Biology (Part-V) (Railway)

• A female cannot get pregnant if she doesn't ovulate because there is no egg to be fertilized.

• Oral contraceptive also works by thickening the mucus around the cervix, which makes it difficult for sperm to enter the uterus and reach any eggs that may have been released.

• Besides removing urea and uric acid from the blood, the kidneys also help in maintaining the water and salt concentration in it.

• This process is called as osmoregulation.

• The first site of protein digestion is stomach.

• In stomach the pepsin is secreted as an inactive zymogen form pepsinogen which is converted into active pepsin on exposure to gastric hydrochloric acid.

• The leaves of Nettle, an herbaceous plant that grows in the wild, have stinging hair, which causes painful stings when touched accidentally.

• This is due to the methanoic acid secreted by them.

• Having a blood pressure greater than 140/90 mm Hg is considered high blood pressure or hypertension.

• When volcanoes erupt they emit a mixture of gases and particles into the air.

• These gases include carbon dioxide, sulphur dioxide etc. that are very harmful.

• Glycolysis is the first stage of respiration and is common forboth aerobic and anaerobic respiration.

• It converts Glucose C₆H₁₂O₆, a 6 carbon compound to 2 molecules of Pyruvate (C₃H₄O₃).

• After glycolysis, Its product (pyruvate) gets converted into different compounds depending on the absence of oxygen, lackof oxygen or presence of oxygen.

• A cow needs more area so that it has more time to absorb nutrients from the food it isdigesting.

• The embryo axis shows radicle and plumule, (as shown in the figure), the radicle is future root and the plumule is future shoot.

• The food is stored in cotyledons.

• Walls of sclerenchyma are lignified, which make them thick.

• These tissues cause the plant to become hard.