Option “3” is correct. Photosynthesis takes place primarily in leaves and partially in stems. It takes place within specialized cell structures called chloroplasts. A leaf has a petiole or the stalk and a lamina, the flat portion of the leaf. As its area is broad, the lamina helps in the absorption of sunlight and carbon dioxide during photosynthesis. Photosynthesis takes place in the chloroplasts that have chlorophyll present in them. It is the chlorophyll that has chlorophyll present in them. It is the chlorophyll that absorbs light energy from the sun. There are tiny pores called stomata that function as roadways for carbon dioxide to enter and oxygen to leave the plant.
627. Which among the following pairs is not correctly matched?
1. Thiamine – Beri-beri
2. Vitamin D – Rickets
3. Vitamin K – Sterility
4. Niacin – Pellagra
Option “3” is correct. Napthoquinone is the chemical name of Vitamin-K. It is known as anti-hemorrhagic factor. Its sources are green leaves, egg, liver & intestinal bacteria etc. Sterility is related with deficiency of vitamin E.
628. Which of the following converts milk into curd?
1. Bacteria
2. Vitamin
3. Enzyme
4. None of the above
Option “1” is correct. Milk contains protein casein. This protein gives milk its characteristic the white colour. The curd forms because of the chemical reaction between lactic acid bacteria and casein.
629. Which one of the following cells produces antibodies?
