Unicellular organisms are made up of only one cell that carries out all of the functions needed by the organism, while multicellular organisms use many different cells to function.
Answer:
D. None of the above
Explanation:
<u>Reason that Drastic Change in weather may cause mass extinction</u>
Weather plays an important role in the survivability & the growth/diminish of the population. For example, animals that need large amounts/bodies of water (for example fishes), will not survive when the area is hit with a heat wave & drought, which would cause fishes to surface, and die.
<u>Reason that Geological change would play a large role in mass extinctions</u>
While the Geography is constantly changing, large abrupt changes would cause a upheaval and may upset the population, leading to a depletion of resources or even a sudden destruction of part/all of the population. For example, an earthquake may kill large amounts of animals, and the destruction of the greenery in the area may severely limit the amount of food/decrease the primary consumer's populations, leading to a starvation.
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Answer:
The correct answer is - tight junctions.
Explanation:
Tight junctions are one of the cell-cell junctions that make a barrier to the passage of material which is a present in epithelia. This barrier is impermeable to most of the materials with soluble molecules. This barrier is made up of the occludin and claudin proteins.
Tight epithelia have tight junctions and examples of such junctions are the distal convoluted tubule or DCT, and the collecting duct of the nephron in the kidney.
Thus, the correct answer is - tight junctions.
