Asthma is categorized as a(n) a. type of acute tracheobronchial obstruction. b. infective pulmonary disorder. c. restrictive pulmonary disorder. d. obstructive pulmonary disorder.

Option D

Explanation:

Asthma is an obstructive pulmonary disorder in which there the bronchial tubes are extra sensitive. The passage of airways becomes inflammed and produces excess of mucous.

Asthma is generally triggered by dust particles or allergens which is found in the air. It is a very common problem and if affects many people around the world.

The people suffering from asthma must avoid dusty and smoky places to avoid or reduce asthmatic attacks.

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.

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.