Explanation

The outer part of the DNA helix is made up of sugar (deoxyribose) and phosphate molecules, which form the backbone of the DNA double helix.

This sugar-phosphate backbone is referred to as the "upright" or "backbone" of DNA.

Explanation

KCl (potassium chloride) is a salt.

Specifically a neutral salt formed by the reaction of an acid (HCl) with a base (KOH).

Explanation

The eyepiece lens has a shorter focal length compared to the objective lens.

It typically around 1-2 cm.

Explanation

CN (cyanide ion) is a Lewis base.

Because it donates an electron pair to form a coordinate covalent bond.

Explanation

In angiosperms, the 3N (triploid) zygote develops into the endosperm, a nutrient-rich tissue that surrounds and nourishes the embryo in the seed.

The endosperm is formed when the fertilized central cell of the embryo sac (3N) divides and grows.

Explanation

Sensory hair cells are specialized cells in the cochlea, the spiral-shaped organ of hearing in the inner ear.

These hair cells convert sound vibrations into electrical signals that are transmitted to the brain, allowing us to hear.

Explanation

Hormones are chemicals released by endocrine cells or glands.

That are carried through the bloodstream to reach distant cells, organs, or tissues, where they regulate various physiological processes.

Explanation

The internal environment, also known as the "milieu intérieur," refers to the conditions within an organism's body.

Such as temperature, pH, and concentration of essential nutrients and waste products.

Explanation

Water (H₂O) is a polar solvent due to its asymmetrical molecular structure.

It results in a slightly positive charge on the hydrogen atoms.

A slightly negative charge on the oxygen atom.

Explanation

Approximately 70% of the Earth's surface is covered with water.

This includes oceans, seas, lakes, rivers, and other bodies of water.