Assertion: Old ladies are prone to osteoporosis. 
Reason: Oestrogen also maintain calcium balance in the bones and blood.

Assertion: Phylloclades are adaptation for xerophytic habitats. 
Reason: Ruscus, Casuarina have reduced or modified leaves to avoid transpiration.

Assertion: In the hydrophytes, the xylem is not differentiated into different types of cells. 
Reason: Xylem provides support and helps in the conduction of water which are not very important in hydrophytes.

Assertion: Gene expression is a molecular mechanism by which a gene expresses a phenotype. 
Reason: Structural genes are controlled by control genes.

Assertion: Neurohypophysis is situated in the cells of stomach. 
Reason: Neurohypophysis releases vasopressin and oxytocin.

Assertion: Cataract is the condition on which lens become completely opaque. 
Reason: In the condition, a person can see only near objects.

Assertion: Sinus venosus is a thin walled sac with little muscular tissue in primitive heart. 
Reason: It receives venous blood through the hepatic veins.

Assertion: B-cells (Beta cells) account for about 80% of the total number of islet cells. 
Reason: They secrete a hormone called thyroxine.

Assertion: Monotropa grows in pine forests with the roots of pines. 
Reason: Saprophytes obtain their nutrition from dead organic matter.

Assertion: outermost layer of the bone is a fibrous connective tissue. 
Reason: Matrix of bone is composed of protein ossein.