Biology Online Quiz

Veins seen in the leaves, serve the function of transpiration. They are composed of xylem and phloem cells. The vein xylem transports water from the petiole throughout the lamina mesophyll, and the phloem transports sugars out of the leaf to the rest of the plant.

The arsenic problem in India is primarily due to overexploitation of coal. Mining, metal smelting and burning of fossil fuels are the major industrial processes that contribute to arsenic contamination of air, water and soil.

The locomotory organ of Amoeba is Pseudopodia or false feet. Pseudopodia is a temporary or semipermanent extension of the cytoplasm, used in locomotion and feeding by all sarcodine protozoans and some flagellate protozoans.

Chocolates can be bad for health because of a high content of nickel. Nickel is the most abundant toxic metal and its presence creates a serious risk to children's health.

Competition for food, light and space is most severe in closely related species growing in the same area or niche. It is most severe in closely related species growing in the same habitat as these species will have the same niche, type of food they eat and same characteristics, etc.

Carbohydrates can be divided into three main categories: sugar, fiber and starch. Starches are the most commonly consumed type of carbohydrate. Cereal grains and root vegetables are a rich source of starches.

Compared with other types of grains, whole grains are better sources of fiber and other important nutrients, such as vitamin B, iron, folate, selenium, potassium and magnesium.

Endoscopy is an optical instrument used to see inside the alimentary canal. It is a nonsurgical procedure used to examine a person's digestive tract. Using an endoscope, a flexible tube with a light and camera attached to it, the doctor can view pictures of the digestive tract on a monitor.

The hybrid between horse and donkey is called Mule. Usually, it's the male donkey (jack) mating with a female horse (mare) to produce a mule, which can come in either male or female. Due to the odd number of chromosomes, they can't reproduce.

AIDS is a viral disease caused by Human immunodeficiency virus (HIV). When a person becomes infected with HIV, the virus attacks and weakens the immune system. As the immune system weakens, the person is at risk of getting life-threatening infections.