Living Organism | Jamb Biology

Jamb(UTME) summaries/points on characteristics of living organisms; Cell structure and functions of cell components

Characteristics of Living Organisms

1. Living organisms exhibit movement, either internally or externally.
2. They perform respiration to produce energy.
3. They exhibit sensitivity, responding to stimuli.
4. They undergo growth, increasing in size or number of cells.
5. Living organisms reproduce to ensure the continuation of their species.
6. They excrete waste products generated by metabolism.
7. They require nutrition for energy and building materials.
8. They exhibit metabolism, involving anabolic (building) and catabolic (breaking down) processes.
9. Living organisms maintain homeostasis, keeping their internal environment stable.
10. They adapt over generations to environmental changes.
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Differences Between Living and Non-Living Things

11. Living things are made of cells, while non-living things lack cellular structure.
12. Living things grow internally; non-living things may only accumulate matter externally.
13. Living organisms can reproduce; non-living things cannot.
14. Living things respond to stimuli; non-living things do not.
15. Energy production occurs in living organisms; non-living things do not utilize energy.
16. Living organisms have metabolic processes; non-living things are chemically inactive.
17. Living things can adapt and evolve over time; non-living things remain static.
18. Living organisms excrete waste; non-living things do not.
19. Living things require nutrients; non-living things do not.
20. Living organisms maintain homeostasis; non-living things cannot regulate themselves.
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Structures of Plant and Animal Cells

21. Plant cells have a rigid cell wall; animal cells do not.
22. Animal cells have a flexible cell membrane.
23. Plant cells contain chloroplasts for photosynthesis; animal cells do not.
24. Plant cells have a large, central vacuole; animal cells have smaller or no vacuoles.
25. Animal cells have centrioles, which are absent in most plant cells.
26. Plant cells are typically rectangular, while animal cells are rounded.
27. Both plant and animal cells contain a nucleus that controls activities.
28. Both have mitochondria, the powerhouse of the cell.
29. Cytoplasm is present in both types for chemical reactions.
30. Both types have ribosomes for protein synthesis.
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Functions of Cell Components

31. The cell wall in plant cells provides structure and protection.
32. The cell membrane controls the entry and exit of substances.
33. The nucleus stores genetic material and regulates cell functions.
34. The cytoplasm is the site of biochemical reactions.
35. The mitochondria produce energy through cellular respiration.
36. Ribosomes synthesize proteins needed for cell functions.
37. The rough endoplasmic reticulum (RER) transports proteins synthesized by ribosomes.
38. The smooth ER synthesizes lipids and detoxifies chemicals.
39. The Golgi apparatus packages and modifies proteins for secretion.
40. Lysosomes digest cellular waste and unwanted materials.
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Cell Structure and Functions

41. Chloroplasts convert sunlight into chemical energy in plant cells.
42. The nucleolus inside the nucleus produces ribosomes.
43. Vacuoles in plant cells store water and nutrients and maintain pressure.
44. Centrioles help organize cell division in animal cells.
45. Cytoskeleton provides structure and facilitates movement in cells.
46. Peroxisomes break down fatty acids and detoxify harmful substances.
47. Plasmodesmata in plant cells allow communication between cells.
48. The nuclear envelope protects the nucleus and regulates material exchange.
49. Flagella and cilia enable movement in some animal and protist cells.
50. Chromosomes carry genetic information for inheritance.
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Energy Production in Cells

51. Mitochondria generate ATP through the oxidation of glucose.
52. Chloroplasts in plants perform photosynthesis to produce glucose.
53. The electron transport chain in mitochondria drives ATP synthesis.
54. Glycolysis occurs in the cytoplasm to break glucose into pyruvate.
55. The Krebs cycle in mitochondria generates high-energy molecules like NADH.
56. Plant cells use the Calvin cycle in chloroplasts to produce sugars.
57. Cellular respiration is vital for energy in animal and plant cells.
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Additional Functions of Cell Components

58. Cell membranes use proteins for active and passive transport.
59. The cytoskeleton supports intracellular transport.
60. Golgi vesicles transport proteins and lipids within the cell.
61. Lysosomes recycle cellular components through autophagy.
62. Endoplasmic reticulum helps in membrane protein synthesis.
63. Ribosomes translate mRNA into proteins.
64. Vacuoles regulate osmotic balance in plant cells.
65. Plasma membrane receptors detect environmental signals.
66. Nuclear pores allow selective material exchange with the cytoplasm.
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Differences in Plant and Animal Cells

67. Plant cells rely on chloroplasts for energy; animal cells rely on mitochondria alone.
68. The cell wall provides rigidity in plants; animal cells are flexible due to a lack of a wall.
69. Plant cells store carbohydrates as starch; animal cells store it as glycogen.
70. Animal cells have lysosomes for digestion; these are less common in plant cells.
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Cellular Processes

71. Photosynthesis in chloroplasts uses light to make glucose.
72. Cellular respiration in mitochondria breaks down glucose for energy.
73. Proteins made in the rough ER are transported by vesicles to the Golgi apparatus.
74. The smooth ER detoxifies substances in liver cells.
75. ATP is synthesized in mitochondria during oxidative phosphorylation.
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Application of Cellular Functions

76. Photosynthesis sustains life on Earth by producing oxygen and glucose.
77. Cellular respiration powers cell activities in plants and animals.
78. The Golgi apparatus ensures proper protein transport in cells.
79. Lysosomes prevent cellular damage by breaking down waste.
80. Ribosomes drive protein synthesis, essential for growth and repair.
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Unique Properties of Cells

81. Plant cells can store toxins in vacuoles as a defense mechanism.
82. Animal cells use centrioles to align chromosomes during division.
83. Plant cell walls protect against mechanical stress.
84. The nuclear envelope maintains genomic integrity.
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Transport and Communication

85. Plant cells communicate via plasmodesmata.
86. Animal cells use gap junctions for direct communication.
87. Active transport moves molecules against their concentration gradient.
88. Passive transport allows diffusion of small molecules.
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Advanced Concepts

89. Plant cells use turgor pressure for structural support.
90. Animal cells use actin filaments in the cytoskeleton for movement.
91. Protein folding occurs in the rough ER.
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Comparisons of Organelles

92. Both plant and animal cells contain nucleic acids for genetic information.
93. The mitochondria and chloroplasts both produce energy but in different forms.
94. Ribosomes are universal for protein synthesis in all cells.
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Practical Relevance

95. Understanding cells aids in genetic engineering and medicine.
96. Cell research is key to cancer therapies and regenerative medicine.
97. Chloroplast studies enhance agricultural productivity.
98. Mitochondrial function is vital for metabolic health.
99. Cellular communication research improves understanding of diseases.
100. Cell biology lays the foundation for advances in biotechnology and healthcare.
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Jamb(UTME) summaries/points Level of organization; Cell; Tissue; Organ; Systems; Organisms

Levels of Organization in Biology

1. The levels of organization in biology describe the hierarchy of structures in living organisms.
2. The sequence is cell → tissue → organ → system → organism.
3. Each level is more complex than the previous one.
4. Cells are the basic structural and functional units of life.
5. Tissues are groups of similar cells that perform a specific function.
6. Organs are structures composed of different tissues working together.
7. Organ systems are groups of organs that work together to carry out complex functions.
8. The organism is the complete living entity capable of independent life.
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Cell (Euglena and Paramecium)

Euglena

9. Euglena is a unicellular organism that exhibits characteristics of both plants and animals.
10. It has a flagellum for movement.
11. Euglena contains chloroplasts, allowing it to photosynthesize like a plant.
12. In the absence of light, it feeds heterotrophically, like an animal.
13. Its eye spot detects light, guiding it toward light for photosynthesis.
14. The pellicle provides structural support and flexibility.
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Paramecium

15. Paramecium is a unicellular, ciliated protozoan.
16. It uses cilia for movement and to sweep food into its oral groove.
17. Paramecium has a contractile vacuole to regulate water balance.
18. It feeds on smaller microorganisms like bacteria.
19. The macronucleus controls metabolic functions, while the micronucleus is involved in reproduction.
20. It reproduces both sexually (conjugation) and asexually (binary fission).
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Tissue (Epithelial Tissue and Hydra)

Epithelial Tissue

21. Epithelial tissue lines organs and surfaces in animals.
22. It provides protection, secretion, and absorption.
23. Types include squamous, cuboidal, and columnar epithelium.
24. Squamous epithelium forms thin layers, such as the lining of blood vessels.
25. Cuboidal epithelium is found in glands and kidney tubules.
26. Columnar epithelium lines the stomach and intestines, aiding absorption and secretion.
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Hydra

27. Hydra is a multicellular organism with simple tissues.
28. Its body wall has two layers: the outer epidermis and inner gastrodermis.
29. The epidermis contains sensory and contractile cells for movement and response.
30. The gastrodermis lines the digestive cavity, secreting enzymes for digestion.
31. Hydra has nerve cells arranged in a simple network, enabling responses to stimuli.
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Organ (Onion Bulb)

32. The onion bulb is an organ formed from layers of modified leaves.
33. It stores nutrients for the plant.
34. The bulb's cells contain large vacuoles to store water and sugars.
35. Onion cells have a cell wall, nucleus, and cytoplasm.
36. The transparent structure of onion epidermal cells makes them ideal for microscopic study.
37. The roots of the onion bulb absorb water and nutrients from the soil.
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Organ Systems

Reproductive System

38. The reproductive system ensures the continuation of species.
39. In plants, reproduction involves flowers, seeds, and pollen.
40. In animals, the system includes gonads (e.g., ovaries and testes) and associated organs.
41. Sexual reproduction involves gamete fusion, while asexual reproduction does not.
42. Fertilization can be internal (mammals) or external (amphibians).
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Digestive System

43. The digestive system breaks down food into absorbable nutrients.
44. In humans, it includes the mouth, esophagus, stomach, intestines, and accessory organs.
45. Digestive enzymes (e.g., amylase, lipase) help break down carbohydrates, proteins, and fats.
46. In herbivores, the digestive system is adapted for breaking down cellulose.
47. Simple organisms like hydra have a single opening for ingestion and egestion.
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Excretory System

48. The excretory system removes metabolic waste from the body.
49. In humans, it includes the kidneys, ureters, bladder, and urethra.
50. The kidneys filter blood to remove urea and other nitrogenous waste.
51. Organisms like Paramecium use a contractile vacuole for excretion.
52. Plants excrete waste through stomata and lenticels.
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Organisms (Chlamydomonas)

53. Chlamydomonas is a unicellular green alga.
54. It has a flagellum for movement.
55. Chloroplasts enable it to perform photosynthesis.
56. The pyrenoid stores starch.
57. Chlamydomonas reproduces sexually and asexually.
58. It thrives in freshwater habitats.
59. The eye spot detects light, guiding it toward optimal conditions for photosynthesis.
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Additional Functions and Relationships

60. Cells like Euglena and Paramecium demonstrate both plant-like and animal-like features.
61. Tissues like epithelium specialize in protection, absorption, and secretion.
62. Organs such as onion bulbs showcase the structural and storage roles in plants.
63. Organ systems ensure coordination and survival of multicellular organisms.
64. The organism Chlamydomonas bridges plant and microbial features.
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Microscopic and Functional Analysis

65. Plant cells have chloroplasts for photosynthesis; animal cells do not.
66. Vacuoles in plant cells maintain turgor pressure, aiding structure.
67. Onion cells highlight the typical plant cell structure under a microscope.
68. Paramecium’s contractile vacuole is an example of osmoregulation in unicellular organisms.
69. Hydra shows basic tissue organization and simple nervous systems.

Evolutionary Perspective

70. Unicellular organisms like Euglena show how early life adapted to diverse environments.
71. Tissue formation in multicellular organisms represents an evolutionary step in complexity.
72. Organs like onion bulbs are specialized for nutrient storage.
73. Organ systems in animals display high specialization and coordination.
74. Simple organisms like Hydra and Chlamydomonas illustrate early forms of tissue and organ function.
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Practical Applications

75. Microscopic study of onion cells aids in understanding cell structure.
76. Paramecium is used in research on cell movement and response.
77. Chlamydomonas helps in studying photosynthesis and cellular respiration.
78. Knowledge of epithelial tissues advances medical studies on skin and internal linings.
79. Understanding digestive systems informs dietary science and medicine.
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Ecological Roles

80. Chlamydomonas contributes to oxygen production in aquatic ecosystems.
81. Hydra demonstrates the role of simple predators in freshwater food chains.
82. Paramecium helps control bacterial populations in aquatic environments.
83. Onions are essential crops in human agriculture.
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Energy and Sustainability

84. Euglena's dual feeding mode showcases flexibility in energy acquisition.
85. Paramecium’s ciliary movement exemplifies efficient energy use.
86. Onion bulbs store energy for later use, ensuring plant survival.
87. Chlamydomonas exemplifies photosynthesis-driven energy production.
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Structural and Functional Organization

88. Cellular organization underpins all life forms, from Chlamydomonas to humans.
89. Tissue organization increases efficiency in multicellular organisms.
90. Organs integrate multiple tissues to perform complex functions.
91. Systems coordinate organs for survival and reproduction.
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Diversity and Adaptation

92. Paramecium’s dual nuclei showcase cellular complexity in unicellular organisms.
93. Hydra represents an early form of tissue specialization.
94. Onion bulbs display adaptations for nutrient storage and survival.
95. Chlamydomonas bridges plant-like and microbial features.
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Study and Research

96. Cells like Euglena and Paramecium are model organisms for research.
97. Onion epidermis is a staple in cell biology labs for observing plant cells.
98. Tissues and organ systems help explain human biology and medical conditions.
99. Studying Chlamydomonas informs renewable energy research through biofuel production.
100. Understanding levels of organization enhances our comprehension of life’s complexity.

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