Explanation

• The correct sequence from highest to lowest level of organization is I, VI, V, IV, III, II.

Additional information:

• I. Biosphere (Highest level, encompassing all life on Earth)
• VI. Ecosystem (Community of living organisms interacting with their physical environment)
• V. Species / Population (Group of organisms of the same kind)
• IV. Organ-system (Group of organs working together within an organism)
• III. Cell (The basic structural and functional unit of life)
• II. Atom (Lowest level, the fundamental unit of matter)

Last verified on 25-10-2026

Explanation

• Cystic fibrosis (CF) is caused by mutations in the CFTR gene, which encodes a membrane protein that transports chloride ions across cell membranes.
• Defective CFTR protein disrupts salt and water movement, producing thick, sticky mucus that commonly affects the lungs and digestive system.
• Cystic fibrosis is an autosomal recessive genetic disorder.
• It means a person generally must inherit a faulty copy of the gene from both parents to develop the disease.

Last verified on 25-10-2026

Explanation

• Thylakoids are flattened membrane sacs inside chloroplasts where the light-dependent reactions of photosynthesis occur.
• Chlorophyll in the thylakoid membranes absorbs light energy, which is converted into chemical energy stored in ATP and NADPH.

Last verified on 25-10-2026

Explanation

• Pepsin is produced in the stomach from pepsinogen and works in an acidic environment.
• Its production is primarily regulated by gastric mechanisms, not secretin.

Additional information:

• Secretin is released by the duodenum in response to acidic chyme entering from the stomach.
• It stimulates the pancreas to release bicarbonate-rich fluid, helping neutralize the acid.
• Trypsin, chymotrypsin, and pancreatic amylase are pancreatic enzymes.

Last verified on 25-10-2026

Explanation

• Chlorophyll a is blue-green.
• It is the primary photosynthetic pigment that directly participates in the light reactions of photosynthesis.
• Chlorophyll b is yellow-green.
• It acts as an accessory pigment, absorbing additional wavelengths of light and transferring the energy to chlorophyll a.
• Both pigments absorb light energy for photosynthesis, but they differ in their light-absorption spectra.

Last verified on 25-10-2026

Explanation

• Cocci are bacteria with a round or oval shape.
• Examples: Staphylococcus, Streptococcus.

Last verified on 26-10-2026

Explanation

Hemophilia is X-linked recessive. Man is XhY and woman is XHXH.

All daughters of this couple get Xh from father and XH from mother. So daughters are XHXh. They are carriers but normal.

Now this carrier daughter XHXh marries a normal man XHY.

Their sons get Y from father and X from mother.

50% sons get XH from mother = Normal

50% sons get Xh from mother = Hemophilic

These sons are the grandsons of the first couple.

So 50% of grandsons will be affected.

Last verified on 25-10-2026

Explanation

• Each amino acid has a specific R-group (side chain) that determines its chemical properties and influences how its carbon skeleton is metabolized.
• During protein metabolism, amino acids undergo deamination, in which the amino group is removed.
• Their remaining carbon skeletons can enter energy-producing pathways at different points.

Last verified on 25-10-2026

Explanation

• The apoplast pathway transports water through cell walls and intercellular spaces without crossing the plasma membrane at every cell.
• At the endodermis, the Casparian strip blocks the apoplast pathway, forcing water to cross a cell membrane before entering the vascular tissue.

Additional information:

• The symplast pathway carries water through the cytoplasm of adjacent cells connected by plasmodesmata.

Last verified on 25-10-2026

Explanation

• The lingual frenulum is a fold of mucous membrane that connects the underside of the tongue to the floor of the mouth.
• It helps stabilize the tongue while allowing movements needed for speaking, swallowing, and eating.

Last verified on 25-10-2026