Explanation:
Tests for gases
Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.
Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.
Oxygen. A glowing wooden splint relights in a test tube of oxygen.
Answer:
Explanation:
The cell membrane separates the cell from the outer environment. The extracellular fluid contains the sodium ions (Na+), chloride ions (Cl-), while intracellular fluid contains potassium (K +) and negative anions.
The potential difference arises when the membrane is selectively permeable to some ions. The resting potential is -70mV.
When the neurons get excited, the sodium ions start to enter by sodium channels.
Now there are more positive ions inside the cell membrane. It disturbs the resting potential i.e. -70mV. This stage is known as depolarization.
When the inside environment of the cell is more positively charged, the potassium ions start to move out of the cell. It goes out by the voltage-gated channels. Thus resting stage is maintained and it is known as repolarization.
But the initial stability of the cell membrane has to be maintained. To restore the resting stage, the sodium ions start to move out of the membrane and potassium ions enter into the cells again. This is an active transport and has done by the Na+ - K+ pump. Here 3 sodium ions move out and 2 potassium ions pumped into the cell through the plasma membrane.
Thus the resting potential regains. The potassium ions come back into the cells against the concentration gradient and ATP provides the energy for this phenomena.
Terms matched with the right definitions.
1. An organism that can make its own food – Autotroph
2. A symbiotic relationship between two organisms in which one species benefits and no effect is apparent to the other species – Commensalism.
3. A cell that has a membrane-bound nucleus and/or organelles as its major characteristic -Eukaryote.
4. The study of organisms that are too small to be seen with the naked eye - Microbiology.
5. A disease-causing organism - A germ pathogen.
6. A one- or few-celled organism with chromosomes; may have characteristics of both animals and plants – Protist.
An autotroph is an organism that produces its own food from simple substances available in its environment. Autotrophs usually use inorganic chemical reactions or light energy in producing their food and are usually the producers in a food chain. Examples of autotrophs are plants and algae.
Commensalism is a type of relationship between organisms of two species where one organism benefits from the relationship and the other organism is not affected by it (neither benefits nor harmed).
The function of a protein is determined by its shape. The shape of a protein is determined by its primary structure (sequence of amino acids). The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it.
