Explanation

A hypothesis is a tentative explanation for an observation or a scientific problem.

It is testable through experiments and forms the basis for further investigation.

Explanation

Heterocysts are specialized nitrogen-fixing cells found in some cyanobacteria (e.g., Anabaena).

They provide an anaerobic environment necessary for the enzyme nitrogenase to fix atmospheric nitrogen.

Explanation

The MN blood group system shows co-dominance, where both M and N alleles are equally expressed in the phenotype.

Individuals can have M, N, or MN blood types, with MN expressing both traits simultaneously.

Explanation

The sodium-potassium pump (Na⁺/K⁺-ATPase) actively transports 3 Na⁺ ions out of the cell and 2 K⁺ ions into the cell for each cycle,

For maintaining the electrochemical gradient

Explanation

Nails, feathers, hair, and horns are made up of proteins.

These structures primarily consist of keratin.

Keratin is a type of protein that provides strength and durability.

Explanation

Vitamin B deficiency can cause diseases such as:

• beriberi
• pellagra 
• anemia

Vitamin B12 deficiency anemia happens when your body does not have enough healthy red blood cells

Explanation

• The nucleus is responsible for cell division because it contains chromosomes, which are made up of DNA and proteins.
• Chromosomes carry the genetic information necessary for cell division, growth, and function.

Explanation

The nervous system is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to various parts of the body.

Explanation

Alleles of a gene are located at the same locus on homologous chromosomes.

A locus refers to a specific location or position on a chromosome where a particular gene is located.

Explanation

• Photosynthesis occurs during daytime because it depends on sunlight, which provides the energy necessary for the process to occur.
• Sunlight is the source of light energy that is absorbed by pigments such as chlorophyll.
• Which is then used to power the conversion of carbon dioxide and water into glucose and oxygen.