Biology (Part-V) (Railway)

• Testes are located outside the abdominal cavity in the case of males because the synthesis of sperms requires 2-3°C lower than normal body temperature.

• So, it is enclosed by a sac-like structure called the scrotum, which helps testes maintain the required temperature.

• The exact causes of high blood pressure are not known, but several things may play a role, including: smoking, being overweight, lack of physical activity, stress, etc.

The Bloodpressure of healthy man is 120/80.

• Transpiration:  Gaseous wastes and water are excreted through stomata, lenticels of the stem, and the outer surface of stems, fruits, etc.

• Storing:  Some organic wastes are stored in plant parts such as barks and leaves.

Diffusion:  Aquatic plants excrete metabolic wastes through diffusion. Terrestrial plants excrete into the soil.

• Being the basic units of ventilation, they help with rapid oxygen and carbon dioxide exchange.

• Oxygen from the air enters into a leaf through stomata and reaches all the cells by the process of diffusion.

• This oxygen is used in respiration in cells of the leaf.

• Then the fertilized egg (embryo) or eggs are transferred to a uterus.

• One full cycle of IVF takes about three weeks.

• Each gamete contains only one version of each factor (sex cells are now recognised to be haploid)

• Parents contribute equally to the inheritance of offspring as a result of the fusion between randomly selected egg and sperm

• This force creates waves that radiate outward in all directions away from their source, sometimes crossing entire ocean basins.

• The transport of water in the xylem takes place only from the roots to the leaves.

• Therefore, the movement of water and nutrients in the xylem is unidirectional.

• Being selective in nature, they are known as selectively or differentially permeable membranes.

• All living biological membranes are selectively permeable membranes.