Tag: zoology

Iron is particularly problematic in paper manufacturing because it causes staining and discoloration of the paper product.

Detergents that are released from the domestic sewage, as well as the industrial effluents, are the causative pollutants because these result in the increasing the inorganic mineral quantity in the water body. Because of this, the eutrophication occurs. The dissolved oxygen in the water body is decreased and the aquatic life suffers from the hypoxia. Plastic, glass junk and iron junk persist in nature as they are non-biodegradable. Their downhill causes are less as compared to the detergents.

Detergents are the chemicals that have an efficient cleaning ability due to the surfactants present in them. In order to provide the whitening effect, detergent contains bleach. Their are optical brightening substances called fluorescers also present. The perborates are added in the detergents as they provide effective oxidizing property. However, all these chemical are nondegradable in natue and tend to persist in the environment. Hence, the correct answer is ‘All of the above’.

Thermal pollution refers to the water pollution caused by the discharge of the hot industrial effluent in the water body that destroys the ambient temperature of the water body. The thermal pollution is a major water pollution near the coal power plants that use water as the coolant so that it absorbs the thermal energy from the thermal plants and then the hot water is released in the nearby water body. The rise in temperature of the water causes severe adverse effects to the aquatic life.

The eco-friendly detergents are free from the added chemicals, instead they have enzymes to catalyse the reactions. They do not contain phosphates, bleaches, synthetic perfumes, brightening chemicals etc. They contain lipases and proteases that break down the fats and proteins, so they are effective in stain removal. Hence, the correct answer is 'Phosphates and bleaches'.

Umbilical cord is a narrow, tube-like structure that connects the fetus to the placenta.Through this tube, nutrients and oxygen are supplied from the mother to the baby and waste products are removed from the baby.

Prolactin is secreted by the anterior lobe of pituitary gland. After parturition, secretion and storage of milk in mammary glands is under the influence of this hormone.

Placenta is an intimate connection between the fetus and uterine wall of the mother to exchange the materials. Food materials and oxygen pass from the mother's blood into the fetal blood and fetal excretory products diffuse into maternal blood through placenta.

The human placenta is both metadiscoidal and monodiscoidal. Discoidal refers to the structure of the placenta and mono meaning there is only one disc. Metadiscoidal refers to the way the developing placenta becomes discoidal- the villi are scattered at first and then restricted to one disc, that means the placenta becomes mono-discoidal.