Biology (Part-VIII) (Railway)

• In the second step of fermentation, however, pyruvate is converted to lactic acid by the enzyme lactate dehydrogenase.

• The lack of oxygen leads to lactic acid formation due to the incomplete breakdown of glucose.

• During an injury, platelets will cluster together at the site of the wound to act as a plug, sealing blood vessels in a process called clotting to prevent excess blood from leaving our body.

• Also known as the 'fight or flight' hormone, it helps the body to adjust to stress when one is very angry, embarrassed or worried.

• Hospitals can provide emergency care if complications arise during labor and delivery.

• There is one elongated extension (axon) for sending impulses and usually many branches (dendrites) for receiving impulses.

• The impulses from the axon cross a synapse (the junction between two nerve cells) to the dendrite of another cell.

• When fossil fuels are burned, they release large amounts of carbon dioxide, a greenhouse gas, into the air.

• Greenhouse gases trap heat in our atmosphere, causing global warming.

• These plants accumulate organic acid intermediate during the night to be used during the daytime.

• This pathway is called Crassulacean acid metabolism (CAM).

• One circuit goes through the lungs and back to the heart. which is called pulmonary circulation.

• The other goes throughout the rest of the body and its organs including the brain (systemic circulation).

• Collenchyma cells are found in the secondary phloem of plants.

• Functions of these cells include: protection of the plant against mechanical injury, provide support for the vascular tissue, and acting as a sheath that regulates water flow.

• When HIV destroys this cell. it becomes harder for the body to fight off other infections.

• Without treatment, HIV can lead to other infections and affect the whole body.