Answers:
1.) D
2.) B
The pons plays a crucial role in REM sleep, which is the state of sleep in which dreaming occurs.
Answer: Chemical weathering changes the composition of a rock, while physical weathering does not.
Explanation: The definition of a chemical change is a change that cannot be reversed and is caused by a chemical reaction. In this case, a chemical change to a rock would change the composition of the rock while physical changes may change the appearance of the rock, but not the composition.
Question 1: B: rapid water drainage
As in all animal cells<span>, the </span>cells<span> of the </span>human cheek<span> do not possess a </span>cell<span> wall. A </span>cell<span>membrane that is semi-permeable surrounds the cytoplasm. Unlike plant </span>cells<span>, the cytoplasm in an animal </span>cell is<span> denser, granular and occupies a larger space. The vacuole in an an animal </span>cell is<span> smaller in size, or absent.</span>
<u>Answer:</u>
<em>Six centromeres are observed in a prophase cell from an insect, there are </em><u><em>20 pairs of chromosomes present</em></u><em>. </em>
<u>Explanation:</u>
<em>Centromeres is defined as the part of the DNA</em> which are held responsible for the directional changing of chromosomes.
And these chromosome gets divided into <em>2 daughter cells while undergoing the process of mitosis and meiosis. </em>
<em>Chromosome is basically defined as a thin structure</em> as of a threadlike which is made out of nuclei acid and protein which is <em>located at the nucleus of various living cells</em>
