume of water
Volume of object = 27.8 mL - 21.2 mL
Volume of object = 6.6 mL
Density of object:
d = m/v
d = 22.4 g/ 6.6 mL
d = 3.4 g/mL
