Biology (Part-IV) (Railway)

• This is because white blood cells can squeeze themselves in between other cells, to reach other, infected cells.

• For example, if there is an infection somewhere in the body, they can squeeze themselves through the walls of the blood cells to an inter-cellular space, where the infection is taking place.

• In snails the sex of the individual is determined by the environment.

• If the snail is attached to a female, it becomes a male, and if not, it becomes a female.

• If there are large number of males present during the developmental stages, the individual may develop into a female.

• Mitochondria are energy-producing organelles.

• In first stage of cellular respiration, glucose is broken down in the cytoplasm of the cell in a process called glycolysis.

• In stage two, the pyruvate molecules are transported into the mitochondria, where it is converted into acetyl CoA and then acetyl CoA enters the Krebs cycle.

• Mitochondria conduct this process by oxidisation of glucose products, like- NADH, and pyruvate.

• As the motility of the sperm is suppressed, fertilisation does not happen.

• Sperm movement is interfered with by Cu²+ ions.

• The root apex, shoot apex and many other regions have meristematic tissue. New cells are produced by mitovic divisions of the meristematic cells.

• These cells have cellulosic cells walls, large nucleus and rich in protoplasm. It is called the phase of cell formation or cell division.

• During diastole, oxygenated blood enters from left atrium to left ventricle and deoxygenated blood enters from the right atrium to the right ventricle.

• The urine is then passed through the ureters to the bladder, where it is stored.

• During urination, the urine is passed from the bladder through the urethra to the outside of the body.

• Due to Urochrome pigment the colour of Urine is Yellow.

• They affect the environment by causing littering and stormwater drain blockages.

• Animals may likewise get tangled and suffocate in plastic bags or they can even die by swallowing them.

• They contaminate soil and water resources as they cannot be decomposed by microorganisms.

• 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.

• The growth of the pollen tube towards the ovule occurs in response to the presence of sugars in the style.

• Hence it is an example for chemotropism.