They are useful because of the way they process and digest food. They apply their enzymes externally and then absorb smaller mollecules. This process releases things like CO2 or creates alcohols, and this has historically been used in making drinks like beer or foods like bread and cheese.
In human audition, the vibration of the ossicles is triggered by the vibration of the tympanic membrane (the eardrum) and transmitted directly to the fluid and membranes of the inner ear.
The inner ear is shaped like a snail with a thousands of tiny hair cells in it and it is called the cochlea. Hair cells change the vibrations into electrical signals that are sent to the brain through the auditory nerve.
Answer: The correct answer for the first question is- B) Mechanical.
Adaptation can be described as a process of change in an organism over time that facilitates its survival in the changing environmental conditions. It results due to mutation or genetic change in the individual that gives a benefit to the organism. It exhibits change in structure ( like succulent plants in desert), function, or behavior.
Mechanical is not a type of adaptation as it deals with movement of objects.
The correct answer for second question is- C) Variations.
Variation among organisms in a population results from change in the genetic material or their genetic sequences. Change at the genetic level is thus reflected in the phenotypes ( like different color of feathers in birds).
Thus, difference is in the feather color reflects variations.
C. Combine with new atoms
This is how things are made, like oxygen (O2) and hydrogen (h2) combine to make water (H2O)