Science [1 Mark Questions]

As in multicellular organisms, all the cells are not in direct contact with environment, simple diffusion does not meet the requirement of all the body cells to get sufficient oxygen.

1. Arteries.
2. Veins.

Vena Cava.

We boil the leaf in Alcohol to remove all its green pigment called chlorophy ll.

A fish has single circulation of blood and a frog has double circulation of blood.

Urinary bladder is a bag which stores the urine temporarily till it is excreted out.

A is glucose and B is starch.

The process of removal of toxic waste from the body of an organism is called excretion. The excretory unit of a kidney is called nephron.

Aerobic respiration.

Nitrogen, phosphorus, iron and magnesium.

The human lungs have been designed to maximise the exchange of gases as there are millions of alveoli in the lungs which provides a large surface area for the exchange of gases.

Valves stop the blood from flowing backward through the heart.

Sunlight and chlorophy ll.

No.

Amoeba.

Digestive enzymes.

Chloroplast.

Alveoli.

Urinary bladder.

Blood.

Carbon dioxide and Water.

When air passes through the nasal passage, the dust particles and other impurities present in it are trapped by nasal hair and mucus so that clean air goes into the lungs.

Saprophytic – Fungi. Parasitic – Plasmodium. Holozoic – Human Beings.

Heart.

Food is the basic requirement of living organisms for obtaining energy.

Chloroplast.

Photosynthesis.

The conditions necessary for autotrophic nutrition are sunlight, chlorophyll, carbon-dioxide and water.

In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.

Yeast can live without oxygen.

Blood circulatory system and lymphatic system.

The mode of nutrition in amoeba is holozoic.

X is sunlight energy and Y is chemical energy.

Root hairs.

Green Plant.

1. Carnivores.
2. Herbivores.
3. Omnivores.

Peristaltic movement.

Urethra is a tube which passes out the urine from the body collected in the urinary bladder.

Absorption of digested foods occurs mainly in the small intestine due to the presence of a large number of finger like projections called villi.

Stomata.

1. The largest artery in the human body is ‘Aorta’.
2. The largest vein in the human body is ‘Vena Cava’.

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

Sphygmomanometer, device used to measure blood pressure, It has a cuff which is tied on the arm of the patient and then the blood pressure is monitored by observing the rise and fall in the mercury level.

Villi.

1. Small Intestine.
2. Large Intestine.

Chemical Energy.

Salivary amylase is present in human saliva. It digests starch. Which of the organs perform the following functions in humans?

1. Absorption of food.
2. Absorption of water.

Ingestion, digestion, absorption, assimilation, egestion.

1. Phloem.
2. Xylem.

Ethanol.