Explanation

• All electromagnetic waves travel through a vacuum at 3x10^8 m/s.
• This is the speed of light (c).
• Radio waves, microwaves, visible light, X-rays and gamma rays all have the same speed in vacuum.

Last verified on 31-10-2026

Explanation

• Earth's magnetic field varies in both strength (magnitude) and direction from place to place.
• Its direction changes with geographic location and is not the same at the magnetic equator and poles.
• Its strength is generally weaker near the magnetic equator and stronger near the magnetic poles.

Last verified on 31-10-2026

Explanation

• Salmonella Typhi is the bacterium responsible for typhoid fever.
• It is a Gram-negative, rod-shaped bacterium.
• It spreads through food or water contaminated with the feces of an infected person.
• Common symptoms include prolonged fever, headache, weakness, abdominal pain, and digestive problems.
• Typhoid can be prevented through safe drinking water, proper sanitation, handwashing, and vaccination.

Last verified on 31-10-2026

Explanation

• Hemophilia is an inherited bleeding disorder caused by deficiency or dysfunction of blood-clotting factors.
• Hemophilia A is caused by deficiency of clotting Factor VIII.
• Hemophilia B is caused by deficiency of clotting Factor IX.
• These factors are essential for normal blood clot formation.
• Common symptoms include prolonged bleeding, easy bruising, and bleeding into joints and muscles.

Last verified on 31-10-2026

Explanation

• The hypothalamus acts as the body's temperature-regulating center.
• When core body temperature rises, it triggers vasodilation of blood vessels near the skin.
• Vasodilation increases blood flow to the skin, allowing more heat to escape.
• Sweating helps cool the body through evaporation of sweat from the skin.

Last verified on 31-10-2026

Explanation

• The term carbohydrate comes from the idea of “hydrated carbon.”
• In many simple carbohydrates, hydrogen and oxygen occur in an approximate 2:1 atomic ratio, the same ratio found in water (H₂O).
• For example, glucose has the molecular formula C₆H₁₂O₆, with 12 hydrogen atoms and 6 oxygen atoms.

Last verified on 31-10-2026

Explanation

• Succinate is oxidized to fumarate by the enzyme succinate dehydrogenase.
• During this reaction, FAD accepts hydrogen and electrons and is reduced to FADH₂.
• Succinate dehydrogenase is also known as Complex II of the electron transport chain.
• FADH₂ carries high-energy electrons to the electron transport chain, helping produce ATP.

Last verified on 31-10-2026

Explanation

• Calcium ions (Ca²⁺) act as important chemical signals in many cellular processes.
• Calcium entry into pancreatic beta cells helps trigger insulin secretion.
• Calcium influx into nerve endings triggers the release of neurotransmitters into the synaptic cleft.
• Calcium enables muscle contraction by interacting with regulatory proteins in muscle cells.
• Calcium also contributes to the electrical activity and contraction of the heart.

Last verified on 31-10-2026

Explanation

• The tibia is the larger, medial bone of the lower leg, commonly called the shinbone.

Additional information:

• The bones that are part of the human hind limb (the lower limb or leg) include:

• Femur (Thigh bone)

• Patella (Kneecap)

• Tibia (Shin bone)

• Fibula (Calf bone)

• Tarsals (Ankle bones)

• Metatarsals (Foot bones)

• Phalanges (Toe bones)

Last verified on 31-10-2026

Explanation

• Felix Bernstein explained the ABO blood group system in 1924.
• ABO blood groups are controlled by three alleles: IA, IB, and i.
• IA and IB are codominant, both are dominant over i.

Last verified on 31-10-2026