If a farmer wants to increase the health of his crops, he could apply a nitrogen-based fertilizer. why is nitrogen important to plants? a. nitrogen is a primary component of glucose sugar. b. nitrogen is the only element that plants need. c. nitrogen controls the uptake of water through plant roots. d. nitrogen is needed to build proteins and enzymes.

D. Nitrogen is needed to build proteins and enzymes.

Nitrogen is an essential element which is not produced inside the plant body but the plant life and metabolism is largely dependent on this element. All plants obtain the nitrogen from the soil. Nitrogen is required by the plants for the production of chlorophyll, which is required for the process of photosynthesis, synthesis of amino acids which are the building blocks of proteins , and nucleic acids. The amino acids and nucleic acids are required by the plants for proper growth and metabolism. Several enzyme composition is also based upon the nitrogen which performs functions in the cellular and molecular metabolisms.

Therefore, according to the above information Nitrogen is needed to build proteins and enzymes is the correct option.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.