The cup-shaped part of nephron which receives the glomerular filtrate is called Bowman’s capsule.

Several collecting ducts unite to form larger ducts that empty urine into a calyx at the tip of the renal pyramid. 

Nitrogenous waste substances such as ammonia, urea and uric acid are produced during protein metabolism according to the species. Amino acids are the breakdown products of proteins in the body. Ammonia is the most toxic and requires large amount of water for its excretion. It is excreted as waste product in protozoans, e.g. amoeba, paramecium, sponges, hydra, liver fluke, earthworm, etc. Uric acid is also excreted as waste product by the most insects (e.g. cockroach), land snails (e.g. helix), land reptiles (e.g. lizards), snakes and birds. 

Hemodialysis is the separation of certain substances from blood by use of a selectively permeable membrane.

In unicellular organisms, e.g. amoeba, paramecium, there are no separate excretory organs. They excrete out waste through general body surface through simple diffusion. The biological process involved in the removal of harmful metabolic wastes from the body is called excretion. These metabolic wastes include the nitrogenous materials. Different organisms use varied strategies for this. Many unicellular organisms remove these wastes by simple diffusion. Diffusion is the movement of particles from the region of high concentration to the region of low concentration. Filtration – It is a physical process used to separate solids from liquid or gases. Reabsorption occurs in kidney, which selectively reabsorbs substances like glucose, protein, sodium, which had already been secreted in the renal tubule. These reabsorbed substances return to blood. Translocation is the transport of soluble products of photosynthesis by the food conducting tissues, called phloem. Therefore, simple diffusion is the correct answer.

Renal artery brings the dirty blood containing waste substances into the kidney.  The renal artery, after entering the kidney, divides and redivides forming various afferent renal arterioles. This renal artery brings dirty blood containing waste substances. 

Ureters are long tubes which connect the kidneys with the urinary bladder. Urinary bladder is a muscular sac where urine is stored until the pressure of the expanded bladder leads to urge to pass it out through the urethra.

 Plants get rid off excess water by the process called transpiration. Transpiration is the loss of water in the vapour form from the exposed surfaces of plants like leaves, stem, etc. Waste products may be stored in leaves that fall off. Also, there are other waste products, which are stored as resins and gums in old xylem (water conducting system). Translocation is the means to transport food from leaves to other parts of the plant or transport of water from the roots to other parts of the plant.

Water droplets are formed by the process of transpiration.  The liquid that comes out of tree bark is actually the excretory wastes like resins, gums, alkaloids (wastes obtained from nitrogenous substances), rubber, etc. Plants do not have special excretory system. They excrete out these waste materials through the bark. Cell sap is the liquid that is stored in the cell vacuole and composed of water and sugars.

Oxygen is generated as a waste during photosynthesis in plants.

Waste products are stored as resins in old xylem plants. Some plant wastes are very useful to human beings, e.g. rubber, latex, gum, resins and essential oils like eucalyptus or sandalwood oil. 

The excretory organs of cockroaches are malpighian tubules.

Coxal glands are the excretory organs in spiders.

There is 0% guanine in the excreta of earthworms. Guanine is exclusively found in the excreta of spiders.

In echinoderms, specialised amoebocytes found in the coelomic fluid perform excretion.