Answer: Colonial organisms are the result of many identical individuals joining together to form a colony. These cells are partly dependent on each other to start with. But, later evolutionary events resulted in the obligatory relationships among them resulted in multicellularity.
Answer:
<u>1. type IV hypersensitivity: delayed-type hypersensitivity. </u>
<u>2. type I hypersensitivity: IgE </u>
<u>3. type II hypersensitivity: IgG </u>
<u>4. type III hypersensitivity: immune complexes </u>
Explanation:
Type IV hypersensitivity is cell mediated hypersensitivity rather than antibodies as in all other types of hypersensitivities. It is also known as delayed type hypersensitivity because it usually respond in 2-3 days via T-Lymphocytes rather than antibodies like IgE or IgG. So we can say that in option 5 is mismatched as it relates type IV to IgG antibodies.
Answer: Several types of evidence supported Hess's theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves. This evidence led scientists to look again at Wegener's hypothesis of continental drift.
Explanation:
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.
Answer: they are on diffrent parts of the chain
Explanation:
