Explanation

After 1 half-life = half remains = N/2

After 2 half-life = half of N/2 remains = N/4

Last verified on 25-10-2026

Explanation

• X-rays are also known as Roentgen rays.
• It named after German physicist Wilhelm Conrad Röntgen, who discovered them in 1895.
• X-rays are a form of electromagnetic radiation with high energy and short wavelengths.
• They can pass through soft tissues.
• The are widely used in medical imaging.

Last verified on 25-10-2026

Explanation

• Force is defined as the rate of change of linear momentum with respect to time.
• According to Newton’s second law, force causes a change in an object’s momentum.

Last verified on 25-10-2026

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