Science [1 Mark Questions]

Fat is present in the form of large globules. For the concerned enzyme, it is difficult to digest large globules of fat. Emulsification of fat results in fat breaking into smaller globules. After that, it becomes easier for the enzyme to digest fat.

Blocked Stomata: It decreases the rate of photosynthesis by reducing gaseous exchange and non-cooling of leaves due to reduced transpiration.

Guard cells.

1. The teeth serve the function of mechanical digestion by chewing and grinding.
2. Three pairs of salivary glands in mouth secrete saliva which contain bicarbonate ions and salivary amylase. Salivary amylase starts the chemical digestion of starch into maltose in mouth itself.
3. Tongue serves in mixing of food with saliva.

Blood flow through vein does not exert pressure on the walls of veins. Due to this, they do not need thick walls. Hence, veins have thin walls as compared to arteries.

When soil moisture is high, movement of water and dissolved minerals from soil into root hair and finally to the root xylem cells build up root pressure which in turn pushes the water up the xylem vessels. The increased soil moisture and the high root pressure causes increased rate of water absorption which in turn forces water droplets to come out from stomata. Stomatal transpiration creates transpiration pull which in turn carry the water and minerals up in stem thereby decreasing root pressure.

Mucus protects the stomach from corrosion by HCl and pepsin of gastric juice. In the absence of mucus, the lining layer of stomach wall will be corroded forming gastric ulcers. There will be excessive acidity and extreme discomfort.

No Rainfall: Rate of photosynthesis decreases due to wilting of leaves, closure of stomata and reduced availability of hydration.

Photosynthesis.

Autotrophs.

Plants remain fixed at a place because they do not need to move in search of food. As a result, plants do not need to have locomotion, the way animals do. Moreover, most of the movements of substances in plants happen through passive transport; which does not need energy. Due to this, the energy requirement in plants is low as compared to animals.

Significance of transpiration:

1. It creates transpiration pull to facilitate ascent of sap.
2. Ascent of sap is necessary to make water available for photosynthesis.
3. It helps a plant to get rid of excess water.

Heterotrophs.

Nutrition is required by every organism for various purposes. An organism needs energy to carry out various metabolic activities, and this energy comes from nutrients present in food, which is the most potential source of nutrition.

Peristalsis is rhythmic contraction of muscular wall of alimentary canal which in turn pushes the food along the alimentary canal. Peristalsis begins in the esophagus and continues in all the organs of the alimentary canal.

1. Stomatal transpiration removes the gaseous waste of respiration and photosynthesis.
2. Most of waste products are stored in large central vacuoles. Shedding of old senescing leaves help eradication of these wastes from the plant body.

Chloroplast.

Cloudy Days: Photosynthesis is reduced due to low light intensity.

Adenosine Triphosphate (ATP) is called the energy currency in living organisms. It is produced in mitochondria during respiration.

Good Manuring: Rate of photosynthesis increases as good manuring increases soil fertility by providing more minerals, moisture and aeration.

All of them are parasites. They live on or inside the body of another organism to get food. They always harm their hosts.

Blood platelets are a source of thromboplastin which is essential for blood clotting at the place of injury. In the absence of blood platelets, blood clotting will be litde resulting in greater loss of blood from the place of injury.

Pepsin.