Answer:
Cells vary greatly in shape These shapes are often related to the function they perform. like the disk shape of erythrocytes can absorb and transport oxygen due to increased surface area., the amoeboid shape of leukocytes allow them to squeeze through capillaries. etc.
Explanation:
Cells can be disc-like , polygonal, rectangular, cubopid thread like branched or even irregular. these are related to the functions that each cell performs.
Some examples showing relation between cell shape and function are as follows.:
- Human blood cells are circular and biconcave to transport oxygen.
- White blood cell are amoeboid to squeeze through thin capillaries.
- Nerve cells are long so that they can carry nerve impulse to a long distance very quickly.
- Guard cells of stomata are bean or dumbell shaped to open and close the stomata.
What do you mean <span>It has been observed that certain species of insects which had not previously caused significant harm have become serious pests. the best explanation for this phenomenon is that the pesticide killed off predators which had previously held this species in check. a mutation occurred in the species. the pesticide increased the vigor of the species. was able to be used by the pest as an additional food source is also a reproductive for some insect species. </span><span />
Results in the formation of 2 cells, each with the same amount of genetic material and the same genetic information.
The event last in 15,600 seconds.
Answer: Option B
<u>Explanation:</u>
We know that there is 60 seconds in one minute i.e., 1 minute = 60 seconds
There is 60 minutes in one hour. i.e., 60 minutes = 1 hour.
Given : An event lasts 4 hours and 20 minutes
4 hours contains 240 minutes,

When the above expressed in seconds,
------>eq. 1
When 20 minutes expressed in seconds,
------->eq. 2
Adding both eq. 1 and 2, we get
4 hours and 20 minutes = 14400 + 1200 = 15600 seconds