Yellow-fruit nightshade

This plant is called yellow-fruit nightshade or कन्टकरी. Its botanical name is Solanum virginianum. This thorny herb grows in wild, on roadside and near farms. 

It bears beautiful, purple flowers and brinjal-like fruit. 

It is considered to be a poisonous plant. However, it has several medicinal uses also.

Factors Affecting Photosynthesis

According to Blackman's law of limiting factors, if a chemical process is affected by more than one factor, then the rate of reaction will be determined by the factor which is nearest to its minimal value.

Photosynthesis is affected by factors like light intensity, carbon dioxide concentration, temperature and water. 

1. Light: if light increases, photosynthesis also increases upto a certain level. Then it remains constant. Plants need only 10% of the available light intensity of sunlight. Therefore, light is never a limiting factor except in case the plant is in shade or in dense forest. 

If the light intensity increases too much, it starts destroying the chlorophyll, thus, photosynthesis reduces. 

2. Carbon dioxide: if amount of carbon dioxide increases, photosynthesis also increases upto CO2 concentration of 0.05 %. Then photosynthesis reduces. 

Saturation level or optimum level of carbon dioxide for C4 plants is 360 microlitre per litre of air; and for C3 plants is 450 microlitre per litre of air. Thus, carbon dioxide is a limiting factor more for C3 plants. 

3. Temperature: if temperature increases, photosynthesis also increases upto a certain level. Then photosynthesis reduces. C3 plants have lower optimum temperature (18 to 24 degree celsius). C4 plants have a little higher optimum temperature (30 to 40 degree celsius). 

4. Water: if available water is more, photosynthesis increases up to a certain level. Then there is no effect. If water available is less, the stomata do not open fully. So absorption of carbon dioxide is less. Thus, photosynthesis will also be less. 

Camels of Rajasthan (India)

These are the camels of Rajasthan. The zoological name of camel is Camelus dromedarius. These are very large, strong and handsome creatures. They are reared mainly for milk and to carry load. Once they were abundant in this area but now they are in crisis. Their number is decreasing and they now need support. 

Squirrel

This is a northern palm squirrel (Funambulus pennantii). It has five black-brown stripes on its back. It lives on trees. It is quite active and playful creature. Children like to observe it sitting, playing or searching for food. It doesn't sit in one place; though in summer, it likes taking rest on wet ground in the shade of a tree.