Explanation

Aphakia is defined as the "absence of the lens from its normal position."

This condition typically occurs after surgical lens removal, often due to cataract surgery.

As a result of aphakia, the eye loses its ability to focus light onto the retina properly, leading to significant refractive error and visual impairment.

Explanation

The incubation period of influenza, is the time between exposure to the virus and the onset of symptoms

typically ranges from 1 to 4 days, with an average of about 2 days.

Explanation

• Arachidonic acid is converted into three different types of signaling molecules, including prostaglandins, thromboxanes and leukotrienes, all of which are classified as eicosanoids.
• Arachidonic acid is a 20-carbon fatty acid with four carbon-carbon double bonds.

Explanation

Cholesterol is a vital precursor in the biosynthesis of:

Vitamin D:

• Cholesterol converts to 7-dehydrocholesterol in the skin, which forms vitamin D₃ under UV light.

Steroid Hormones:

Cholesterol is the backbone for:

• Sex hormones (testosterone, estrogen, progesterone).
• Adrenal hormones (cortisol, aldosterone).

Explanation

Each mesophyll cell in a leaf typically contains about 20 to 100 chloroplasts, depending on the plant species.

These chloroplasts are the site of photosynthesis, capturing sunlight to produce food.

Explanation

The central requirement in the maintenance of an organism is homeostasis, which is the ability to maintain a stable internal environment despite external changes.

This involves regulating various internal conditions such as body temperature, blood pH, and fluid balance to ensure optimal functioning. 

Explanation

According to Erwin Chargaff's 1951 findings, the ratio of adenine (A) to thymine (T) in DNA is approximately 1:1.

This means that for every adenine molecule, there is a corresponding thymine molecule.

This observation, along with the similar 1:1 ratio of guanine (G) and cytosine (C), forms the basis of Chargaff's rules. 

Explanation

Regeneration is the biological process by which animals regrow lost or damaged tissues, organs, or limbs.

Examples include starfish regenerating arms or lizards regrowing tails after injury.

Explanation

Glycogen gives a red-brown or reddish-blue color with iodine, not pure blue like starch does.

This reaction occurs due to the helical structure of glycogen, which traps iodine molecules and results in a characteristic color—typically brown to reddish-blue.

Explanation

Phagocytic white blood cells (like macrophages) actively engulf and digest pathogens using lysosomes.

These cells have a high number of lysosomes, making them ideal for studying lysosomal activity and function.