Excretion - 2 (Class - X)

This is the correct option. Renal arteries carry blood containing waste into the kidneys. Renal veins drain pure blood out of the kidneys after filtration. Ureters are the tubes that carry urine from the kidneys to the bladder.

This is the correct answer. Plants get rid of gaseous waste products through stomata in leaves and lenticles in stem. They get rid of stored solid and liquid wastes through shedding of leaves, barks and felling of fruits. They also secrete wastes through gums and resins.

The renal pelvis or pyelum is the funnel-like dilated proximal part of the ureter in the kidney.

Plants get rid of oxygen through their stomatal pores. Air enters the plant through these openings, and contains carbon dioxide and oxygen, which are used in photosynthesis and respiration, respectively.

Urea is the major end product of nitrogen metabolism in humans and mammals. Ammonia, the product of oxidative deamination reactions, is toxic in even small amounts, and must be removed from the body. The urea cycle or the ornithine cycle describes the conversion reactions of ammonia into urea. Since these reactions occur in the liver, the urea is then transported to the kidneys, where it is excreted.

Keratin is an extremely strong protein, which is a major component in skin, hair, nails, hooves, horns and teeth. The amino acids which combine to form keratin have several unique properties, and depending on the levels of the various amino acids, keratin can be inflexible and hard, like hooves, or soft, as is the case with skin.

The urinary bladder is muscular, so it is under nervous control. As a result, we can usually control the urge to urinate.

Diffusion is the tendency of molecules  to spread into an available space. This tendency is a result of the intrinsic thermal energy (heat) found in all molecules, at temperatures above absolute zero. Without other outside forces at work, substances will move/diffuse from a more concentrated environment to a less concentrated environment. The chloride ions from the glomerular filtrate are reabsorbed through diffusion.

Artificial kidneys contain a number of tubes with a semi-permeable lining, suspended in a tank filled with dialysing fluid. This fluid has the same osmotic pressure as blood, except that it is devoid of nitrogenous wastes.

Water is not reabsorbed in ascending limb of loop of Henle. It is impermeable to water.

One quarter of the total blood output from the heart comes to the kidneys along the renal artery. Two renal arteries arise from the abdominal section of the aorta, each artery supplies a lobe of the kidney. The incoming artery divides into four or five branches, eventually forming arterioles, each of which leads to the compact ball of capillaries, called the glomerulus.

The renal pyramids are conical segments within the internal medulla of the kidney. The pyramids contain the secreting apparatus and tubules, and are also known as the malphighian pyramids.

This is the correct option. Lung is used for excretion of carbon dioxide and water vapour produced during respiration. Skin is used for excretion of urea, salt and excess water by means of sweat glands. Liver is used for removal of excess sugar by converting it into glycogen for further use.

Cells are isodiametric, i.e. equally expanded on all sides. They may be oval, round, polygonal or elongated. Nucleus is present and hence, living. The cell walls are thin and made of cellulose. Cytoplasm is dense with a single large vacuole. Intercellular spaces may be present. Parenchyma which contain chlorophyll is called chlorenchyma.  It gives mechanical strength by maintaining turgidity and stores waste products like tanin, gum, crystals and resins.

The descending loop of Henle receives isotonic fluid from the proximal convoluted tubule (PCT). The fluid is isotonic because as ions are reabsorbed by the gradient time system, water is also reabsorbed, maintaining the osmolarity of the fluid in the PCT.