One Word Substitution

A philistine is a person who is hostile or indifferent to culture, arts, and literature. Lowbrow refers to something uncultured rather than the person themselves in standard strict phrasing, while duffer and jingoism have entirely different meanings.

Jekyll and Hyde refers to Robert Louis Stevenson's characters representing dual personality - good and evil sides of the same person. Daredevil takes risks, maniac is mentally deranged, sadist enjoys inflicting pain.

Lackey means a servile person who obeys orders unquestioningly, fitting the description of someone who never refuses tasks. Simpleton is foolish, gullible is easily deceived, novice is inexperienced/beginner.

Enigma refers to someone mysterious or difficult to understand, fitting a person who carries mystique. Precocious shows advanced development early, suave means smoothly charming, queer means strange/odd.

Jaywalk means to cross roads carelessly or illegally. Though technically a verb, it's the intended answer. Gait is walking manner, drooler is literal, sturdy means strongly built.

Amateur refers to someone who engages in a sport or activity for pleasure rather than as a profession. Novice is inexperienced/beginner, hobby is the activity itself, recluse lives withdrawn from society.

The question asks about strange habits but foible actually means a minor weakness or quirk in character. Among the options, it's closest but imprecise. Loony means crazy, glut means excess, mania is obsession.

The correct answer is altar... Apostle is a messenger/ missionary. Choir is group of singers and sacrilege is the intentional disrespectful treatment of a person.  

Dotage refers to the period of old age, specifically when a person shows characteristics associated with childhood or acts foolishly. It describes the physical or mental decline that sometimes accompanies aging, often manifesting as childish behavior.

A milliner is a person who makes, designs, or sells women's hats. This is a specific occupational term derived from the word 'Milan' (Italy), which was famous for high-quality hat-making. The other options are unrelated occupations or terms.

Reticent means disinclined to talk or reveal one's thoughts; it describes someone who prefers silence over speech. A dandy is overly concerned with appearance, rustic means rural/unsophisticated, and urbane means sophisticated/courteous.

 Bijou means a jewel, something small and exquisite. 

The author means that "in spite of great alterations", the structures or organs that show main change in connection with this adaptive divergence are identified as corresponding.

Thanatophobia is the clinical term for irrational fear of death (from Greek 'thanatos' meaning death). Sceptics doubt claims without evidence. Atheists lack belief in deities. Age is unrelated to specific phobias. Thanatophobia is the precise psychological term.

Lexicographer is the professional term for dictionary compilers/editors (from Greek 'lexicon' - dictionary, 'grapher' - writer). Pedants emphasize minor rules. Theists believe in deities. Age is irrelevant. Lexicography is the specialized craft of dictionary-making.