Answer:
weed means which feed on plants and takes nutrients from them weed also stops the growth of plant
so we have to uproot weed
Answer:
hydrogen and oxygen combine explosively in a single raction
Explanation:
The reason is Molecules of hydrogen react with oxygen violently to break the initial molecular bonds and form new one between the atoms of the two elements. The reaction results into an explosive release of energy and the production of water because the products of the reaction are at a lower energy level
It is false I think or true but I am sure it is not true
Answer:ways Water enters the atmosphere evaporation, transpiration, excretion and sublimation:
Explanation:
Transpiration is the loss of water from plants (via their leaves).
Sublimation is when ice or snow transforms directly into water vapour without going through a liquid phase (i.e. they do not melt).
Animals excrete water by respiration and by passing urine.
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.
Answer:
1. Signaling molecule
2. Signaling receptors
Explanation:
Hormones, growth factors, neurotransmitters, etc. serve the function of signaling molecules for cells. These molecules are released by one cell and bind to the receptors present on/in the target cells to elicit the desired response. Thereby, the signaling molecules serve in cell-cell communication.
For example, insulin hormone synthesized and released from beta cells of pancreas binds to its cell surface receptors present on the surfaces of liver cells and muscle cells to stimulate the uptake of the glucose from the blood.
Likewise, neurotransmitters released from the presynaptic neuron bind to receptors present on the membrane of postsynaptic neuron and serve to carry the nerve impulse to the postsynaptic neuron.
