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Life Processes

The inner lining of stomach is protected by one of the following from hydrochloric acid. Choose the correct one
(a) Pepsin
(b) Mucus
(c) Salivary amylase
(d) Bile

06/11/2024

Science

10th

Life Processes

If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected?
(a) Proteins breaking down into amino acids
(b) Starch breaking down into sugars
(c) Fats breaking down into fatty acids and glycerol
(d) Absorption of vitamins

06/11/2024

Science

10th

Life Processes

Which is the correct sequence of parts in human alimentary canal?
(a) Mouth → stomach → small intestine → oesophagus→ large intestine
(b) Mouth →oesophagus → stomach → large intestine→ small intestine
(c) Mouth → stomach → oesophagus → small intestine→ large intestine
(d) Mouth → oesophagus → stomach → small intestine→ large intestine

06/11/2024

Science

10th

Life Processes

Select the correct statement
(a) Heterotrophs do not synthesise their own food
(b) Heterotrophs utilise solar energy for photosynthesis
(c) Heterotrophs synthesise their own food
(d) Heterotrophs are capable of converting carbon dioxide and water into carbohydrates

06/11/2024

Science

10th

Life Processes

In which of the following groups of organisms, food material is broken down outside the body and absorbed?
(a) Mushroom, green plants, Amoeba
(b) Yeast, mushroom, bread mould
(c) Paramecium, Amoeba, Cuscuta
(d) Cuscuta, lice, tapeworm

06/11/2024

Science

10th

Life Processes

Which of the following statements about the autotrophs is incorrect?
(a) They synthesise carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll
(b) They store carbohydrates in the form of starch
(c) They convert carbon dioxide and water into carbohydrates in the absence of sunlight
(d) They constitute the first trophic level in food chains

06/11/2024

Science

10th

Periodic Classification of Elements

Give an account of the process adopted by Mendeleev ′ for the classification of elements. How did he arrive at “Periodic Law”?

06/11/2024

Science

10th

Periodic Classification of Elements

Which group of elements could be placed in Mendeleev’s ′ Periodic Table without disturbing the original order? Give reason.

06/11/2024

Science

10th

Periodic Classification of Elements

An element X of group 15 exists as diatomic molecule and combines with hydrogen at 773 K in presence of the catalyst to form a compound, ammonia which has a characteristic pungent smell.
(a) Identify the element X. How many valence electrons does it have?
(b) Draw the electron dot structure of the diatomic molecule of X. What type of bond is formed in it?
(c) Draw the electron dot structure for ammonia and what type of bond is formed in it?

06/11/2024

Science

10th

Periodic Classification of Elements

An element X which is a yellow solid at room temperature shows catenation and allotropy. X forms two oxides which are also formed
during the thermal decomposition of ferrous sulphate crystals and are the major air pollutants.
(a) Identify the element X
(b) Write the electronic configuration of X
(c) Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals?
(d) What would be the nature (acidic/ basic) of oxides formed?
(e) Locate the position of the element in the Modern Periodic Table.

06/11/2024

Science

10th