<span>A protonephridia is known as a flame cell because it is a specialized excretory cell. This simply means that these cells have the ability to remove waste materials within an organ of a particular living organisms. Some freshwater invertebrates, flatworms, and rotifers have these specialized cells within their systems.<span>
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Answer:
This question is incomplete as it lacks options, however, it will be answered BROADLY so the it can be understood enough to select the correct answer.
Please find the explanation below
Explanation:
Cells perform different functions and look differently because of the process of CELL DIFFERENTIATION. All cells arise from a single stem cell, which then gradually differentiates into different types of cells with different functions, as they divide.
At the molecular level, these different types of cells contain the same DNA sequence as rightly stated in the question. However, they look and perform differently because some of the genes are turned on while the others are turned off via the process of GENE EXPRESSION.
Therefore, a blood cell and skin cell possess exactly the same DNA sequence but look different and perform different functions because of CELL DIFFERENTIATION in which some genes on the DNA sequence are expressed and others are repressed. For example, in the blood cell; the genes coding for certain proteins found in blood are expressed while every other gene is silenced or inhibited. This allows those cells to perform only blood-related functions.
Answer:
B
Explanation:
The folds contain ribosomes attached to the membrane. The more the folds the more the surface area to which more ribosomes can attach. The ribosomes are organelles responsible for the manufacture of protein in cells. Thereafter, the proteins are properly folded by the mediation of chaperones in the lumen of the RER.
In Pavlov's original studies on classical conditioning, he used dogs as the subject of his experiment. The unconditioned stimulus was the <u>bowl of food</u> that he presented to the dog while the unconditioned response was the dog salivated in its excitement to see the food.
The first box is migration
The second box is the northern regions have become warmer because of climate change
