CELL THE UNIT OF LIFE
2010 March
1. Label the marked parts in the given diagram of a chloroplast.
1. ………………..…….. (½)
2. ………………..…….. (½)
2. (a) Choose from the bracket, the name of the part of a bacterial cell that constitutes extra genomic DNA.
(Mesosome/plasmid/basal body)
(b) Write any one of its functions.
(c) Comment on its practical application.
2010 September
1. Cell membrane is comprised of lipids and proteins. Membrane proteins mediate transfer of molecules across it. (1)
a. Suggest a model of membrane constitution that is suitable for this function.
b. Give the name of scientist who proposed it.
2. State the reasons for the following: (2)
a. Mitochondria are called the powerhouses of the cell.
b. A metabolic product from cytoplasm is needed for energy production in mitochondria.
2011 March
1. A cell with a chromosome number 42 undergoes mitosis and another cell with 42 chromosomes undergoes meiosis. Give the chromosome number of daughter cells after mitosis and meiosis. Give reasons for your answer. (2)
2. Plastids are found in all plant cells and in euglenoids. Draw a diagram of the chloroplast and label the following parts:
a. Grana
b. Stroma
c. Thylakoid
c. Thylakoid
d. Stroma lamella
1. Examine the diagram of a eukaryotic cell. Which one of the labeled cell organelles is present in bacteria? Membrane extensions into the bacterial cell are called mesosomes. What are their forms and function? (3)
2011 October (Improvement)
1. Examine the diagram of a eukaryotic cell. Which one of the labeled cell organelles is present in bacteria? Membrane extensions into the bacterial cell are called mesosomes. What are their forms and function? (3)
2012 March
1. a) Identify the cell organelle found both in eukaryotic and prokaryotic cells. (½)
b) Justify its presence in both types of cells. (½)
2. Match the following: (2)
a) Synthesis and storage of energy i. Golgi apparatus
b) Packaging and delivery of materials ii. Mitochondria
c) Digestion of intercellular materials iii. Centriole
d) Formation of basal body of cilia and flagella iv. Lysosome
v. Chloroplast
2012 September (Improvement)
1. The following is a list of cell organelles (nucleus, endoplasmic reticulum, lysosomes, chloroplast, Golgi complex, mitochondria, ribosome). (3)
a. Identify the organelles with double membrane envelope.
b. Mention the functions of these organelles.
2013 March
1. An accepted model of the structure of a cell membrane was proposed by Singer and Nicolson.
a. Name the model. (½)
b. List the 2 major biomolecules which this membrane is composed of. (1)
c. Mention two important points of this model from the point of view of function. (1)
2013 September-October (Improvement)
1. The diagrams a, b, c given below show three kinds of chromosomes. Of this, which is metacentric non-satallite chromosome? Justify your answer. (1)
2014 March
1. Prokaryotic cells possess a special membranous structure which is formed by the extensions of the plasma membrane in the form of vesicles, tubules and lamellae. Identify this structure and write any one of its functions. (½ + ½ = 1)
2. State whether the statements are ‘true’ or ‘false’. If false, correct the statements by changing the underlined words.
a. Aleuroplasts store carbohydrates.
b. The centrioles form the basal body of cilia and flagella.
c. Ribosomes are not surrounded by membranes.
d. RER is the major site for synthesis of lipids. (4 x ½ = 2)
2014 August (Improvement)
1. In which hydrolases, the membrane bound vesicles are present? (1)
2. Distinguish between the characters of chloroplast and ribosomes from the given list and write them in appropriate columns.
(Double membrane, George Palade, sac-like thylakoid, 70 S and 80 S). (2)
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Chloroplast |
Ribosome |
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|
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2015 March
1. a) Due to the presence of a secondary construction, a knob-like small fragment appears in some chromosomes called
i) Kinetochore ii) Histone iii) Satellite iv) Chiasmata
b) Classify chromosomes based on the position of centromere. (2)
2015 September (Improvement)
1. Several ribosomes may attach to a single mRNA and form a chain called ………….. (1)
2. Name the types of chromosome based on the position of centromere in the figure and label the parts A, B & C. (2)
2016 March
1. Observe the given diagram. Analyze this diagram and explain the structure of plasma membrane. (3)
2017 March
1. a) Identify a cell organelle which contains hydrolytic enzymes.
b) Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER) are morphologically and functionally different. Justify this statement. (3)
2017 July (Improvement)
1. Position of centromere determine the shape of the chromosomes.
a) Name the different types of chromosomes based on the position of centromere.
b) Draw any one chromosome among them. (3)
2018 March
1. Ribosomes are organelles without a membrane found in all cells. Name another organelle devoid of membrane, seen in animal cells. Write its function.