Explanation

Primary consumers are animals that eat producers (plants) and are the first level of consumers in a food chain. They are also known as herbivores. Examples of primary consumers include:

• Insects (bees, butterflies, ants)
• Small mammals (cows, goats, rabbits, mice, squirrels)
• Birds (finches, sparrows, robins)
• Fish (some species of fish that eat algae or aquatic plants)

Explanation

The recommended daily intake of Vitamin A for boys aged 13-15 years is around 5000 IU.

This helps in growth, vision, and immune function during adolescence.

Explanation

Photosynthesis absorbs CO₂ from the atmosphere, reducing greenhouse gases.

Other factors like ozone depletion, greenhouse effect, and CO₂ increase contribute to global warming.

Explanation

Elephants have 56 chromosomes in total, which means 28 pairs.

These chromosomes carry genetic information essential for their growth, reproduction, and survival.

Explanation

The Hindbrain is divided into three main parts:

• Medulla Oblongata (controls breathing, heart rate, and blood pressure)
• Pons (involved in controlling sleep and arousal)
• Cerebellum (coordinates movement, balance, and learning)

Explanation

 A healthy heart beats around 72 times per minute, which translates to roughly 100,000 beats per day. 

Explanation

 The eustachian tube is not part of the inner ear; the inner ear consists of the cochlea, semicircular canals, and the vestibule (which includes the utricle and saccule). 

Explanation

 Ligaments are tough, fibrous bands of connective tissue that connect bone to bone, primarily around joints, helping to stabilize them and limit excessive movement. 

Explanation

The respiratory center, responsible for controlling breathing, is primarily located in the medulla oblongata and pons within the brainstem. 

Explanation

A glucoside bond (glycosidic bond) is a type of covalent bond that links sugar molecules in disaccharides and polysaccharides.

Lactose, a disaccharide, consists of glucose and galactose joined by a β-1,4-glycosidic bond.