Question 18 of 20 : Select the best answer for the question.
18. How has the use of herbicides affected agricultural productivity?
O A. Fewer pesticides are needed because of parasitoids.
OB. Fewer people are needed to weed because of herbicides.
O C. Fewer crops are produced because of herbicides.
O D. Fewer crops are organic because of the use of Bt toxin.
O Mark for review (Will be highlighted on the review page)

B. Fewer people are needed to weed because of herbicides.

Explanation:

Herbicides are chemical substances specifically used to control the widespread growth of weeds i.e unwanted plants. Using herbicides has been useful in eradicating the weeds that pose a great threat to agricultural productivity.

Since chemical control (herbicides) has proven to be a faster and effective method, fewer people are needed to involve in the physical control of weeds i.e. weeding. Hence, the use of herbicides has affected agricultural productivity by helping to reduce the amount of laborers.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.

i believe the answer is snake.