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Biology (NCERT) - Class XI > XI Chap 8 Cell: Unit of Life > Flashcards

XI Chap 8 Cell: Unit of Life Flashcards

1
Q

_________ emphasized the unity underlying the diversity in forms of biological organisms

A

Cell theory

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2
Q

The physico-chemical approach to study of living organisms is called __________________

A

Reductionist Biology

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3
Q

_______ was an outstanding figure in the field of protein structure and founder of the ‘Madras’ school of conformational analysis of biopolumers

A

G N Ramachandran

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4
Q

____________ discovered the triple helical structure of collagen

A

G N Ramachandran

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5
Q

G N Ramachandran was deeply influenced by ______’s publications on models of the alpha-helix and Beta-sheet structures

A

Linus Pauling

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6
Q

______ is the basic unit of life in all organisms

A

Cell

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7
Q

___________ organisms are capable of independent existence and performing the essential functions of life

A

Unicellular organisms

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8
Q

_______ first saw and described a live cell

A

Anton Von Leeuwenhoek

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9
Q

_________ discovered the nucleus

A

Robert Brown

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10
Q

The invention of _________ and _________ revealed all the structural details of a cell

A

microscope and electron microscope

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11
Q

In ______ a German botanist named _______ observed that all plants are composed of different kids of cells

A

1838, Matthias Schleiden

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12
Q

In ________ a British Zoologist _________ studied animal cells and reported that cells had a thin outer layer today known as _________

A

1839,
Theodore Schwann,
plasma membrane

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13
Q

_________ concluded that the presence of cell wall is unique to plant cells

A

Theodore Schwann

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14
Q

Theodore Schwann proposed what hypothesis?

A

that the bodies of animals and plants are composed of cells and products of cells

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15
Q

_______ and _______ together formulated cell theory, What was lacking in this theory?

A

Schleiden and Schwann,

lacking - explanation for how new cells are formed

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16
Q

_____________ explained for the first time in the year ______ that cells divided and new cells are formed from pre-existing ones

A

Rudolf Virchow, 1855

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17
Q

What does omnis cellula-e cellula mean?

A

Every cell from the cell,

cells divide to form new cells

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18
Q

What are the 2 tenets of cell theory?

A
  1. All living organisms are composed of cells and products of cells
  2. All cells arise from pre-existing cells
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19
Q

What are the exceptions to cell theory?

A 
Bacteria, 
Viruses, 
Sieve tube (enucleated), 
RBCs (enucleated),
Rhizopus (multinucleated)
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20
Q

Cells of human cheek have ________ as delimiting structure of the cell, whereas onion cell has ______

A

outer membrane, cell wall

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21
Q

Cell is a ___________ that separates outer and inner environments so that _____________

A

chamber, reactions can continue unperturbed

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22
Q

EVERY cell at some point has DNA which stores info for some reactions and processes inside the cell. T or F?

A

True.

Even RBCs and sieve cells first have DNA then lose it to become enucleated

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23
Q

Cells that have membrane bound nuclei are called _____ whereas those that lack it are called _____

A

eukaryotic,

prokaryotic

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24
Q

Cell membrane is made up of ___________ which makes it __________ (hydrophilic/hydrophobic)

A

lipid, hydrophobic

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25
Q

Only in eukaryotic cells with membrane bound nuclei, a semi-fluid matrix called cytoplasm occupies the volume of the cell. T or F?

A

False, in both eukaryotic and prokaryotic

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26
Q

Prokaryote and eukaryotic cells BOTH have organelles. T or F?

A

True, but prokaryotes have non-membrane bound organelles

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27
Q

Main arena of cellular activities in both plant and animal cells is _________

A

cytoplasm

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28
Q

Various chemical reactions in the cytoplasm of a cell keep it in a _________ state

A

living

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29
Q

In addition to a nucleus, eukaryotic cells have other membrane-bound structures called ______

A

organelles

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30
Q

Endoplasmic reticulum, golgi complex, lysosomes, mitochondria, microbodies and vacuoles are all examples of ______________

A

cell organelles

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31
Q

Prokaryotic cells lack membrane bound organelles. T or F?

A

True

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32
Q

Ribosomes are membrane-bound organelles found in all cells - eukaryotic and prokaryotic. T or F?

A

False, found in all cells yes but NON-membrane bound

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33
Q

Ribosomes are found where in the cell?

A

Cytoplasm, within chloroplasts (in plants), within mitochondria and on rough ER

(in bacteria - associated with plasma membrane)

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34
Q

What is centrosome?

A

Non-membrane bound organelle,
in animal cells,
helps in cell division

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35
Q

Cells differ greatly in ______, ______ and ______

A

size, shape and activities

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36
Q

___________ are the smallest cells only _____ in length

A

Mycoplasma, 0.3 µm (micrometer)

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37
Q

Mycoplasma has ______ (cell wall / no cell wall) and its shape is ________

A

no cell wall, not fixed

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38
Q

Length of bacteria is ________

A

3 to 5 µm

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39
Q

Largest isolated single cell is _________

A

egg of an ostrich

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40
Q

Size of typical eukaryotic cell?

A

10-20 micrometers

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41
Q

Size of viruses?

A

0.02-0.2 micrometer

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42
Q

Size and full-form of PPLO?

A

0.1 micrometer

Pleuro Pneumonia Like Organisms

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43
Q

Human RBCs are about 7.0 µm in radius. T or F?

A

False, in diameter

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44
Q

_______ cells are some of the longest cells in multicellular organisms

A

Nerve

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45
Q

Match the following:

  1. round and biconcave
  2. branched and long
  3. elongated
  4. round and oval
  5. long and narrow
  6. amoeboid

Columnar epithelial cells, Tracheid, Mesophyll, RBC, WBC, Nerve cells

A
  1. round and biconcave - RBC
  2. branched and long - nerve cells
  3. elongated - tracheid
  4. round and oval - mesophyll
  5. long and narrow - columnar
  6. amoeboid - WBC
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46
Q

____ (____m) and _____ (_____m) units are visible in electron microscope but not in compound microscope

A

Nanometer 10^-9

Angstrom 10^-10

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47
Q

____ (____m) and _____ (_____m) units are visible in compound microscope

A

Micrometer 10^-6

Millimeter 10^-3

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48
Q

Some eukaryotic cells measure in millimeters. T or F?

A

True

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49
Q

Shapes of cells vary with the functions they perform. T or F?

A

True

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50
Q

Blue green algae and PPLO are prokaryotic cells. T or F?

A

True

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51
Q

Pick which of these are correct:
Prokaryotic cells are ________ compared to eukaryotic

smaller, have nuclear membrane, multiply rapidly, unique inclusions, no organelles at all

A

smaller, multiply rapidly, unique inclusions

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52
Q

4 basic shapes of bacteria?

A

Bacillus - rod
Coccus - spherical
Vibrio - comma
Spirillum - spiral

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53
Q

Shapes, functions and fundamental organisation of prokaryotic cells vary greatly. T or F?

A

False,
shapes and functions vary greatly
but fundamental organisation is similar

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54
Q

All prokaryotes have a _______ surrounding the cell membrane except _______

A

cell wall, mycoplasma

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55
Q

Genetic material in prokaryotes is held how in the cell?

A

basically naked, not enveloped

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56
Q

Prokaryotes have what all types of DNA?

A
  1. Genomic (single chromosome / circular DNA)

2. Plasmid (small circular DNA outside the genomic)

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57
Q

Plasmid DNA confers _______ to bacteria such as ________

A

unique phenotypic characters, antibiotic resistance

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58
Q

Plasmid DNA is present in _____________ (all / some / none) bacteria and _____________ (all / some / none) eukaryotes

A

some, none

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59
Q

Bacterial DNA is aka _____________ or _____________

A

nucleoid, main genomic DNA

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60
Q

_____________ in bacteria contains the essential genes whereas _____________ contains non-essential genes

A

Nucleoid, plasmid

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61
Q

Plasmid vs genomic DNA. Similarities (2) and differences (3,2)

A

Similarities - double-stranded, circular

Differences -
Plasmid is more than one, extrachromosomal and self-replicating independent of nucleoid
Genomic DNA is singular and naked

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62
Q

Bacterial surface structures are aka cell membrane extensions. T or F?

A

False, cell WALL extensions

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63
Q

A specialized differentiated form of cell membrane called _________ is found in prokaryotes. They are essentially _____ of cell membrane.

A

mesosome, infoldings

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64
Q

Most prokaryotic cells, particularly bacterial cells, have a chemically simple cell envelope. T or F?

A

False, complex

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65
Q

Cell envelope of prokaryotes consists of tightly bound 3 layered structure. What are the layers?

A

(outermost) Glycocalyx > Cell wall > Plasma membrane

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66
Q

Each layer of prokaryotic cell envelope has distinct features and functions. They do not have any coordinated function. T or F?

A

False, they have distinct functions but act together as a single protective unit

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67
Q

Bacteria can be classified into how many groups on basis of cell envelope differences? What are they? How are they identified?

A

2 groups,
Gram positive and Gram negative
Gram positive take up the gram stain, negative don’t

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68
Q

Glycocalyx differs in ______ and _____ among different bacteria

A

composition and thickness

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69
Q

Glycocalyx as a loose sheath is called _____ and as a thick and tough layer is called _______

A

slime layer;

capsule

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70
Q

Glycocalyx is made up of ___________

A

mucopolysaccharides (carbohydrates)

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71
Q

What are the functions of glycocalyx?

A
  1. protects from host immune system
  2. adhesion
  3. prevents loss of water and nutrients
  4. prevents from dessication
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72
Q

What are the functions of the cell wall layer of the cell envelope?

A
  1. Determines the shape of the cell
  2. Provides strong structural support
  3. Prevents bacterium from bursting or collapsing
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73
Q

Cell wall in bacteria is non-cellulosic. T or F?

A

True

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74
Q

Cell wall is made up of _____________ which in turn constitutes (3) things?

A

peptidoglycan

NAG - N-acetyl glucosamine
NAM - N-acetyl muramic acid
Amino acids / peptides

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75
Q

NAM and NAG alternate in cell wall of bacteria and peptide chains form on _________ (NAM / NAG)

A

NAM

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76
Q

What is cross-linking in bacteria?

A

Peptide bonds in cell wall form cross-links - grid-like structure - makes cell wall stronger

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77
Q

Penicillin prevents _____________ in bacteria thereby causing the cell wall to undergo _____________

A

cross-linking,

osmotic bursting

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78
Q

Why does penicilin not kill mycoplasma?

A

Because penicillin works by breaking down cell wall and mycoplasma has no cell wall

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79
Q

________ layer of prokaryotic cell envelope is selectively permeable and similar structurally to that of eukaryotes

A

Plasma membrane

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80
Q

Composition of cell wall in plants vs bacteria vs fungi?

A

Plants - cellulose
Bacteria - peptidoglycan
Fungi - chitin

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81
Q

Cell wall of plants, fungi and bacteria are made up of the same fundamental substance - carbohydrates. T or F?

A

True

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82
Q

_________ cells do not have cytoskeletal elements (threads on the inside providing structural support)

Bacteria or eukaryotic

A

Bacteria

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83
Q

Lysozyme in _______ and ______ in humans destroys bacteria by __________

A

saliva, tears, breaking down cell wall

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84
Q

Archaebacteria is not made up of peptidoglycan. T or F?

A

True

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85
Q

Gram positive bacteria retain the stain and are ______ in color.
Gram negative bacteria are colorless or ______ stain

A

blue, pink

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86
Q

Gram positive vs Gram negative bacteria

Comment on: cell wall/envelope - thin or thick?
amount of peptidoglycan and lipid?
presence of pili and porins

A

Gram positive - thick cell wall/envelope, more peptidoglycan but less lipid, no pilli or porins

Gram negative - thin cell wall/envelope, less peptidoglycan but more lipid, pilli and porins present

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87
Q

Categorize into Gram positive and Gram negative bacteria:

E Coli, Lactobaccillus, clostridium, mycoplasma, cyanobacteria, Frankia, Rhizobium, Streptococcus, Bacillus

A 
E Coli - Negative
Lactobaccillus - Positive
Clostridium - Positive
Mycoplasma - Negative
Cyanobacteria - Negative
Frankia - Positive
Rhizobium - Negative
Streptococcus - Positive
Bacillus - Positive
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88
Q

Cell membrane is made up of a __________ bilayer

A

phospholipid

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89
Q

Cell membrane layer has a ______ head which is __________ (hydrophobic/hydrophillic) and two arms made up of _____ chains that are __________ (hydrophobic/hydrophillic)

A

polar, hydrophilic,

carbon, hydrophobic

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90
Q

Phospholipid in cell membrane is made up of _____ fatty acids and one ____________

A

two, phosphate

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91
Q

Mesosome is formed by extensions of cell wall or plasma membrane into the cell. T or F?

A

False, extensions of plasma membrane only

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92
Q

Mesosome plasma membrane extensions can be in what forms? (3)

A

vesicles
tubules
lamellae

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93
Q

What does mesosome help in? (6)

A

cell wall formation,
DNA replication and distribution to daughter cells,
respiration,
secretion processes,
increase surface area of plasma membrane,
increase enzymatic content

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94
Q

Mesosome is similar in function to _____________ in eukaryotes

A

cristae of mitochondria

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95
Q

What is a unique feature of the cyanobacteria cell envelope?

A

Chromatophores, membranous extensions into the cytoplasm containing pigments

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96
Q

Chromatophores are analogous to _____________ in eukaryotes

A

thylakoid of chloroplasts

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97
Q

Bacterial cells are always motile. T or F?

A

False, can be motile or non

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98
Q

Motile bacterial cells have ______ extensions from the cell wall called flagella

A

filamentous

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99
Q

Non-motile bacteria do not show movement. T or F?

A

False, they move passively (e.g. carried by water)

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100
Q

All bacteria have the same or similar flagella number and arrangement. T or F?

A

False, diverse

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101
Q

What are the 3 parts of a bacterial flagellum?

A
  1. Filament
  2. Hook
  3. Basal body
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102
Q

_________ is the longest portion of the bacterial flagellum. It extends from where to where?

A

Filament,

from cell surface to outside

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103
Q

Flagella of bacteria is made of single thread of _____________

A

flagellan protein

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104
Q

Filament is the largest surface structure in bacteria. T or F?

A

False, flagella

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105
Q

Bacterial and eukaroytic flagella differ in their roles and structural make-up. T or F?

A

False, differ in structural make-up but SAME role of movement

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106
Q

Bacterial flagella vs eukaryotic flagella? (2)

protein and arrangement

A

bacteria - flagellan protein, NO 9+2 arrangement

eukaryote - tubulin protein, 9+2 arrangement

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107
Q

What are the 6 types of flagella arrangement?

A

Monotrichous, Amphitrichous, Peritrichous, Cephalotrichous, Atrichous

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108
Q

Peritrichous has flagella _____________ for example _____________

A

in all directions, E. Coli

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109
Q

Cephalotrichous has flagella _____________ whereas lophotrichous has flagella _____________ (example: _____________)

A

on head, two ends (spirillium)

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110
Q

Atrichous bacteria are _____________ (with/without) flagella and _____________ (motile/non-motile)

Examples? (3)

A

without, non-motile

cyanobacteria, mycoplasma, coccus

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111
Q

Flagella, Pili and Fimbriae are 3 surface structures that play a role in bacterial motility. T or F?

A

False, 3 surface structures but latter 2 don’t play role in motility

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112
Q

Pilli are _________ and ________ surface structures made up of a special protein called _______

A

elongated, tubular, pillin

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113
Q

Fimbriae are _____________, ________-like fibres sprouting out of the bacterial cell

A

small, bristle-like

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114
Q

Role of pilli vs fimbrae

A

Pilli - sexual reproduction / conjugation

Fimbrae - attach to substratum (host or rock)

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115
Q

Fimbrae are less in number compared to pilli which are many in number. T or F?

A

False, other way around

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116
Q

Eukaryotic cells are usually measured in micrometers and some in millimeters. T or F?

A

True

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117
Q

Prokaryotic cells are usually measured in _________meters

A

micro

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118
Q

Size of ribosomes (in nm) in prokaryotic cells?

A

15 nm by 20 nm

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119
Q

What are the two subunits of ribosomes? Together they form?

A

50S and 30S, together form 70S prokaryotic ribosomes

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120
Q

50S is the smaller unit of ribosome whereas 30S is the larger unit. T or F?

A

False, reverse

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121
Q

Ribosomes are the site of ________

A

protein synthesis

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122
Q

Ribosomes are _____________ (membrane-bound or non-membrane bound)

A

non-membrane bound

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123
Q

What is a polysome? aka?

A

Several ribosomes attach to a single mRNA and form a chain, aka polyribosomes

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124
Q

Ribosomes translate mRNA into _____________ and once folded they become proteins

A

polypeptides

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125
Q

First ___S ribosomal subunit attaches to mRNA followed by ___S

A

30S, 50S

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126
Q

Inclusion bodies are soluble small-size organelles that are granular in appearance. T or F?

A

False, insoluble

Rest is correct

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127
Q

Why are inclusion bodies insoluble?

A

So that they take less space in cytoplasm

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128
Q

What are inclusion bodies?

A

reserve material in stored in prokaryotic cytoplasm

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129
Q

Inclusion bodies are not bound by any membrane and lie free in prokaryotic cytoplasm. T or F?

A

True

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130
Q

Examples of inclusion bodies?

A

Glycogen granules, phosphate granules, cyanophycean granules, glycogen granules

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131
Q

________ (type of inclusion body) are found in blue green and purple and green photosynthetic bacteria

A

Gas vacuoles

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132
Q

_____________ are aka pseudovacuoles. Why?

A

Gas vacuoles, they have a membrane (whereas other vacuoles don’t) but the membrane is NOT made up of lipid

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133
Q

Gas vacuoles are a type of _____________ (name of the organelle)

A

inclusion body

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134
Q

Gas. vacuoles are found in plant cells. T or F?

A

False, cyanobacteria

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135
Q

Rank in order of solubility?

Starch, glycogen, glucose

A

Glucose - most soluble
Starch - less
Glycogen - least

136
Q

Eukaryotes include:

A

protists
plants
animals
fungi

137
Q

Four types of plasmid?

A

Resistance “R”
Tumor inducing “Ti”
Fertility “F”
Degenerative

138
Q

What does R plasmid do?

A

Confer antibiotic resistance

139
Q

_____________ plasmid results in uncontrolled cell growth in roots of plants

140
Q

Ti plasmid is present in __________ organism

A

Agrobacterium tumifacien

141
Q

______________ is aka natural genetic engineer

A

Agrobacterium Tumifacien

142
Q

What is the role of F plasmid?

A

transfer of plasmid from one bacteria to another (primitive method of sexual reproduction i.e. conjugation)

143
Q

In conjugation, _____________ bacteria has pilli whereas _____________ does not

A

F+ (male)

F- (female)

144
Q

What is unique about degenerative plasmid? Example of bacteria that contains it

A

Digests oil spills - bioremediation

e.g. Pseudomonas putida

145
Q

There is extensive compartmentalization of cytoplasm in eukaryotes. T or F?

146
Q

Eukaryotes have a variety of complex locomotory and cytoskeletal structures. T or F?

147
Q

Genetic material in eukaryotic cells is organised into ___________

A

chromosomes

148
Q

All eukaryotic cells are identical. T or F?

149
Q

Organelles without membrane vs. double membrane vs. single membrane

A

without membrane:

  1. nucleolus
  2. centriole
  3. ribosome

double membrane:

  1. mitochondria
  2. chloroplast
  3. nucleus

single membrane:

  1. ER
  2. Golgi bodies
  3. lysosome
  4. vesicles
  5. vacuole
  6. peroxisome
  7. cilia/flagells
150
Q

Plant vs. animal eukaryotic cells?

A

Plant - cell walls, plastids/chloroplasts and large central vacuole
Animals - none of the above + have centrioles

151
Q

Cell membrane is present in all cells. T or F?

A

False, all LIVING cells

152
Q

Cell membranes are absent in _____________, _____________ and _____________

A

tracheids, vessels, fibres

dead cells

153
Q

Why did we chemically study cell membrane of RBC?

A

Because RBCs do not contain organelles that could be confused for cell membrane (no golgi, ER, mitochondria or nucleus)

154
Q

Detailed structure of the cell membrane was only studied after the advent of ______ in the _____

A

electron microscope, 1950s

155
Q

Phospholipids are _____________ i.e. they have non-polar and polar parts

A

amphipathic

156
Q

Chemical studies on cell membrane (before advent of electron microscope) enabled scientists to deduce ________

A

possible structure of the plasma membrane,

cell membrane is mainly composed of lipids and proteins, also contains carbohydrates

157
Q

Chemical studies to study cell membrane before the advent of the electron microscope were conducted on which cells?

A

Human RBCs

158
Q

Major lipids are _________ arranged in a ______ in cell membrane

A

phorpholipids, bilayer

159
Q

Lipids in cell membrane have ________ oriented towards the outer side and _________ oriented towards the inner part

A

polar head,

hydrophobic tails

160
Q

What does the orientation of lipid head and tail ensure?

A

Nonpolar tail of saturated hydrocarbons is protected from aquaeous environment

161
Q

Cell membrane contains cholesterol. T or F?

162
Q

Ratio of protein to lipid is consistent across different cell types. T or F?

A

False, varies

163
Q

Protein-lipid ration in human RBCs?

A

52% (protein) to 40% (lipid)

164
Q

Depending on __________ membrane proteins can be classified as integral and peripheral.

A

Ease of extraction

165
Q

Peripheral proteins lie _____ while integral proteins lie ________

A

peripheral - on surface of membrane

integral - partially or totally buried in membrane

166
Q

In mitochondria, F1 complex is an example of a _____________ protein whereas F0 complex is an example of a _____________ protein

A

peripheral, integral

167
Q

_____________ proteins are more common in plasma membrane (integral vs peripheral)

A

Peripheral

168
Q

Cholesterol provides _____________ to cell membrane

169
Q

Cholesterol is present in _____________ and _____________ cells and absent in _____________

A

animal cells, mycoplasma

absent: plant

170
Q

_____________ (specifically _____________) on cell membrane act as antigens

A

Glycoproteins, sugar chains

171
Q

What is Singer and Nicolson’s model of cell membrane? When was it proposed?

A

1972, fluid mosaic model,

quasi-fluid nature of lipid enables lateral movement of proteins within the overall bilayer

172
Q

_____________ is the measure for fluidity within the membrane

A

ability to move within the membrane (greater lateral movt => more fluid)

173
Q

6 functions that fluid nature of plasma membrane helps in?

A
  1. Cell division
  2. Cell growth
  3. Endocytosis (phagocytosis-eating + pinocytosis-drinking)
  4. Exocytosis (cell vomiting)
  5. Making intercellular junctions
  6. Transport of molecules (active and passive)
174
Q

Why can’t dead cells undergo plasmolysis?

A

Because they do not have a cell membrane

175
Q

One of the most important functions of the cell membrane is __________

A

transport of molecules across it

176
Q

According to the Singer and Nicolson model, proteins are like _____________ and phospholipids are like the a _____________

A

icebergs, sea

177
Q

Proteins only exhibit lateral movement within cell membrane, whereas lipids can move: (3)

A

laterally, flip flop or rotational

178
Q

Plasma membrane contains ______-______% proteins and ______-______% lipids

A

20-70% proteins

20-80% lipids

179
Q

Other than proteins and lipids, cell membrane contains carbohydrates, enzymes and water. T or F?

180
Q

Cell membrane is selectively permeable to some molecules on either sides. T or F?

181
Q

Passive vs. Active transport

A

Passive - no energy required, along gradient (high to low), simple diffusion

Active - ATP utilised, against gradient (low to high)

182
Q

Bulk vs specific transport

A

Bulk - large molecules

Specific - individual / smaller molecules

183
Q

Endocytosis vs exocytosis

A

Endo - substance enters cell (phago or pino)

Exo - substance leaves cell (secretion or excretion)

184
Q

How do each of these move across cell membrane?

Gas
H2O
Neutral/non-polar solutes (give example)
Polar solutes (give examples)

A

Gas - diffusion
H2O - osmosis
Neutral solutes - diffusion e.g. lipids, steroids
Polar solutes - channels or pumps (e.g. Na+, Cl-, Glucose, Fructose)

185
Q

__________ (polar / non-polar) solutes are water soluble

186
Q

_______ molecules cannot pass through the lipid bilayer and they require a _______ to facilitate their transport

A

Polar, carrier protein

187
Q

Pump vs. channel (4)

A

Pump - made up of protein, requires ATP, active transport from low to high
Channel - made up of protein, no E required, passive transport from high to low

188
Q

Cell membrane is a living structure whereas cell wall is a non-living structure. T or F?

189
Q

Cell wall is a non-living rigid structure of fungi and plants. T or F?

190
Q

Cell wall functions?

A 
shape to cell
protects from mechanical damage
protects from infection
helps in cell-to-cell interaction
barrier to undesirable macromolecules
prevents osmotic bursting
191
Q

Algae have cell wall made of _______

A

cellulose,
galactans,
mannans,
minerals (calcium carbonate)

192
Q

Plants (except algae) have cell wall made of?

A

cellulose,
hemicellulose,
pectins,
proteins

193
Q

Cell wall of young plant cell is called ___________

A

primary wall, growth

194
Q

____________ (primary / secondary) cell wall is capable of growth and ____________ (innermost / outermost)

A

Primary, outermost

195
Q

Primary wall gradually diminishes as cell matures and gives way to ______ formed on the _____ side of the cell

A

secondary wall, inner (towards membrane)

196
Q

Secondary cell wall lies between ____________ and ____________

A

primary cell wall, plasma membrane

197
Q

Secondary cell wall is made up of ____________

A

cellulose

deposits of pectin / suberin / lignin

198
Q

_____ is a layer of cell wall mainly made of calcium pectate which has ______ function

A

middle lamella, flues the different neighbouring cells together

199
Q

Middle lamella is present in almost all cells of plants except ____________

A

epidermal cells

200
Q

When fruits ripen and go soft, it is due to the degeneration of this part ____________

A

middle lamella

201
Q

Cell wall and middle lamellae may be traversed by _________ which connect _______ of neighbouring cells

A

plasmodesmata, cytoplasm

202
Q

Plasmodesmata are present in maximum number in ____________ cells

A

dividing / meristematic

203
Q

Many membranous organelles of cell together considered _______ system because of ________

A

endomembrane system, coordinated functions

204
Q

Endomembrane system includes? (4)

A

ER - endoplasmic reticulum
Golgi complex
Lysosomes
Vacuoles

205
Q

Functions of ________, ________ and _______ are NOT coordinated with endomembrane sys?

A

mitochondria,
chloroplast,
peroxisomes

206
Q

Electron microscope studies of eukaryotic cells finally revealed presence of:

lipids, proteins, ER

207
Q

ER is a network or _________ of tiny _________ structures scattered in cytoplasm

A

reticulum, tubular

208
Q

ER divides the intracellular space into how many compartments? What are they?

A

2,
luminal (inside ER)
extra-luminal (cytoplasm)

209
Q

ER often shows ______ attached to their outer surface

210
Q

RER vs. SER? (2)

A

RER - with ribosomes, protein synthesis

SER - without ribosomes, lipid/fat synthesis

211
Q

RER is site for ___________

SER is major site for __________

A

protein synthesis and secretion,

lipid synthesis

212
Q

SER is extensive and continuous with the outer membrane of the nucleus. T or F?

A

False, RER

213
Q

In plant and animal cells, lipid-like steroidal hormones are synthesized in SER. T or F?

A

False,

in animal cells only - rest is accurate

214
Q

____________ subunit of ribosome attaches to the RER

A

60S, larger

215
Q

Polypeptide produced by mRNA and ribosome goes into ____________ to be folded into a protein

A

lumen of ER

216
Q

When considering the biogenesis, which came first: RER or SER?

A

RER, then evolved into SER

217
Q

Apart from synthesis of lipid and steroids, SER is also responsible for ____________ and ____________

A

detoxification

storing Ca in muscle cells

218
Q

What are the 3 structures/shapes in ER?

A

Cisternae, tubules, vesicles

219
Q

Match the structure to the function:

  1. cisternae
  2. tubules
  3. vesicles

lipid and sterol synthesis, protein synthesis, packing and transport

A
  1. cisternae - protein synthesis
  2. tubules - lipid and sterol synthesis
  3. vesicles - packing and transport
220
Q

_________ first observed densely stained reticular structures near the nucleus. What year?

A

Camillo Golgi (1898)

221
Q

Golgi bodies consist of many flat, disc-shaped sacs or cisternae stacked perpendicular to each other. T or F?

A

False, stacked parallel rest is correct

222
Q

Golgi body sacs diameter: ______

A

0.5 μm to 1.0 μm

223
Q

_____________ are unicisternal whereas _____________ are multicisternal

A

plants, animals

224
Q

A fixed standard number of cisternae are present in Golgi complex. T or F?

A

False, varied

225
Q

What are ‘cis’ and ‘trans’ faces of Golgi?

A

convex / forming face - cis

concave / maturing face - trans

226
Q

Golgi complex cisternae are _________ arranged near the nucleus

A

concentrically

227
Q

Cis and trans faces of the golgi complex are entirely different but interconnected. T or F?

228
Q

Function of golgi apparatus? (4)

A

Modification
Packaging and sorting materials to be delivered intra-cellularly or outside the cell
Formation of glycoproteins and glycolipids
Formation of lysosome

229
Q

Materials to be packaged by golgi are in form of ______ from the ER fuse with ____ face of the apparatus and move towards the _____ face

A

vesicles, cis, trans

230
Q

Why does the golgi apparatus remain in close association with ER?

A

to transfer vesicles from ER

231
Q

Proteins synthesized by ribosomes on ER are modified in the _________ of golgi before release

232
Q

Golgi apparatus is important site of formation of ____ and ____

A

glycoproteins

glycolipids

233
Q

Lysosomes are membrane found ______ structures formed by process of _______

A

vesicular, packaging

234
Q

Lysosomal vesicles are rich in _______

A

almost all types of hydrolytic enzymes active at acidic pH:

hydrolases, lipases, proteases, carbohydrases

235
Q

Enzymes found in lysosomes are capable of digesting ___________

A

macromolecules:

carbs, proteins, lipids and nucleic acids

236
Q

________ is a membrane-bound space found in the cytoplasm

237
Q

Vacuoles contain:

A

water, sap, excretory product and other materials not useful for the cell

238
Q

Vacuole is bound by a single membrane called _________

239
Q

In plant cells, vacuoles can occupy up to _____% of cell volume

240
Q

What is role of tonoplast in plants?

A

Facilitates transport of number of ions/other materials against gradient into the vacuole

241
Q

Why is concentration of ions / other materials higher in vacuole?

A

Tonoplast transports them against gradient

242
Q

In Amoeba _______ vacuole is important for osmoregulation

A

contractile

243
Q

In cells like protists ______ vacuoles are formed by engulfing food particles

244
Q

Mitochondria are easily visible under the microscope. T or F?

A

False, only if specifically stained

245
Q

Number of mitochondria, shape and size per cell is fixed. T or F?

A

False, considerable degree of variability depending on the physiological activity of the cells

246
Q

Shape and size of mitochondrion?

A

Sausage-shaped / cylindrical,
diameter of 0.2-1.0 μm (average 0.5 μm)
length 1.0-4.1 μm

247
Q

There is an inter-membrane space between the outer and inner membrane of mitochondrion. T or F?

248
Q

Each mitochondrion is a double membrane-bound structure with the outer and inner membrane dividing its lumen into two aqueous compartments. T or F?

249
Q

Inner compartment of mitochondrion is filled with _______, a dense homogenous substance.

250
Q

_________ membrane forms the continuous limiting boundary of the organelle.

Outer / inner / both

251
Q

Inner membrane of mitochondria has a number of folding called __________.

These are towards / away (?) from the matrix.

A

crista, towards

252
Q

What do the crista do?

A

Increase surface area

253
Q

The two membranes of mitochondrion share a common set of enzymes produced by the power houses of the cell. T or F?

A

False, own specific enzymes

254
Q

Mitochondria are the site of anaerobic or aerobic respiration?

255
Q

They produce energy in the form of _____, hence they are called ________ of the cell

A

ATP, ‘power houses’

256
Q

Matrix of mitochondria possesses ?

A
  • single circular DNA molecule
  • few RNA molecules
  • ribosomes (70S)
  • components required for protein synthesis
257
Q

Which ribosomes would you find in mitochondria?

258
Q

Mitochondria divide by _________

259
Q

Plastids are found in ________

A

all plant cells and in euglenoides

260
Q

Plastids are small but are easily observed under the microscope. T or F?

A

False, they are large

261
Q

Plastids bear specific pigments, thus imparting color to the plants. T or F?

262
Q

Plastids can be classified into 3 based on ________

What are the 3 types?

A

based on type of pigment

chloroplasts, chromoplasts and leucoplasts

263
Q

Which pigments do each of the plastid types contain?

A

Chloroplasts - chlorophyll (green color) and carotenoid
Chromoplasts - carotenoid - carotene, xanthophyll, etc. (yellow / orange / red color)
Leucoplasts - colorless

264
Q

Carotenoid is present in both chloroplasts and chromoplasts. T or F?

265
Q

What are functions of chloroplasts and leucoplasts?

A

Chloroplasts - trap light energy for photosynthesis

Leucoplasts - store nutrients

266
Q

Types of leucoplasts and what they store?

A

amyloplasts - carbs (starch),
elaioplasts - oils and fats,
aleuroplasts - proteins

267
Q

Majority of chloroplasts are found in ______ cells of the leaves

268
Q

Shapes of chloroplasts?

A 
Lens-shaped
Oval
Spherical
Discoid
Ribbon-like
269
Q

Length and width of chloroplasts?

A

length: 5-10 µm
width: 2-4 µm

270
Q

How many chloroplasts in Chlamydomonas?

A

1 per cell

271
Q

How many chloroplasts in green alga?

A

20-40 per cell

272
Q

Chloroplasts and mitochondria are both double-membraned organelles, however, inner membrane of mitochondria is relatively less permeable. T or F?

A

False, first part is correct, but inner membrane of chloroplast is relatively less permeable

273
Q

Space limited by the inner membrane of the chloroplast is called _______

274
Q

A number of organised flattened membranous sacs called ______ are present in stroma

275
Q

What is special about thylakoid arrangement?

A
  • in stacks called “grana” (like piles of coins)

- flat membranous tubules called stroma lamellae connecting thylakoid of different grana

276
Q

Another name for thylakoids arranged in grana?

A

intergranal thylakoids

277
Q

________ of the thylakoids enclose a space called ________

A

membrane, lumen

278
Q

Stroma of chloroplasts contains ?

A
  • Intergranal thylakoids
  • enzymes for carb and protein synthesis
  • small, double stranded circular DNA molecules
  • ribosomes
279
Q

_________ pigments are present in the thylakoids

A

Chlorophyll

280
Q

Ribosomes of chloroplasts are 80S or 70S?
Ribosomes of the cytoplasm?
Which are smaller?

A

chloroplasts - 70S, smaller

cytoplasm - 80S

281
Q

Ribosome were first observed under the electron microscope as ________ by __________ in the year __________

A

dense particles,
George Palade
1953

282
Q

Ribosomes are ___________ structures, composed of ________ and _______.

A

granular, RNA and proteins

283
Q

Mitochondria, ribosomes and chloroplasts are double-membraned structures. T or false?

A

False, ribosome has NO membrane

284
Q

Eukaryotic ribosomes are ____S and prokaryotic are ____S

A

eukaryotic - 80S

prokaryotic - 70S

285
Q

What are the subunits of 70S? 80S?

A

70S: 50S and 30S
80S: 60S and 40S

286
Q

What does S (wrt ribosomes) stand for?

A

Svedberg’s Unit, sedimentation coefficient, indirect measure of density and size

287
Q

What are cytoskeleton?

A
  • elaborate network of filamentous proteinaceous structures
  • consist of microtubules, microfilaments and intermediate filaments
  • present in cytoplasm
288
Q

What functions are cytoskeleton involved in?

A
  • mechanical support
  • motility
  • maintenance of cell shape
289
Q

______ and ______ are hair-like outgrowths of the cell membrane

A

cilia and flagella

290
Q

Cilia vs. flagella structure?

A

cilia - small, work-like oars

flagella - longer

291
Q

Cilia cause movement of ________ where flagella are responsible for ______ movement

A

cilia - cell or surrounding fluid

flagella - cell

292
Q

Prokaryotic bacteria flagella are structurally similar to eukaryotic flagella. T or F?

A

False, structurally different

293
Q

Cilia and flagella are covered with __________ and have a core called _______

A

plasma membrane

core - axoneme

294
Q

Axoneme of cilia/flagella possesses a number of ________ running parallel to _______

A

microtubules, long axis

295
Q

Axoneme has ____ doublets of radially arranged peripheral microtubules and a pair of _______ located microtubules.

This arrangement is called ________

A

nine, centrally

9+2 array

296
Q

Central tubules of axoneme are connected via _______ whereas peripheral doublets are interconnected by ______

A

bridges, linkers

297
Q

Central tubules are enclosed by a ________

A

central sheath

298
Q

Central sheath of central tubules is connected to ___________ by radial spoke

A

one of the tubules of each peripheral doublet

299
Q

How many radial spokes in an axoneme?

A

9 (since 9 doublets)

300
Q

Cilium and flagellum emerge from ________-like structure called basal bodies

A

centriole-like

301
Q

__________ is an organelle usually containing 2 cylindrical structures called _______

A

Centrosome, centrioles

302
Q

Centrioles like ______ to each other and each has an organisation like ________

A

perpendicular, cartwheel

303
Q

Centrioles are surrounded by ___________

A

amorphous pericentriolar materials

304
Q

Centrioles are made up of nine evenly spaced peripheral fibrils of ________. Each fibril is a ______, with adjacent ones linked.

A

tubular protein, triplet

305
Q

The ______ part of the ______ region of the centriole is also proteinaceous and called the hub. It is connected with peripheral fibril triplets by radial spokes made of _______

A

central, proximal, protein

306
Q

Centrioles form the basal body of ______ or _______

A

cilia or flagella

307
Q

Centrioles form the basal body of _____ that give rise to spindle apparatus during cell division

A

spindle fibres

308
Q

Spindle fibers give rise to the spindle apparatus during cell division in plant and animal cells. T or F?

A

False, in animal cells

309
Q

Nucleus was first described by Robert Brown, but it was stained by basic dyes and given the name _________ by ________

A

chromatin, Flemming

310
Q

Interphase nucleus is the nucleus when it is _________

A

not dividing

311
Q

Interphase nucleus has highly extended and elaborate _____________ called chromatin, ______ matrix and one or more spherical bodies called _______

A

nucleoprotein fibres, nuclear, nucleoli

312
Q

Nuclear envelope forms a barrier between _______ and ______

A

materials inside the nucleus and cytoplasm

313
Q

Nuclear envelope consists of ________ membranes with a space between called _________

A

parallel, perinuclear space

314
Q

Size of perinuclear space is ________

A

10 to 50 nm

315
Q

Outer membrane of nucleus usually remains continuous with ________ and also bears ________

A

ER, ribosomes

316
Q

The nuclear envelope is interrupted at a number of places by _______ formed by the fusion of ________

A

minute pores, fusion of its two membranes

317
Q

Nuclear pores are the passages through which movement of _______ takes place in ____ direction(s) between nucleus and cytoplasm

A

RNA and proteins, both directions

318
Q

Some mature cells lack nucleus like erythrocytes of mammals and sieve tube cells of plants. T or F?

319
Q

Nuclear matrix is aka ________

A

nucleoplasm

320
Q

Nucleoplsam contains ____ and _____

A

nucleoli (special structures) and chromatin

321
Q

Content of nucleolus is discontinuous with rest of nucleoplasm because it has a membrane separating the contents of nucleolus from matrix. T or F?

A

False, continuous and no membrane

322
Q

Nucleolus is a site for __________ synthesis

A

active ribosomal RNA synthesis

323
Q

__________ are present in cells actively carrying out protein synthesis

A

Larger and more numerous nucleoli

324
Q

During different stages of cell divisions, cells show structured ___________ instead of nucleus

A

chromosomes

325
Q

What do chromatin contain?

A

DNA,
basic proteins called histones
non-histone proteins
and also RNA

326
Q

A single human cell has approximately ____ meter long thread of DNA among its _______ chromosoms

A

2m, 46 chromosomes

327
Q

Chromosomes are visible only in dividing cells. T or F?

328
Q

What are centromere and kinetochores?

A

centromere - primary constriction in chromosome

kinetochores - disc-shaped structures on sides of centromere

329
Q

__________ holds two chromatids of chromosomes.

Kinetochore or centromere?

A

Centromere

330
Q

Chromosomes can be classified into 4 types based on ________. They are?

A

position of centromere;

metacentric - two equal arms
sub-metacentric - slightly away from middle (one shorter, one longer)
acrocentric - close to its end (one extremely short and one very long)
telocentric - terminal

331
Q

Sometimes a few chromosomes have non-staining secondary constrictions at a constant location, giving the appearance of a fragment called ________

332
Q

_______ are membrane-bound minute vesicles that contain various enzymes

A

Microbodies

333
Q

Microbodies are present only in animal cells. T or F?

A

False, plant and animal

334
Q

Typical eukaryotic cell consists of cell membrane, nucleus and cytoplasm. T or F?

335
Q

Nucleus controls activity of organelles and plays major role in ________

336
Q

ER helps in transport of substances and synthesis of _______

A

proteins, lipoproteins and glycogen

337
Q

Mitochondria help in ___________ and generation of _______

A

oxidative phosphorylation and generation of adenosine triphosphate (ATP)

Biology (NCERT) - Class XI (23 decks)

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