Explanation

• In skeletal muscle, each thick myosin filament is surrounded by six thin actin filaments in the hexagonal arrangement.
• Myosin forms the thick filaments, while actin forms the thin filaments in muscle fibres.
• During muscle contraction, myosin interacts with actin to produce movement through the sliding filament mechanism.

Last verified on 02-11-2026

Explanation

• Total Vertebrae: 33
• Cervical Vertebrae: 7
• Thoracic Vertebrae: 12
• Lumbar Vertebrae: 5
• Sacral Vertebrae: 5 (fused) and Coccygeal Vertebrae: 4 (fused)

Additional information:

• Total bones in an adult: 206
• Bones in a newborn: About 300
• Longest bone: Femur
• Shortest bone: Stapes
• Bones in the skull: 22
• Bones in one hand: 27

Last verified on 21-07-2026

Explanation

• ADH is also called Vasopressin.
• It is released from the posterior pituitary gland.
• During dehydration, ADH secretion increases to help the kidneys reabsorb more water.
• It reduces water loss through urine and makes urine more concentrated.
• ADH helps maintain the body's water balance (osmoregulation).

Last verified on 02-11-2026

Explanation

• Xerophytes are plants adapted to survive in dry and desert environments.
• They have adaptations to reduce transpiration (water loss through leaves).
• Thick waxy cuticles, reduced leaf size, and sunken stomata help conserve water.
• Examples include cactus, aloe vera, and date palm.

Last verified on 02-11-2026

Explanation

• Osmoregulation is the process of regulating water and dissolved solute concentrations in cells and body fluids.
• It maintains the proper balance of water and salts inside cells.
• In humans, the kidneys play a major role in osmoregulation by controlling water and salt levels.
• Osmoregulation helps maintain the body's internal balance (homeostasis).

Last verified on 02-11-2026

Explanation

• Mesophytes are plants that grow in environments with a moderate supply of water.
• They cannot tolerate extremely dry or excessively waterlogged conditions.
• Examples include sunflower, maize, and wheat.

Additional information:

• Hydrophytes grow in water.
• Xerophytes survive in dry conditions.
• Halophytes grow in salty environments.

Last verified on 02-11-2026

Explanation

• The urethra is the tube that carries urine from the urinary bladder to the outside of the body.
• The ureters carry urine from the kidneys to the urinary bladder.
• Humans normally have two ureters and one urethra.
• In males, the urethra also carries semen, while in females it carries only urine.

Last verified on 02-11-2026

Explanation

• Tuberculosis, typhoid, pneumonia and cholera are caused by bacteria.
• Tuberculosis is caused by Mycobacterium tuberculosis.
• Typhoid is caused by Salmonella Typhi, while cholera is caused by Vibrio cholerae.
• Bacterial pneumonia can be caused by Streptococcus pneumoniae.

Last verified on 02-11-2026

Explanation

• The renal pelvis is the central, funnel-shaped cavity of the kidney where urine is collected.
• It receives urine from the major calyces and transfers it into the ureter.
• The ureter carries urine from the kidneys to the urinary bladder.
• Each human kidney normally has one renal pelvis.

Last verified on 02-11-2026

Explanation

• Endosmosis is the movement of water into a cell through a selectively permeable membrane.
• Pure water is hypotonic compared to the cell sap, so water enters the plant cell by osmosis.
• The plant cell becomes turgid (swollen and firm) due to the entry of water.
• The cell wall prevents the plant cell from bursting under normal conditions.

Last verified on 02-11-2026