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Questions and Answers
What does pharmacognosy primarily study?
What does pharmacognosy primarily study?
Which component of the plant cell is considered non-living?
Which component of the plant cell is considered non-living?
Which part of the cell wall serves as the first partition between two cells?
Which part of the cell wall serves as the first partition between two cells?
What is the primary function of the cell wall in plant cells?
What is the primary function of the cell wall in plant cells?
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In plant cells, which of the following components is alive and consists of living materials?
In plant cells, which of the following components is alive and consists of living materials?
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What does a typical plant cell NOT consist of?
What does a typical plant cell NOT consist of?
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Phytotherapy refers to which of the following practices?
Phytotherapy refers to which of the following practices?
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What is the primary goal of the science of pharmacognosy?
What is the primary goal of the science of pharmacognosy?
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What is the primary difference between simple starch grains and compound grains?
What is the primary difference between simple starch grains and compound grains?
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What are aleurone grains primarily composed of?
What are aleurone grains primarily composed of?
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Which of the following substances is considered a protective component found in the plant cell wall?
Which of the following substances is considered a protective component found in the plant cell wall?
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What type of crystals are commonly found as inorganic deposits in plants?
What type of crystals are commonly found as inorganic deposits in plants?
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What defines the structure of fats in plants?
What defines the structure of fats in plants?
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What characterizes the primary cell wall?
What characterizes the primary cell wall?
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Which of the following is NOT true about the secondary cell wall?
Which of the following is NOT true about the secondary cell wall?
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What role do plasmodesmata play in plant cells?
What role do plasmodesmata play in plant cells?
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What is a defining feature of pitted walls?
What is a defining feature of pitted walls?
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What component is considered the living part of a cell?
What component is considered the living part of a cell?
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Which characteristic describes the plasma membrane?
Which characteristic describes the plasma membrane?
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What type of pit is characterized by both bordered and simple features?
What type of pit is characterized by both bordered and simple features?
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What does the protoplast contain?
What does the protoplast contain?
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What is the primary function of the cytoplasm within a cell?
What is the primary function of the cytoplasm within a cell?
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Which of the following types of plastids is responsible for photosynthesis?
Which of the following types of plastids is responsible for photosynthesis?
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What type of substances are ergastic substances found in vacuoles?
What type of substances are ergastic substances found in vacuoles?
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Which organelle is responsible for controlling the activities of the cell?
Which organelle is responsible for controlling the activities of the cell?
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What is the main characteristic of chloroplasts compared to chromoplasts?
What is the main characteristic of chloroplasts compared to chromoplasts?
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What characteristic sets mature plant cell vacuoles apart from those in immature cells?
What characteristic sets mature plant cell vacuoles apart from those in immature cells?
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What is the main function of ribosomes within a cell?
What is the main function of ribosomes within a cell?
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Which of the following correctly describes semi-compound starch grains?
Which of the following correctly describes semi-compound starch grains?
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Study Notes
Pharmacognosy Overview
- Pharmacognosy is the science of nature-derived medicines, pharmaceuticals, and poisons.
- The American Society of Pharmacognosy defines it as the study of the physical, chemical, biochemical, and biological properties of drugs from natural origins.
- It encompasses the search for new drugs from natural sources.
- Key fields within pharmacognosy include:
- Medical Ethnobotany: the study of traditional plant use in a society.
- Ethnopharmacology: the study of the pharmacological evaluation of traditionally used natural drugs.
- Phytotherapy (medical herbalism): the use of plants and plant extracts for therapeutic purposes.
- Phytochemistry (Natural Product Chemistry): the chemical study of bioactive constituents in plants, crucial for new drug discovery.
Plant Anatomy
- Plant anatomy describes the structure and organization of plant cells, tissues, and organs.
- It relates the structure to their development and function.
- It focuses on the structure of plant cells and tissues.
Cell Theory & Structure
- All living organisms are made up of cells.
- Cells are the smallest working units of all living organisms.
- A cell is the smallest unit capable of performing life functions.
Typical Plant Cell
- A typical plant cell has several key parts:
- Plasma Membrane
- Peroxisome
- Chloroplast
- Vacuole
- Golgi Apparatus
- Ribosomes
- Plasmodesmata
- Mitochondria
- Smooth Endoplasmic Reticulum
- Rough Endoplasmic Reticulum
- Nucleus
- Nucleolus
- Nuclear Envelope
- Cell Wall
Plant Cell Parts
- A plant cell is composed of living and non-living material
- Three main components:
- Cell wall (non-living)
- Protoplast (living material within the cell wall)
- Vacuoles (non-living)
Cell Wall
- The cell wall is semi-rigid and non-selectively permeable.
- It is present in plant cells but absent in animal cells.
- It provides protection and support to the cell.
- It's composed of:
- Middle lamella
- Primary cell wall
- Secondary cell wall
Middle Lamella
- The middle lamella is the first partition between two adjacent plant cells.
- Primarily composed of calcium and magnesium pectate.
Primary Cell Wall
- Thin and characteristic of young, growing cells.
- Composed primarily of cellulose molecules.
- Capable of expansion as the cell grows.
Secondary Cell Wall
- Thicker and stronger than primary walls.
- Forms after cell expansion is complete.
- Composed of cellulose, hemicellulose, lignin, and suberin.
- Incapable of increasing in area after formation.
Pits and Plasmodesmata
- Pits are areas in the secondary cell wall where no secondary wall material is deposited.
- Pits enable materials and stimuli to pass between adjacent cells.
- Plasmodesmata are strands of cytoplasm that connect the protoplasts of adjacent cells.
- Aid in cell-to-cell communication and material transport.
- Three types of pits exist: simple, bordered, and half-bordered
Protoplast
- The protoplast is the living component of a plant cell.
- It excludes any non-living components, like crystals, starch grains, and vacuole contents.
- It includes the plasma membrane, cytoplasm, and nucleus.
Plasma Membrane
- The plasma membrane is a phospholipid bilayer.
- It acts as a barrier, regulating the passage of substances into and out of a cell.
Cytoplasm
- The cytoplasm is the gelatinous fluid inside the cell.
- It holds and suspends organelles.
Plastids
- Plastids exist in plant cells and are of three types
- Chloroplasts
- Chromoplasts
- Leucoplasts
Vacuole
- Vacuoles are plant cell structures containing cell sap.
- Cell walls may have thin film of cytoplasm.
- Filled with fluids, including pigments and other substances.
- Membranes surround vacuoles.
- Vacuoles contain pigments (e.g., anthocyanins) which colour petals and other parts of plants.
Ergastic Substances
- Ergastic substances are non-living components in plant vacuoles.
- Types include carbohydrates, proteins, and mineral crystals.
Carbohydrates
- Stored as starch grains which can be simple, semi-compound or compound.
Proteins
- Stored in structures called aleurone grains.
- Aleurone grains include structures named crystalloids and globoids.
Mineral Crystals
- Mainly calcium oxalate or carbonate.
- Can take different forms in cells; such as solitary crystals, rosettes, clusters and raphids.
- Example, cystoliths, are calcium carbonate clusters in cells.
Fats
- Lipids (fats and oils) are widely distributed in plant cells.
- Fats function as protective substances in and on the cells walls.
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Description
Explore the fascinating fields of pharmacognosy and plant anatomy. Learn about the properties of natural medicines and the structure of plant cells and tissues. This quiz covers key concepts from traditional uses of plants to modern drug discovery.
