Plant Anatomy Notes 2023 MSc Botany 2nd Semester.Studying plant anatomy allows a student to conceptually integrate organismal structure and function. Further, it helps to reveal the relationships between structure, function, taxonomy, ecology, and developmental genetics.
Plant anatomy Definition:
Plant anatomy is the study of the tissue and cell structure of plant organs.
What is the importance of plant anatomy?
Plant anatomy is situated between the study of plant morphology and cell biology. Studying plant anatomy allows a student to conceptually integrate organismal structure and function. Further, it helps to reveal the relationships between structure, function, taxonomy, ecology, and developmental genetics.
Who is father of plant anatomy?
Nehemiah GrewNehemiah Grew (26 September 1641 – 25 March 1712) was an English plant anatomist and physiologist, known as the “Father of Plant Anatomy”
What do you call a plant’s body?
Plant body organization
The stems and leaves together make up the shoot system. Each organ (roots, stems, and leaves) include all three tissue types (ground, vascular, and dermal).
- dermal tissue
- vascular tissue
- ground tissue
Dermal Tissue :
The dermal tissue is the outer protective layer of the primary plant body (the roots, stems, leaves, flowers, fruits, and seeds).
Vascular Tissue:
Vascular tissue transports water, minerals, and sugars to different parts of the plant.
What is vascular tissue and its function?
Vascular tissue transports water, minerals, and sugars to different parts of the plant. Vascular tissue is made of two specialized conducting tissues: xylem and phloem. Xylem tissue transports water and nutrients from the roots to different parts of the plant, and also plays a role in structural support in the stem.
Ground Tissue :
The ground tissue system arises from a ground tissue meristem and consists of three simple tissues: parenchyma, collenchyma, and sclerenchyma .
What is the difference between epidermis and periderm?
The epidermis is the outer layer of leaves, young stems, and young leaves, whereas the periderm is the outer layer of roots and stems that have undergone secondary growth.
Epidermis Definition
epidermis, in botany, outermost, protoderm-derived layer of cells covering the stem, root, leaf, flower, fruit, and seed parts of a plant. The epidermis and its waxy cuticle provide a protective barrier against mechanical injury, water loss, and infection.
Parenchyma Tissue
Parenchyma is a type of simple permanent tissue that makes a major part of ground tissues in plants, where other tissues like vascular tissues are embedded.
collenchyma, in plants, support tissue of living elongated cells with irregular cell walls. Collenchyma cells have thick deposits of cellulose in their cell walls .
Sclerenchyma tissue
sclerenchyma, in plants, support tissue composed of any of various kinds of hard woody cells. Mature sclerenchyma cells are usually dead cells that have heavily thickened secondary walls containing lignin.
What is the definition of xylem and phloem?
The vascular system is comprised of two main types of tissue: the xylem and the phloem.
| xylem | phloem |
|---|---|
| The xylem distributes water and dissolved minerals upward through the plant, from the roots to the leaves. | The phloem carries food downward from the leaves to the roots. |
Difference Between Cortex , sclereid and Pith ?
Pith
The pith is a small zone at the center of the stem, consisting of parenchyma cells and originating as a primary tissue from the ground meristem.
Cortex
cortex, in plants, tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues of stems and roots. Cortical cells may contain stored carbohydrates .
sclereid
a variably shaped sclerenchymatous cell of a higher plant.
Leaf Structure
What is leaf structure?
Typically, a leaf consists of a broad expanded blade (the lamina), attached to the plant stem by a stalklike petiole. In angiosperms leaves commonly have a pair of structures known as stipules, which are located on each side of the leaf base and may resemble scales, spines, glands, or leaflike structures.
Adaptations for photosynthesis
Leaves have several adaptations which play an important role in photosynthesis.
| Plant adaptation | Function |
|---|---|
| Broad leaves | Provide a large surface area to absorb as much sunlight as possible. |
| Thin leaves | Provide a short diffusion pathway for gases to move into and out of cells. |
| Network of tubes (xylem and phloem) | To transport water, mineral ions and glucose (food) around the plant. |
| Lots of chloroplast | Contain a green substance called chlorophyll, which traps energy from the sun for photosynthesis. |
| Stomata | Tiny holes found mainly underneath the leaf to allow gases to diffuse into and out of the leaf. Each hole is a single stoma. |
| Guard cells | Controls the opening and closing of stomata. |
| Midrib | Provides strength throughout the leaf, keeping it upright and sturdy in the wind. |
| Petiole | Attaches the leaf to the stem. |
Structure-Function Relationship: Leaves
| Name of Structure | Structure |
|---|---|
| Epidermis | Single layer of thin, closely packed cells |
| Guard cells | Spiral walls, bound at ends |
| Palisade cells | Tall, many chloroplasts, precisely spaced |
| Phloem | Elongated cells, living but without nucleus or ER, connected end to end by sieve plates and plasmodesmata |
What are the 7 parts of a leaf?Leaf
- Apex.
- Midvein (Primary vein)
- Secondary vein.
- Lamina.
- Leaf margin.
- Petiole.
- Bud.
- Stem.
What are leaf structures and their functions?Structure-Function Relationship: Leaves
| Name of Structure | Structure | Function |
|---|---|---|
| Pith | Parenchyma with vacuoles and plastids | Storage, support |
| Plasmodesmata | Openings between sieve tubes connecting cytoplasm | Transport of sap |
| Spongy cells | Rounded, widely spaced, near stomata | Allow gas exchange |
| Suberin | Waxy molecule | Waterproofing |
What is meant by the term periderm?
Definition of periderm:
an outer layer of tissue especially : a cortical protective layer of many roots and stems that typically consists of phellem, phellogen, and phelloderm.
What is meant by primary and secondary growth?
primary growth:
Primary Growth: Primary growth is the growth that occurs by the action of the primary meristem, which increases the length of the stem and adds appendages to the stem.
Secondary growth:
Secondary growth is the growth that occurs by the action of the cambium, which increases the diameter of the plant.
Cambium Definition
The layer of actively dividing cells between xylem (wood) and phloem (bast) tissues that is responsible for the secondary growth of stems and roots .
Stomata Definition
Stomata are cell structures in the epidermis of tree leaves and needles that are involved in the exchange of carbon dioxide and water between plants and the atmosphere.stomata exchange gases.
What is the function of stomata?
Stomata, the small pores on the surfaces of leaves and stalks, regulate the flow of gases in and out of leaves and thus plants as a whole.
function of stomata
- control water lost by transpiration.
- allow gas exchange.
What is the function of guard cell of stomata?
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation. Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.
How do the guard cells regulate?
The guard cells regulate the opening and closing of stomatal pores by the osmosis process. When water flows into the guard cells, they swell up and the curved surface causes the stomata to open. When the guard cells lose water, they shrink and become flaccid and straight thus closing the stomata.
What is the difference between stomata and guard cells?
Stomata of leaves are responsible for providing space for the gas exchange and moisture.Guard cells are responsible to control transpiration and gas exchange in plants. Hence, they are responsible for the opening and closing condition of stomata.
MSc Botany 2nd Semester Notes 2023
| No | Subject | View |
|---|---|---|
| 1 – | Plant Ecology | Download – View |
| 2 – | Genetics | Download – View |
| 3 – | Plant Biochemistry | Download – View |
| 4 – | Plant Physiology | Download – View |
| 5 – | Plant Anatomy | Download – View |