GSC101 Final Term Past Papers

GSC 101 Final Term Past Paper · GSC 101 · Total question: 52 · Subjective: 12 · Objective: 40 MCQs

One from each lecture mostly came from final term lectures.

1. What is brine? (2)

Answer: In this method aqueous solution of sodium chloride (common salt) is electrolyzed. The aqueous solution of NaCl is called brine.

2. Difference between prokaryotic and Eukaryotic cell?(3)

Answer: Prokaryotic Cell Vs Eukaryotic Cell

Prokaryotic Cells

Eukaryotic Cells

•  No defined nucleus but a nucleoid region  Defined nucleus with nuclear membrane
•  No membrane bound organelles  Membrane bound organelles are
•  Small in size (e.g. 1-2 microns in bacteria)  Larger than prokaryotic cells on average (20 microns of animal cells)
•  Cell wall consist of peptidoglycan (a polymer of amino acids and sugars)  Cell wall consist of cellulose (plants) and chitin (fungi)

3. Difference between cellular respiration and organismic respiration?(3)

Answer: Difference between cellular and organismic respiration

•  Cellular respiration is a series of events of metabolic reactions for production of energy.
•  Organismic respiration is the process of coordinated movements of body that results in inhalation and exhalation of air. We also call it breathing or ventilation.

4. Define ecology? And flow of energy in ecosystem?(5)

Answer: Ecology is the study of interactions among organisms and their environment.

•  The study of interactions between organisms with each other and their
•  Biosphere and environment.
•  Surface of Earth’s crust
•  Water bodies on Earth’s surface
•  Atmosphere that surrounds Earth

Energy Flow in Ecology

Main source of energy in an ecosystem is “Sunlight”. Autotrophs (producers) are the organisms which utilize the energy stored in inorganic compounds and use sunlight to make their food. These organisms carry out “photosynthesis” and use this energy to convert “carbon dioxide and water into oxygen and glucose”. The other type of autotrophs makes carbohydrates using chemical energy e.g., many bacteria. These are called chemoautotroph. Heterotrophs (consumers) are the organisms that cannot make their own food and depends upon organic source.

5. Label the diagram of lungs? (3)

6. Define food web? and explain the food web in grassland ecosystem through flow chart?(5)

• A network of eating and being eaten.
• Feeding relationships between organisms are not as simple as food chains.
• There is a diversity of organisms and one organism may be eaten by more than one other organisms.
• Example is grass is eaten by cows, buffaloes

Example of a food web from land (grassland) ecosystem

• Grassland ecosystem has small plants, reptiles, amphibians and mammals.
• Grass is eaten by most of the herbivores.
• Herbivores are eaten by more than one carnivore.

7. Chemical properties of HCL? (3)

Answer: Chemical reactions of HCl:

• Reaction with a base, NaOH or KOH

HCl + NaOH _NaCl + H2O HCl + KOH _KCl + H2O

8. What are the conjugate bases and acids? Explain with suitable example? (5)

Answer: Conjugate acids and bases.

Example:

When HCl is dissolved in water the following reaction occurs. HCl + H2O H3O+ + ClHydronium (H3O+) ion is a conjugate acid whereasClion is conjugate base. Reaction of acids with metals: Al + HCl AlCl3 + H2 Mg + H2SO4 MgSO4 + H2s Fe + H2SO4 FeSO4 + H2 Acid-base reactions: NaOH + HNO3 NaNO3 + H2O KOH + CH3COOH CH3COOK + H2O Reactions of acids with metal oxides: Al2O3 + 6HCl 2AlCl3 + 3H2O 3K2O + 2H3PO4 2K3PO4 + 3H2O