The yellow color of human urine is primarily due to a pigment called urochrome. Urochrome is a waste product resulting from the breakdown of hemoglobin, a protein in red blood cells. The varying shades of yellow in urine can be influenced by factors such as hydration levels, diet, and certain medications, but urochrome is the main pigment responsible for the typical yellow color of urine.

An Admiral of the fleet is a military naval officer of the highest rank. In many nations, the rank is reserved for wartime of ceremonial appointments. It is usually a rank above admiral (which is now usually the highest rank in peace-time for officers in active service) and is often held by the most senior admiral of an entire naval sevice.

A concave mirror is used in a solar cooker. Specifically, a concave mirror focuses sunlight onto a small area, increasing the intensity of the sunlight and generating heat. This concentrated sunlight is then used for cooking in solar cookers, harnessing solar energy for practical applications.

The plants that never produce flowers are called "cryptogams." Cryptogams include plants such as ferns, mosses, liverworts, and algae. Unlike flowering plants (angiosperms), which reproduce through seeds enclosed within flowers, cryptogams reproduce through spores and do not produce true flowers. Cryptogams are considered more primitive in evolutionary terms compared to angiosperms, which are the most dominant group of plants on Earth today.

Flat Mirror (or Plane Mirror): Reflects light without distorting the image. The image formed is erect (upright) and of the same size as the object, but reversed from left to right.

Convex Mirror: Also produces an erect image. The image formed is virtual (cannot be projected onto a screen), smaller than the actual object, and upright.

Both flat and convex mirrors can create upright (erect) images of real objects.