The quadriceps femoris muscle is responsible for extending the leg at the knee joint.

The biceps brachii is primarily responsible for flexing the forearm at the elbow joint.

Smooth muscle is involuntary and is found in the walls of internal organs, facilitating movements such as peristalsis.

Skeletal muscle is striated and under voluntary control, allowing for conscious movement.

Oxygen, Nitrogen, and Hydrogen are all diatomic molecules at room temperature.

Phosphorus is a key component in fertilizers, promoting plant growth.

Carbon is essential for photosynthesis as plants convert carbon dioxide into glucose.

Nitrogen is a key component in fertilizers, essential for plant growth.

All options are even numbers, but 2 is the only prime number.

The pattern is adding 5 each time. 15 + 5 = 20.

10 is an even number; the others are odd.

15 is not a prime number; the others are prime.

9 is the only odd number; all others are even.

This is the Fibonacci series where the next number is the sum of the previous two. 5 + 8 = 13.

The series is a geometric progression where each number is multiplied by 2. Thus, 16 * 2 = 32.

This is the Fibonacci series where the next number is the sum of the previous two. 3 + 5 = 8.

The pattern is multiplying by 3: 3*3=9, 9*3=27, 27*3=81.

The binary system is the foundation of digital electronics and computing, as it represents data in two states.

The binary system is most commonly used in modern computing as it directly corresponds to the on/off states of electronic circuits.

Hexadecimal is most efficient for representing large binary numbers in a compact form, as it condenses four binary digits into one hexadecimal digit.

The hexadecimal system is most efficient for representing large binary numbers due to its compactness.

The hexadecimal system is primarily used for color representation in web design, allowing for a compact representation of RGB values.

The binary system is primarily used in digital electronics due to its two-state nature.

Phosphorus is vital for energy transfer as it is a component of ATP, the energy currency of the cell.

Phosphorus is essential for the formation of nucleic acids (DNA and RNA), which are vital for genetic information and protein synthesis.

Sulfur is essential for the synthesis of amino acids, particularly cysteine and methionine.

Nitrogen is a key component of chlorophyll and is essential for its synthesis, thus playing a crucial role in photosynthesis.

The stomach primarily absorbs water and alcohol, while other nutrients are absorbed in the small intestine.

Proteins are essential for muscle repair and growth due to their role in building and repairing tissues.

Phosphorus is essential for root development and is involved in energy transfer and storage.