Explanation

The diameter of an atom is in the order of 0.2 nanometers (nm), or 200 picometers (pm), which is equivalent to 2 x 10^-10 meters.

Explanation

Most proteins are made up of 20 different amino acids.

These 20 amino acids are commonly referred to as the standard or proteinogenic amino acids.

While other amino acids exist, they are not typically found in the primary structure of proteins that make up most living organisms.

Explanation

Explanation

Small intestine is the primary site for nutrient absorption into the bloodstream.

It contains villi and microvilli, which increase the surface area for efficient absorption of digested food.

Explanation

In fish, ammonia is the chief excretory waste.

Fish excrete ammonia directly into the water through their gills.

Ammonia is toxic, but since fish live in water it gets diluted quickly, making it safe for excretion in this form.

Explanation

The direction of energy flow in an ecosystem is unidirectional, moving through various trophic levels successively.

It begins with the input of solar energy, which is captured by primary producers, such as plants, through photosynthesis.

Explanation

Chromosomes are thread-like structures in the nucleus carrying genetic information (DNA).

They determine an organism’s traits and heredity.

Explanation

Explanation

Explanation

1 kilowatt hour (kWh) = 1000 watts × 3600 seconds

1 kWh = 1,000 × 3,600 = 3,600,000 joules (J)