Answer:
Immunity to Small Pox
Explanation:
Over the years, Europeans had built up an immunity to smallpox because many had contracted the disease and still survived. As the population grew children were born with some immunity to the disease. When the Europeans arrived in the Americas, and smallpox spread around the native peoples, the Europeans did not contract the disease because they were immune. However, since the natives were not immune, they slowly died of due just to the disease as well as some parts of the war between the europeans.
Answer:
It reflects the amount of force an object exerts
Explanation:
A newton is a unit of force that will accelerate one kilogram of mass one meter per second squared.
Answer:
The correct option is option A
Explanation:
Restriction enzymes are endocleases that cleave DNA fragment (<u>of usually four, five or six nucleotide long</u>) at <u>specific sites to produce blunt or sticky ends</u>. They <u>recognize palindromic sequences of host DNA when cleaving the specific sites</u>. The sequences below (on complementary strands) give an example of a palindromic sequences.
5'-CCC║GGG-3'
3'-GGG║CCC-5'
As can be seen above, when read from 5' to 3', the two sequences are the same despite being on opposing strands. And when cut between the guanine (G) and cytosine (C) (as shown above), it produces a blunt end. But when cut as shown below produces a sticky end.
5'- G║AATTC -3'
3'- CTTAA║G -5'
The explanation above shows options C and D are right while option A is wrong (hence the correct option).
Also, bacteria prevent their own DNA from been digested by restriction enzymes by adding methyl group to their restriction sites <u>which prevents restriction enzymes from recognizing restriction sites of their DNA;</u> this generally makes bacterial DNA to be highly methylated. This explanation makes option B right also.
Answer:
Bees play a significant role in the field of agriculture. They can adapt to the process of pollination. Pollination is usually defined as the process of transportation of pollen grains from the male anther of a flower to the female stigma. The bees pollinate the crops and increases their productivity and yield capacity. About 35% of the food that we eat, are dependent on this pollination act that is carried out by the bees, involving either directly or indirectly.
Over the last few decades, the population of the bee has been decreasing, and it is directly affecting the global human population. It is because less amount of food is produced compared to the rate of demand, resulting in a shortage of food items.
The respiratory system and the circulatory system function together as a “coupled unit” delivering the body's oxygen and nutrients and taking away carbon dioxide and wastes to maintain homeostasis.
