Cell: The Unit of Life (last 10 years) Flashcards

Question

25. Select the correct matching in the following pairs: (2015) a. Rough ER – Synthesis of glycogen b. Rough ER – Oxidation of fatty acids c. Smooth ER – Oxidation of phospholipids d. Smooth ER – Synthesis of lipids Grade 11 / Chapter 8 - Cell : The Unit of Life / page 95

Answer 1

d. Smooth ER – Synthesis of lipids NCERT The smooth endoplasmic reticulum is the major site for synthesis of lipid. In animal cells lipid-like steroidal hormones are synthesised in SER. REMEMBER Smooth endoplasmic reticulum (SER) Synthesis of lipid

Answer 2

c. Vacuoles NCERT In Amoeba the contractile vacuole is important for osmoregulation and excretion. In many cells, as in protists, food vacuoles are formed by engulfing the food particles. REMEMBER In Amoeba the contractile vacuole is important for osmoregulation and excretion. The osmotic expansion of a cell kept in water is chiefly regulated by vacuoles Amoeba = contractile vacuole = important for osmoregulation and excretion

Answer 3

a. Rough endoplasmic reticulum, protein synthesis Add an image RER is frequently observed in the cells actively involved in protein synthesis and secretion. They are extensive and continuous with the outer membrane of the nucleus REMEMBER Rough endoplasmic reticulum (RER) Protein synthesis Also, Smooth endoplasmic reticulum (SER) Synthesis of lipid

Answer 4

c. SER NCERT The smooth endoplasmic reticulum is the major site for synthesis of lipid. In animal cells lipid-like steroidal hormones are synthesised in SER. REMEMBER Smooth endoplasmic reticulum (SER) Major site for synthesis of lipids

Answer 5

a. In post translational modification of proteins and glycosidation of lipids NCERT Golgi apparatus is the important site of formation of glycoproteins and glycolipids REMEMBER Golgi apparatus Important site of formation of glycoproteins and glycolipids

Answer 6

c. Lysosomes and Vacuoles SEE THIS QUESTION AND ANSWER AGAIN

Answer 7

b. Enzymes of electron transport are embedded in outer membrane. NCERT - see this question again A. Outer membrane is permeable to monomers of carbohydrates, fats and proteins. (STILL NOT MENTIONED) B. NOT MENTIONED ANYWHERE C. The inner membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix (Figure 8.7) - insert an image D. The matrix also possesses single circular DNA molecule, a few RNA molecules, ribosomes (70S) and the components required for the synthesis of proteins REMEMBER Inner membrane of the mitochondria forms a number of infoldings = cristae The mitochondrial matrix possesses 1. single circular DNA molecule, 2. a few RNA molecules, 3. ribosomes (70S) and the 4. components required for the synthesis of proteins

Answer 8

d. Mitochondrion NCERT They produce cellular energy in the form of ATP, hence they are called ‘power houses’ of the cell. REMEMBER Mitochondria - produce cellular energy in the form ATP - power house of the cell Mitochondrion is a cell organelle which is responsible for extracting energy from carbohydrates to form ATP

Answer 9

c. (A) is true but (B) is false NCERT A. Semi-autonomous organelles B. The mitochondiral matrix also possesses 1. single circular DNA molecule, 2. a few RNA molecules, 3. ribosomes (70S) and the 4. components required for the synthesis of proteins B. The stroma of the chloroplast contains enzymes required for the synthesis of carbohydrates and proteins. It also contains small, double stranded circular DNA molecules and ribosomes. REMEMBER A. Mitochondria and chloroplast are semi-autonomous organelles B. Mitochondria and chloroplast - synthesis of proteins B. The mitochondiral matrix also possesses 1. single circular DNA molecule, 2. a few RNA molecules, 3. ribosomes (70S) and the 4. components required for the synthesis of proteins B. The stroma of the chloroplast contains enzymes required for the synthesis of carbohydrates and proteins. It also contains small, double stranded circular DNA molecules and ribosomes.

Answer 10

d. Grana NCERT insert an image Like mitochondria, the chloroplasts are also double membrane bound. Of the two, the inner chloroplast membrane is relatively less permeable. The space limited by the inner membrane of the chloroplast is called the stroma. A number of organised flattened membranous sacs called the thylakoids, are present in the stroma (Figure 8.8). Thylakoids are arranged in stacks like the piles of coins called grana (singular: granum) or the intergranal thylakoids. REMEMBER A number of organised flattened membranous sacs called the thylakoids, are present in the stroma (Figure 8.8). Thylakoids are arranged in stacks like the piles of coins called grana (singular: granum) or the intergranal thylakoids. The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are: Grana

Answer 11

d. Ribosomes NCERT - see the question again Insert an image Ribosomes are the granular structures first observed under the electron microscope as dense particles by George Palade (1953). They are composed of ribonucleic acid (RNA) and proteins and are not surrounded by any membrane. The eukaryotic ribosomes are 80S while the prokaryotic ribosomes are 70S. Each ribosome has two subunits, larger and smaller subunits (Fig 8.9). The two subunits of 80S ribosomes are 60S and 40S while that of 70S ribosomes are 50S and 30S. Here ‘S’ (Svedberg’s Unit) stands for the sedimentation coefficient; it is indirectly a measure of density and size. Both 70S and 80S ribosomes are composed of two subunits. REMEMBER DNA is not present in: Ribosomes

Answer 12

a. Mesosomes NCERT A specialised differentiated form of cell membrane called mesosome is the characteristic of prokaryotes. They are essentially infoldings of cell membrane A special membranous structure is the mesosome which is formed by the extensions of plasma membrane into the cell. These extensions are in the form of vesicles, tubules and lamellae. They help in cell wall formation, DNA replication and distribution to daughter cells. They also help in respiration, secretion processes, to increase the surface area of the plasma membrane and enzymatic content. REMEMBER Mesosomes perform the function of mitochondria in bacteria

Answer 13

(A) (B) (C) (D) d. (ii) (i) (iii) (iv) A Smooth Endoplasmic Reticulum = ii. Lipid synthesis B. Rough endoplasmic reticulum = i. Protein synthesis C. Golgi complex = iii. Glycosylation D. Centriole = iv. Spindle formation NCERT A. The smooth endoplasmic reticulum is the major site for synthesis of lipid. B. RER is frequently observed in the cells actively involved in protein synthesis and secretion. C. Golgi apparatus is the important site of formation of glycoproteins and glycolipids. D. In animal cells, centrioles also form spindle apparatus during cell division. REMEMBER A. Smooth endoplasmic reticulum (SER) synthesis of lipid B. Rough endoplasmic reticulum (RER) protein synthesis C. Golgi complex/ Golgi apparatus glycosylation / formation of glycoproteins and glycolipids. D. Centriole Spindle apparatus / spindle formation

Answer 14

b. Spindle fibres, Centrioles and Cilia COULDN'T FIND IT IN NCERT - CHECK AGAIN UNDERSTAND THIS

Answer 15

c. Microfilaments COULDN'T FIND IT IN NCERT DIDN'T WRITE IT DOWN CHECK THIS QUESTION

Answer 16

b. A-iv B-ii C-i D-iii A. Centriole = iv. Basal body cilia or flagella B. Chlorophyll = ii. Thylakoids C. Cristae = i. Infoldings in mitochondria D. Ribozymes = iii. Nucleic acids (COULDN'T FIND IT IN NCERT) NCERT A. Centrosome and centriole form the basal body of cilia and flagella that facilitate locomotion B. Chlorophyll pigments are present in the thylakoids C. The inner (mitochondrial) membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix D. Ribozymes = iii. Nucleic acids REMEMBER A. Centriole = Basal body of cilia and flagella B. Chlorophyll = Thylakoids C. Cristae = i. Infoldings in mitochondria D. Ribozymes = iii. Nucleic acids

Answer 17

b. A-iii B-i C-iv D-ii A. Metacentric chromosome: iii. Centromere in the middle forming two equal arms of chromosomes B. Acrocentric chromosome: i. Centromere situated close to the end forming one extremely short and one very long arms C. Submetacentric: iv. Centromere slightly away from the middle forming one shorter arm and one longer arm D. Telocentric chromosome: ii. Centromere at the terminal end NCERT A. The metacentric chromosome has middle centromere forming two equal arms of the chromosome. B. In case of acrocentric chromosome the centromere is situated close to its end forming one extremely short and one very long arm, whereas C. The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm. D. The telocentric chromosome has a terminal centromere. REMEMBER A. Metacentric chromosome = Centromere is in the middle forming two equal arms of the chromosome. B. Acrocentric chromosome = Centromere is situated close to its end forming one extremely short and one very long arm, C. Sub-metacentric chromosome = Centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm. D. Telocentric chromosome = Centromere terminal

Answer 18

d. Mature sieve tube elements possess a conspicuous nucleus and usual cytoplasmic organelles. NCERT A. Many membrane bound minute vesicles called microbodies that contain various enzymes, are present in both plant and animal cells. B. Electron microscopy has revealed that the nuclear envelope, which consists of two parallel membranes with a space between (10 to 50 nm) called the perinuclear space, forms a barrier between the materials present inside the nucleus and that of the cytoplasm C.These nuclear pores are the passages through which movement of RNA and protein molecules takes place in both directions between the nucleus and the cytoplasm. D. Some mature cells even lack nucleus, e.g., erythrocytes of many mammals and sieve tube cells of vascular plants. Would you consider these cells as ‘living’? REMEMBER A. Microbodies - Present in both plant and animal cells B. Perinuclear space - Forms a barrier between the materials present inside the nucleus and that of the cytoplasm C. Nuclear pores - Passages through which movement of RNA and protein molecules takes place in both directions between the nucleus and the cytoplasm. D. Some mature cells even lack nucleus 1. erythrocytes of many mammals 2. sieve tube cells of vascular plants.

Answer 19

b. A-iii B-iv C-i D-ii A. Cristae - iii. Infoldings in mitochondria B. Thylakoids - iv. Flattened membranous sacs in stroma of plastids C. Centromere - Primary constriction in chromosome D. Cisternae - Disc-shaped sacs in Golgi apparatus NCERT A. The inner membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix B. A number of organised flattened membranous sacs called the thylakoids, are present in the stroma C. Every chromosome (visible only in dividing cells) essentially has a primary constriction or the centromere D. Camillo Golgi (1898) first observed densely stained reticular structures near the nucleus. These were later named Golgi bodies after him. They consist of many flat, disc-shaped sacs or cisternae of 0.5µm to 1.0µm diameter REMEMBER A. Cristae - Infoldings in mitochondria B. Thylakoids - Flattened membranous sacs in stroma of plastids C. Centromere - Primary constriction in chromosome D. Cisternae - Disc-shaped sacs in Golgi apparatus

Answer 20

d. Metacentric NCERT The metacentric chromosome has middle centromere forming two equal arms of the chromosome. REMEMBER Metacentric chromosome = centromere in the middle Forming 2 equal arms of the chromosome

Answer 21

c. Nucleolus NCERT The nuclear matrix or the nucleoplasm contains nucleolus and chromatin. The nucleoli are spherical structures present in the nucleoplasm. The content of nucleolus is continuous with the rest of the nucleoplasm as it is not a membrane bound structure. It is a site for active ribosomal RNA synthesis. REMEMBER Nucleolus - site for active ribosomal RNA synthesis The biosynthesis of ribosomal RNA occurs in: Nucleolus

Answer 22

b. p-arm and q-arm respectively NCERT - COULDN'T REALLY FIND IT / CHECK AGAIN REMEMBER The shorter arm of a submetacentric chromosome = p arm The longer arm of a submetacentric chromosome = q arm

Answer 23

d. It is a site for active ribosomal RNA synthesis NCERT The nuclear matrix or the nucleoplasm contains nucleolus and chromatin. The nucleoli are spherical structures present in the nucleoplasm. The content of nucleolus is continuous with the rest of the nucleoplasm as it is not a membrane bound structure. It is a site for active ribosomal RNA synthesis. REMEMBER Nucleolus - site for active ribosomal RNA synthesis The biosynthesis of ribosomal RNA occurs in: Nucleolus

Answer 24

d. Acrocentric NCERT In case of acrocentric chromosome the centromere is situated close to its end forming one extremely short and one very long arm REMEMBER Acrocentric chromosome = Centromere situated close to its end forming one extremely short and one very long arm The chromosomes in which centromere are situated close to one end are: Acrocentric chromosome

Answer 25

b. Rough endoplasmic reticulum NCERT RER is frequently observed in the cells actively involved in protein synthesis and secretion. They are extensive and continuous with the outer membrane of the nucleus. REMEMBER RER = continuous with the outer membrane of the nucleus. Nuclear envelope is a derivative of: Rough endoplasmic reticulum (RER) UNDERSTAND THIS QUESTION AND ANSWER AGAIN

Answer 26

c. RNA and protein synthesis COULDN'T FIND THIS IN NCERT DIDN'T WRITE IT DOWN

Answer 27

a. A-(iii) B-(iv) C-(i) D-(ii) A. Thylakoids = iii. Flat membranous sacs in stroma B. Cristae = iv. Infoldings in mitochondria C. Cisternae = i. Disc-shaped sacs in Golgi apparatus D. Chromatin = ii. Condensed structure of DNA - COULDN'T FIND THIS NCERT A. A number of organised flattened membranous sacs called the thylakoids, are present in the stroma B. The inner membrane forms a number of infoldings called the cristae (sing.: crista) towards the matrix C. Camillo Golgi (1898) first observed densely stained reticular structures near the nucleus. These were later named Golgi bodies after him. They consist of many flat, disc-shaped sacs or cisternae of 0.5µm to 1.0µm diameter D. Chromatin = ii. Condensed structure of DNA REMEMBER Thylakoids = Flattened membranous sacs in stroma Cristae = Infoldings in mitochondria C. Cristernae = Disc shaped sacs in Golgi apparatus D. Chromatin = ii. Condensed structure of DNA