Biology

Seeds generally require oxygen, moisture, and a suitable temperature to germinate, but light is not always necessary. Many seeds can germinate in darkness, so they can germinate in the absence of light.

Gastric juice is secreted by the glands located in the stomach, which aids in digestion by breaking down food.

Involuntary muscles are muscles that work without conscious control. They are found in internal organs such as those in the digestive system, where they help move food along the tract automatically.

The contraction and expansion of the walls of the food pipe (esophagus) to move food is called peristaltic movement. This wave-like muscle contraction helps push food toward the stomach after partial digestion.

Phytoplankton are photosynthetic organisms that release molecular oxygen into water as a byproduct of photosynthesis, unlike E.coli, Amoeba, or Salmonella, which do not produce oxygen.

The brain does not contain involuntary muscles; it is composed of nervous tissue. Involuntary muscles are found in the digestive system, blood vessels, and the heart (cardiac muscle).

The white bellbird (Procnias albus) is recognized as the world's loudest bird, with calls reaching up to 125 decibels, louder than a rock concert. This surpasses the loudness of peacocks and pihas, making option A correct.

The human heart is a myogenic heart, meaning its contractions originate from the heart muscle itself rather than from nervous stimulation. This intrinsic rhythmicity distinguishes it from neurogenic hearts, which rely on nervous input to beat.

The masseter muscle, located in the jaw, is considered the strongest muscle in the human body relative to its weight because it can exert a very high force for its size, enabling powerful biting and chewing.

A rhinoscope (or nasoscope) is specifically designed to examine the inside of the nose, making option B the correct answer. It is a thin, tube-like instrument used by medical professionals to inspect nasal passages.