CBSE Class 11 Biology HOTs Cell And Its Structure

MULTIPLE CHOICE QUESTIONS

Question. Which chromosome may lost during cell division? 
(a) Giant chromosome
(b) Acentric chromosome
(c) Polycentric chromosome
(d) Telocentric chromosome
Answer. B

Question. Which of the following is responsible for mechanical support and enzyme transport ?
(a) Dictyosome
(b) Cell membrane
(c) E. R.
(d) Mitochondria
Answer. C

Question. DNA is present in
(a) chromosomes and dictyosomes
(b) chloroplasts and lysosomes
(c) mitochondria and chloroplasts
(d) mitochondria and endoplasmic reticulum 
Answer. C

Question. Three of the following statements regarding cell organelles are correct while one is wrong. Which one is wrong? 
(a) Lysosomes are double membraned vesicles budded off from Golgi apparatus and contain digestive enzymes.
(b) Endoplasmic reticulum consists of a network of membranous tubules and helps in transport, synthesis and secretion.
(c) Leucoplasts are bound by two membranes, lack pigment but contain their own DNA and protein synthesizing machinery.
(d) Sphaerosomes are single membrane bound and are associated with synthesis and storage of lipids.
Answer. A

Question. In many bacteria, cell membrane is invaginated and folded to form
(a) pili
(b) cristae
(c) flagella
(d) mesosome
Answer. D

Question. Which of the following is present between cell walls of the plant cells ? 
(a) Lomasome
(b) Microsome
(c) Lysosome
(d) Middle lamella
Answer. D

Question. The phagocytosis was first of all seen by
(a) Huxley
(b) Haeckel 
(c) Metchnikoff
(d) Darwin
Answer. C

Question. A chromosome with centromere at one end is called
(a) telocentric
(b) metacentric
(c) excentric
(d) apocentric
Answer. A

ASSERTION REASON QUESTIONS 

Directions : These questions consist of two statements, each printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following five responses.
(a) If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
(b) If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
(c) If the Assertion is correct but Reason is incorrect.
(d) If both the Assertion and Reason are incorrect.
(e) If the Assertion is incorrect but the Reason is correct.

Question. Assertion : Power house of cell is mitochondria.
Reason : ATP is produced in mitochondria.
Answer. B

Question. Assertion : Cell wall is not found in animal cell.
Reason : Animal cells are covered by cell membrane.
Answer. A

Question. Assertion: Organisms are made up of cells.
Reason: Cells are structural unit of living organisms. A cell keeps its chemical composition steady within its boundary. 
Answer. A

Question. Assertion: Specialization of cells is useful for organism.
Reason: It increases the operational efficiency of an organism. 
Answer. A

Question. Assertion: The number of cells in a multicellular organism is inversely proportional to size of body.
Reason: All cells of biological world are alive.
Answer. D

Question. Assertion : Eukaryotic cells have the ability to adopt a variety of shapes and carry out directed movements.
Reason : There are three principal types of protein filaments-microfilaments, microtubules and intermediate filaments, which constitute the cytoskeleton. 
Answer. B

Questions:

Question. What are the shortcomings of Scheleiden &Schwan theory? Who modified it and how?
Answer. They did not explain the arise of new cells .Rudolph Virchow modified it and stated that cells arise from the pre existing cells.

Question. Differentiate between structure of flagella and centriole?
Answer. Structure of flagella : nine plus Two arrangement ; sub tubules are in doublet Structure of Centriole : Nine plus Zero arrangement of sub tubules are in triplet.

Question. Why nucleolus is larger in actively working cell?
Answer. Nucleolus are involved in actively synthesizing RNA. That will ultimately result in protein formation.