Lesson 1 Biology Flashcards
(119 cards)
1
Q
What is the basic unit of life?
A
Cell
2
Q
True or False: All living organisms are made up of cells.
A
True
3
Q
What structure controls the movement of substances in and out of a cell?
A
Cell membrane
4
Q
Fill in the blank: The jelly-like substance inside a cell is called __________.
A
Cytoplasm
5
Q
Which organelle is known as the powerhouse of the cell?
A
Mitochondria
6
Q
What is the function of ribosomes?
A
Protein synthesis
7
Q
Multiple Choice: Which of the following is NOT a part of the cell theory? A) All living things are composed of cells, B) Cells arise from pre-existing cells, C) Cells can spontaneously generate, D) The cell is the basic unit of life.
A
C) Cells can spontaneously generate
8
Q
What is the role of the nucleus in a cell?
A
It stores genetic information and controls cell activities.
9
Q
True or False: Prokaryotic cells have a nucleus.
A
False
10
Q
Fill in the blank: The structure that gives plant cells their shape is called the __________.
A
Cell wall
11
Q
What are the two main types of cells?
A
Prokaryotic and Eukaryotic
12
Q
Multiple Choice: Which organelle is responsible for photosynthesis? A) Mitochondria, B) Chloroplast, C) Golgi apparatus, D) Endoplasmic reticulum.
A
B) Chloroplast
13
Q
What is the primary function of the endoplasmic reticulum?
A
Synthesis and transport of proteins and lipids.
14
Q
True or False: Lysosomes are involved in digestion within the cell.
A
True
15
Q
Fill in the blank: The __________ is responsible for packaging and distributing proteins.
A
Golgi apparatus
16
Q
What is the role of the cytoskeleton?
A
It provides structure and support to the cell.
17
Q
Multiple Choice: Which type of cell lacks membrane-bound organelles? A) Eukaryotic, B) Prokaryotic, C) Both A and B, D) Neither A nor B.
A
B) Prokaryotic
18
Q
What is apoptosis?
A
Programmed cell death.
19
Q
True or False: The plasma membrane is selectively permeable.
A
True
20
Q
Fill in the blank: The __________ is a network of protein filaments that helps the cell maintain its shape.
A
Cytoskeleton
21
Q
What is the function of the nucleolus?
A
Ribosome production.
22
Q
Multiple Choice: Which structure is found in plant cells but not in animal cells? A) Cell membrane, B) Mitochondria, C) Chloroplast, D) Nucleus.
A
C) Chloroplast
23
Q
What is the main component of the cell membrane?
A
Phospholipids
24
Q
True or False: All cells have a cell wall.
A
False
25
Fill in the blank: The __________ is involved in the modification and sorting of proteins.
Golgi apparatus
26
What is the primary function of vacuoles in plant cells?
Storage of substances.
27
What is the basic unit of life?
The cell.
28
What are ribosomes?
The sites of protein synthesis.
29
What is the function of the Golgi apparatus?
The delivery system of the cell.
30
What does the endoplasmic reticulum (ER) do?
It forms the supporting framework of the cell and serves as a pathway for the distribution of materials.
31
What are mitochondria known as?
The powerhouses of the cell.
32
What is stored in mitochondria?
ATP (adenosine triphosphate) is stored in the form of an energy-rich compound.
33
What is cytoplasm?
A semi-liquid substance that occupies most of the cell.
34
What are plastids?
Organelles found only in plant cells.
35
What is the role of lysosomes?
They contain enzymes for digestion within the cell.
36
What is the function of the cell wall?
It is freely permeable, allowing substances in solution to enter and leave the cell.
37
What does the cell membrane do?
It allows the cell to maintain its internal environment.
38
39
What are complexes in plants more specifically known as?
Dictyosomes. They usually contain smaller and more scattered groups of cisternae and vesicles.
40
What are the functions of golgi complexes and dictyosomes?
Both are concerned with the secretions of the cell including enzymes, hormones, etc., and their packaging and transport to different sites within the cell.
41
What are lysosomes?
Small vesicles of different shapes containing digestive enzymes.
42
What do lysosomal enzymes do?
They destroy and digest foreign substances around them.
43
How do lysosomes help during unfavorable conditions?
They digest the stored food when food is unavailable to the cell.
44
Why are lysosomes referred to as 'suicide bags'?
Many damaged cells are rapidly destroyed or dissolved by their own lysosomes.
45
What is a centrosome?
A structure found only in animal cells that contains two centrioles.
46
What develops from the centrosome during cell division?
Spindle fibres develop during both mitosis and meiosis.
47
What are centrioles?
Short bundles of microfilaments arranged at right angles to each other.
48
Where are plastids found?
Only in plant cells.
49
What are the three types of plastids?
Leucoplasts, chromoplasts, and chloroplasts.
50
What are leucoplasts?
Colourless plastids that store starch.
51
What are chromoplasts?
Colored plastids that are mostly present in petals of flowers and fruits.
52
What pigments are associated with chromoplasts?
Xanthophyll (yellow) and carotene (orange-red).
53
What are chloroplasts?
Green-coloured plastids that contain chlorophyll.
54
What is the primary function of chloroplasts?
To trap solar energy and absorb carbon dioxide for the manufacture of starch and sugar during photosynthesis.
55
What happens to chlorophyll during the ripening of tomatoes?
Chlorophyll degenerates and the masked red (carotene) takes over.
56
What are granules in the cytoplasm?
Small particles believed to contain food materials such as starch, glycogen, and fats.
57
What are vacuoles?
Clear spaces in the cytoplasm filled with water and various substances in solution.
58
How do vacuoles differ between plant and animal cells?
Plant cells usually have large vacuoles filled with cell sap, while animal cells have smaller vacuoles.
59
What is the nucleus?
The most important part of the cell that regulates and coordinates various life processes.
60
What role does the nucleus play in cell division?
It plays an important part in cell division.
61
What does the nucleus contain that determines heredity?
Factors (genes) that determine heredity.
62
What is the nucleus?
The nucleus is a small spherical mass located somewhat in the center of the cytoplasm.
63
What fills the nuclear membrane?
The nuclear membrane is filled with a relatively dense nucleoplasm.
64
What are chromatin fibres?
Chromatin fibres are thread-like structures found in the nucleoplasm.
65
What happens to chromatin fibres during cell division?
During cell division, chromatin fibres become thick and ribbon-like, forming chromosomes.
66
What are prokaryotic cells?
Prokaryotic cells are cells in which the nuclear membrane is absent, such as bacteria.
67
What is the nucleoid?
The nucleoid is the central region of the cytoplasm where chromatin fibres occur freely in prokaryotic cells.
68
What are eukaryotic cells?
Eukaryotic cells are cells with a double nuclear membrane, including all organisms other than bacteria.
69
What is a nucleolus?
The nucleolus is a structure within the nucleus that participates in the protein synthesis of ribosomes.
70
How many chromosomes do human body cells have?
Every human body cell has 46 chromosomes, which are 23 pairs.
71
What is the relationship between chromosomes and genetic characters?
Chromosomes carry genetic characters from parents to offspring through the union of the egg and sperm.
72
What are genes made of?
Genes are made of a complex chemical substance called DNA (deoxyribonucleic acid).
73
What determines the characteristics of a species?
It is the genes, not the number of chromosomes, that determine the characteristics of a species.
74
What is DNA fingerprinting?
DNA fingerprinting is a technique that helps in identifying individuals based on variations in non-functional DNA.
75
How does DNA fingerprinting help in parentage testing?
DNA patterns can ascertain the identity of a person and testify the parentage of an individual.
76
What is the cell wall?
The outermost part in plant cells, non-living, rigid, and mainly composed of cellulose.
## Footnote
Provides protection and gives rigidity and shape to the plant cell.
77
What is the plasma membrane?
The outermost part in animal cells, a very thin, flexible, living membrane that is semi-permeable and made up of lipoproteins.
## Footnote
Separates contents of cell from its surroundings and regulates the entry of certain solutes and ions.
78
What is cytoplasm?
The mixture of water, soluble inorganic and organic compounds, and various organelles inside the plasma membrane excluding the nucleus.
## Footnote
All metabolic activities occur in it.
79
What is the endoplasmic reticulum (ER)?
An irregular network of single-membraned tubules that is continuous with the plasma membrane and nuclear membrane, may be smooth or rough.
## Footnote
Synthesis and transport of proteins and fats.
80
What are mitochondria?
Sausage-shaped, double-walled organelles with inner folds (cristae) that have their own DNA and ribosomes.
## Footnote
Release energy from pyruvic acid in the form of ATP and are the site of cellular aerobic respiration.
81
What is the Golgi apparatus?
Stacks of flattened membrane sacs consisting of tubules, vesicles, and vacuoles.
## Footnote
Synthesis and secretion of enzymes, hormones, and formation of acrosome of sperm (only in animals).
82
What are ribosomes?
Small granules either scattered in the cytoplasm or attached to the endoplasmic reticulum, composed mainly of RNA.
## Footnote
Protein synthesis.
83
What are lysosomes?
Membranous sacs budded off from Golgi bodies, containing various enzymes.
## Footnote
Intracellular digestion, destroying foreign substances, and rapidly destroying organelles in old or injured cells.
84
What is a centrosome?
A region surrounding the centrioles, located near the nucleus. Contains one or two centrioles, which are surrounded by radiating microtubules to form a 'star' (aster) during cell division.
85
What are plastids?
Several kinds, most commonly chloroplasts containing the green pigment chlorophyll. Double membraned, proteinaceous matrix, contain DNA. Disc-like structures called thylakoids contain chlorophyll.
86
What is the nucleus?
Largest cell organelle. Mostly spherical and dense. Nuclear membrane with pores to allow substances to enter and leave. Contains a network of thread-like structures called chromatin fibres which contain DNA.
87
What are chromatin fibres?
The network in resting stage of the nucleus condenses into chromosomes during cell division. Made up of DNA threads.
88
What are vacuoles?
Clear spaces with water or other substances in solution. Plant cells have larger vacuoles, while animal cells have smaller ones.
89
What are granules?
Small particles, crystals or droplets. Chloroplasts (green) trap solar energy for photosynthesis and contain the pigment chlorophyll.
90
What is the function of the nucleolus?
Produces ribosomes. Participates in protein synthesis by forming and storing RNA. Dictates ribosomes to synthesize proteins.
91
What is the role of chromosomes?
Chromosomes carry hereditary information or the genes from parents to offspring.
92
What do vacuoles store?
Store water and other substances like food and waste products. Give turgidity to the plant cells by pressing against the cell wall. Contain pigments like anthocyanins, etc.
93
What do granules store?
Store starch (in plant cells), glycogen (in animal cells) and fat-containing globules which serve as food for the cell.
94
What structures are common in both plant and animal cells?
Both contain the plasma membrane, cytoplasm, nucleus, endoplasmic reticulum, golgi apparatus, mitochondria, and ribosomes.
95
What is a key difference in cell walls between plant and animal cells?
Plant cells have a definite cell wall made up of cellulose, while animal cells do not have a cell wall.
96
How do vacuoles differ between plant and animal cells?
Plant cells have prominent vacuoles, usually one or more, while animal cells have small and temporary vacuoles.
97
What are plastids and which type of cells contain them?
Plastids are usually present in plant cells and are not found in animal cells.
98
How does the size of plant and animal cells typically compare?
Plant cells are usually larger with distinct outlines, while animal cells are usually smaller with less distinct boundaries.
99
What is protoplasm?
Protoplasm is the living substance in an organism, contained within cells.
100
What is the chemical composition of protoplasm?
Protoplasm includes elements such as carbon, hydrogen, oxygen, nitrogen, sulfur, iron, and phosphorus in the form of compounds like water, proteins, carbohydrates, fats, and mineral salts.
101
Why is it difficult to analyze protoplasm chemically?
Protoplasm ceases to be protoplasm as soon as it is removed from the organism.
102
Cell : The Unit of Iife
103
Examples : Bacteria
Blue green algae (Cyanobacteria)
104
Examples : Euglena
Amoeba and all plants and animals
105
4. No other cell organelles
106
chloroplasts
etc.
107
4. Several organelles like mitochondria
endoplasmic reticulum
108
3. Small ribosomes
109
3.Larger ribosomes
110
(DNA)
111
12. A single length of only deoxyribonucleic acid
112
2. Several lengths of genetic material (chromosomes) containing
113
DNA wound around certain proteins
114
Nucleus is not well defined (nucleoid)
115
Well defined nucleus with a nuclear membrane
116
PROKARYOTIC CELL
117
Table 2.3 Differences between Prokaryotic
118
and Eukaryotic cells
119
EUKARYTOIC CELL
