Cell: Unit of Life Flashcards
(110 cards)
1
Q
Define Cytology
A
Study of cell and cellular structure
2
Q
What is the difference between unicellular and multicellular organisms?
A
Unicellular: Single-celled, Independent existence, can perform all the essential functions of life.
Multicellular: Component of many cells
3
Q
Give an example of unicellular organisms
A
Bacteria or Amoeba
4
Q
Give an example of multicellular organisms
A
Humans, buffalo, etc.
5
Q
Who discovered the cell?
A
Robert Hooke
6
Q
What type of cell did Robert Hooke discover?
A
He saw a cell wall of a dead cell and not the cell.
7
Q
Did Robert Hooke observe a living cell?
A
No
8
Q
Who first saw and described the living cell?
A
Anton von Leeuwenhoek
9
Q
Who discovered the nucleus?
A
Robert Brown
10
Q
Who were the three scientists who formulated the cell theory?
A
Matthias Schleiden, Theodore Schwann and Rudolf Virchow
11
Q
Whats was the cell theory?
A
- All living organisms are composed of cells and their products
- Cell is the structural unit of life.
- New cells arise from preexisting cells.
12
Q
Which statement described by Rudolf Virchow explained the formation of new cells?
A
Omnis cellula-e-cellula
13
Q
Name the smallest cell
A
Mycoplasma
14
Q
What are the features of mycoplasma?
A
Mycoplasma can survive without O2 and without a cell wall.
15
Q
What is the largest cell?
A
Ostrich’s egg
16
Q
Name the smallest cell in the Human body
A
RBC
17
Q
Name the largest cell in the human body
A
Ovum
18
Q
Name the longest cell in human body
A
Nerve cell
19
Q
Difference between Prokaryotic and Eukaryotic cell, INCLUDE EXAMPLES
A
Prokaryotic Cell 1. Lacks membrane-bound nucleus. 2. Lack membrane-bound cell organelle Eg: Cyanobacteria/BGA, Bacteria and Mycoplasma Eukaryotic Cell 1. Have a membrane-bound nucleus. Have a membrane-bound organelle Eg: ER, Mitochondria, Golgi Bodies, Lysosomes.
20
Q
Bacteria are of what types and what are their shapes?
A
Bacillus (Rod-shaped)
Coccus ( spherical shaped)
Vibrio (comma-shaped)
Spirillum (Spiral shaped)
21
Q
What is the cell envelope made out of? list in order, first being the outer shell and last being the inner shell.
A
- Glycocalyx
- Cell Wall
- Plasma Membrane
22
Q
What are the different ways glycocalyx can be around the cell?
A
Glycocalyx can be LOOSELY packed —> SLIME LAYER
Glycocalyx can be TIGHTLY packed —–> CAPSULE
23
Q
What is a dense membrane-bound structure?
A
Nucleus
24
Q
What are chromosomes?
A
they are genetic material (DNA) inside the nucleus
25
Which types of cells have membrane-bound nuclei?
Eukaryotic
26
A semi-fluid matrix occupying the volume of cell
Cytoplasm
27
Which types of cells lack membrane-bound nuclei?
Prokaryotic
28
Which organelle is non-membrane-bound and is in both prokaryotic as well as eukaryotic cells?
Ribosomes
29
Name all the non-membrane-bound organelles in animal cells.
Ribosomes and centrosome
30
Which organelle helps in cell division
centrosome
31
What is the length of Mycoplasma
0.3 micrometer (µm)
32
What are the different types of shapes of cells?
Disc-like, polygonal, columnar, cuboid, thread-like, or even irregular.
33
What is an example of mycoplasma?
PPLO
| Pleuro Pneumonia like organism
34
What is the cell wall made of?
Peptidoglycan
35
What makes up the plasma membrane?
phospholipid and protiens
36
Some basic features of the prokaryotic cells...
1. cytoplasm, cell organelles, and inclusion bodies
| 2. Naked genetic material, genomic DNA (single-stranded)
37
Describe the features in the cell wall of prokaryotic cells
1. It determines the shape of the cell
2. Provides strong structural support to the cell
3. Prevents bacteria from collapsing or bursting
38
Describe the features in the plasma membrane
1. semi-permeable membrane
| 2. structure similar to eukaryotes (phospholipids and proteins)
39
"Many bacteria have small circular DNA outside the genomic DNA. These smaller DNA are called _________"
Plasmid
40
"These Plasmids contain___________ characteristics to bacteria" give an example
Phenotypic
| Eg: they give resistance to antibiotics to bacteria
41
What is the essential folding in the prokaryotic cells called?
Mesosomes
42
how are mesosomes formed?
They are formed by the extensions in the plasma membrane into the cell. They are formed in the form of vesicles, tubules, and lamella.
43
What are the functions of mesosomes?
Helps in
1. cell wall formation
2. DNA replication and distribution to daughter cells
3. In respiration
4. secretion
5. Increase the surface area of the plasma membrane
6. Increase in enzymatic content.
44
What are chromatophores?
They are membranous extensions in the cytoplasm
45
What do chromatophores have?
Chromatophores contain pigments
| Eg: Cyanobacteria
46
What is a flagellum?
They are filamentous extensions from the cell walls.
47
Where are flagella present?
They are present in motile cells
48
Name the parts in Flagella
Filament, Hook and basal body
49
Bacteria which take up the gram stain are called _________
Gram-positive
50
Bacteria which don't take up the gram stain are called _________
Gram-negative
51
Describe the structure of Pilli
Pilli is an elongated structure
52
Describe the structure of fimbriae
Fimbriae are small bristle-like fibers
53
What function did pilli and fimbriae perform?
Attachment of bacteria to rocks in streams and also to host tissues
54
Ribosomes are associated with _________ of the cell
plasma membrane
55
Ribosomes subunits in a prokaryotic cell are
50s and 30s
56
Sit of protein synthesis in prokaryotic cell ______
70s
57
Explain the formation of polysome
Several ribosomes attach to mRNA and form polysome
58
€what do the proteins of polysome do?
Ribosomes of a polysome translate the mRNA into protein
59
What is the function of inclusion bodies in a prokaryotic cell?
For storage of reserver material in prokaryotic cells
60
Explain the structure if inclusion bodies
inclusion bodies are not membrane-bound and lie free in the cytoplasm
61
Give examples of inclusion bodies
Phosphate granules, cyanophycean granules, and glycogen granules
62
In which organisms are gas vacuoles found
blue-green and purple and green photosynthetic bacteria
63
State the characteristics of a eukaryotic cell
1. presence of membrane-bound cell organelles
2. organized nucleus with a nuclear membrane
3. Genetic material is organized into chromosomes
64
The cell membrane is mainly composed of ____ and ____
Phospholipid and protein
65
Explain the structure of lipids
Lipids on top contain a hydrophilic polar head and a hydrophobic tail
66
What does hydrophobic and hydrophilic mean
Hydrophobic means afraid of the water, while hydrophilic means the opposite
67
How are lipids arranged within the membrane
The lipids are arranged within the membrane within the polar heads towards the outer sides and hydrophobic tails towards the inner part.
68
Why were they arranged in such a manner?
So the hydrophobic tails are protected from the saturated environment
69
What are all the components of the cell membrane
Protein, sugar, cholesterol, carbohydrates, and phospholipids
70
What is the ratio of phospholipid and proteins in erythrocyte (RBC) in human beings
52% of protein
| 40% lipids
71
who proposed the fluid mosaic model?
Singer and Nicolson
72
What is the fluid nature of the Plasma membrane important for?
cell growth, intercellular junction, endocytosis, cell division, etc
73
What is the most important function of the plasma membrane?
transportation
74
Movement of water by diffusion is called ______________
osmosis
75
What are the different types of transportation which occur through the plasma membrane
Active and passive
76
explain passive transport
Transportation occurs without the requirement of energy, like through simple diffusion. So the material goes from lower concentration to higher concentration
77
Explain active transport
A few molecules are transported accross the membrane against the concentration gradient, i.e., from lower concentration to higher concentration. Such transport requires energy, so ATP is utilized. this is known as active transport.
78
What does a cell wall do?
It gives shape to the cell
Protects the cell
Helps in cell to cell interaction
79
What is the cell wall of plants made of?
Cellulose, protein, pectin
80
What is the cell wall of fungi made of?
Chitin
81
What is the cell wall of algae made of?
Cellulose, galactan, mannan, CaCo3
82
What are the layers of cell wall
Middle lamellae, Primary wall, secondary wall
83
Explain middle lamellae?
Outermost
calcium pectate
holds the neighboring cells
84
Explain the primary wall and its function?
present in young cell diminishes as the cell grows
| capable of growth
85
explain stuff about secondary wall
innermost
lignified (wall impermeable) and waxy
PRESENT IN DEAD CELLS
86
Name double membrane-bound organelles
Mitochondria, Chloroplast/plastids
87
Name non membrane bound organelles
Ribosomes and centrioles
88
Name all the functions of mitochondria
```
Site of aerobic respiration
energy formation = "powerhouse of the cell"
single circular DNA
few RNA molecules
Ribosomes (70s) = protein synthesis
Semi autonomous organelle
Divides on its own
```
89
Draw the diagram of mitochondria
https://www.shaalaa.com/images/_4:50ce067069134e4e853262ae93cf7f12.png
90
Where are PLastids found?
Found in all plant cells and euglenoids
91
What are the 3 types of plastids?
Chloroplast
Chromoplast
Leucoplast
92
Discuss chloroplast
contains chlorophyll and carotenoids, helps in trapping the light energy for photosynthesis
93
Discuss chromoplast
Contains fat soluble
| gives colors to flowers
94
Leucoplasts further divides into ________,________, and ______________
Amyloplasts
Elaioplsats
Aleuroplasts
95
What do Amyloplasts store?
Carbohydrates
96
What do Eliaoplasts store?
Oils and fats
97
What do aleuroplasts store?
Proteins
98
draw the sectional view of chloroplast
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.entrancei.com%2Fquestion-answer%2Fdraw-sectional-view-of-chloroplast-32230&psig=AOvVaw1Rg-y02dVWLFLBRid8OXkz&ust=1632148275868000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCNj6maSgi_MCFQAAAAAdAAAAABAD
99
The space limited by the inner membrane of the chloroplast is called the ___________
stroma
100
a number of organized flattened membranous sacs are called __________
thylakoids
101
Discuss grana
Grana is the stake of thylakoid
| contains chlorophyll
102
Discuss stroma
Limited by the inner membrane
| Contains enzymes synthetic of protein and carbohydrate
103
What is thylakoid?
Thylakoid are flattened structure
104
state some facts of chloroplast
contains small, ds circular DNA, ribosomes (70s)
| semi-autonomous organelle
105
What is the endoplasmic reticulum?
Network or tubular structures scattered in the cytoplasm
106
What are the two types of ER?
Smooth ER and Rough ER
107
Differentiate between smooth ER and rough ER (3 points each)
```
SMOOTH ER
- Absence of ribosomes
- synthesis of lipids
-Animal cell = steroid, hormones synthesis
ROUGH ER
- Bears ribosomes
- Sites for proteins synthesis
- Proteins synthesis + secretion
```
108
who discovered the Golgi apparatus?
Camillo Golgi
109
Describe the structure of Golgi bodies?
Many flat, disc-shaped sacs or cisternae staked parallely
110
Explain the whole process that occurs in Golgi apparatus
look in notes
