A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these statements explains why the pigweed re-appeared?A) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. B) The herbicide company lost its triazine formula and started selling poor-quality triazine. C) Triazine-resistant pigweed has less efficient photosynthesis metabolism. D) Only triazine-resistant weeds survived and reproduced, so each year more pigweed was triazine-resistant.

A) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species.

Explanation:

Due to constant use of triazine, the weed will build resistance to it over time unlocking the herbicides codes and making it ineffective.

Natural selection will play out allowing this weeds to bring about a sudden change in their genome that will become resistance, this resistance breed is what will then be produced over time because mutation is heritable and the herbicide then becomes ineffective and the weed continues to multiply and increase in volume.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.