Plant Biology Lecture PDF

PLANT BIOLOGY 6. Vascular system, seed a. Xylem (malalim) - water; upward BOTANY b. Phloem (pagkain) - food;...

PLANT BIOLOGY 6. Vascular system, seed a. Xylem (malalim) - water; upward BOTANY b. Phloem (pagkain) - food; - Plant Science upward and downward - Deals with the study of plants, 7. Medicinal, food source - herbal including their structure, plants have medicinal properties properties, biochemical 8. Alternation of Generation processes, and interactions with - In the course of their life the environment. cycle, plants alternate between two separate life THEOPHRASTUS stages or generations. - Father of Botany 9. Pollination/Fertilization - The - Systematically document on how transfer of pollen from the anther plants grow; he categorized them. to the stigma of a flower. - His works lay the groundwork for the taxonomic system of plants. Key Terms: - Haploid: Having a single set of WHAT ARE PLANTS? chromosomes (n). THE PLANT - Diploid: Having two sets of - Living organisms in Kingdom chromosomes (2n). Plantae - Multicellular organisms that make Reproductive Structures: their own food (autotroph) - Gametangia: Reproductive structures that produce gametes. CHARACTERISTICS OF PLANTS - Antheridia: Male reproductive structures; sperm cells 1. Eukaryotic - Plant cells have - Archegonia: Female reproductive defined nucleus (enclosed in a structures; egg cells nuclear membrane) and other membrane-bound organelles. Reproductive Cells: 2. Multicellular - made up of many - Gametes: Sex cells (sperm and cells egg). 3. Producer - autotrophs; utilize energy from the sun to convert Life Cycle Stages: light energy to chemical energy - Spores: Haploid cells produced 4. Photosynthesis - process of by sporophytes. They can making their own food develop into new gametophytes. 5. Cell Wall - give structural support; - Zygote: A fertilized egg, the first cellulose cell of a new diploid organism. 1|Page Cell Division: 3. Fertilization: When the sperm and - Mitosis: two (2) identical diploid egg meet, they form a zygote, cells. which is diploid. This zygote grows - Meiosis: four (4) haploid cells into a new sporophyte, and the (spores or gametes). cycle starts over. Plant Generations: In other words… - Gametophyte (sexual phase): The haploid phase. It produces 1. Sporophyte Stage (spores) gametes (sex cells) through Diploid (2 sets of chromosomes) mitosis. Produces haploid spores (1 set of - Sporophyte (asexual phase): The chromosomes) through meiosis diploid phase. It develops from Spores grow into... the zygote and produces spores through meiosis. 2. Gametophyte Stage (gametes) Haploid (1 set of chromosomes) Produces gametes (sperm and ALTERNATIONS OF GENERATION egg) through mitosis Sperm + Egg = Fertilization 3. Zygote Formation Diploid zygote is formed Grows into a new sporophyte Cycle continues again…. POLLINATION (FERTILIZATION) 1. Sporophyte Stage: This is the part - Process of transferring pollen of the plant’s life where it makes grains from the male anther of a spores. The sporophyte is diploid, flower to the female stigma which means it has two sets of chromosomes. It creates haploid TYPES OF POLLINATION spores (one set of chromosomes) Anther (male) to stigma (female) through a process called meiosis. - Autogamy (1) - self-pollination; 2. Gametophyte Stage: The spores same plant grow into the gametophyte. This - Geitonogamy (2) - different stage is haploid, and it makes the flowers; same plant (pollinating a plant’s sex cells, or gametes ‘neighbor’) (sperm and egg), through mitosis. - Xenogamy (11) - cross pollination; different plants 2|Page  a. One hydrophilic head (phosphate) b. Two hydrophobic tails (fatty acids) Vacuoles - Most prominent structure; central large vacuole - It fills much of plant cells - Serves as a storage and waste area - Some of the plants contains poison (tannin) to scare away A. THE PLANT CELL: MAIN STRUCTURES animals Vacuole and Turgor Pressure Cell Wall - First cell structure discovered by Robert Hooke in 1665 - Defines the shape of the cell - Contains the cellulose A. Primary cell wall - Allows for cell expansion during growth B. Secondary cell wall - Lignified (woody) - Once a secondary cell wall forms, a cell cannot grow Plant cells prefer a hypotonic solution, anymore where the concentration of solute inside the cell is greater than the concentration Cell Membrane outside the cell. This causes water to - Selectively permeable move into the cell through osmosis. membrane that controls what’s - In a hypotonic solution, water going in and out of the cell flows into the cell, making it turgid, - Serves as a gate which is the desired state for plant - Composed of phospholipid cells. bilayer 3|Page Cytoplasm Why does chloroplast have its own DNA? - Everything within the cell - Chloroplasts have their own DNA membrane which is not the because they were once free- nucleus is the cytoplasm. living bacteria. - Contains cytosol - Endosymbiosis theory by Lyn - organelles are suspended Margulis. here - cytosol + organelles - Nucleus nucleus = cytoplasm - Carries the genetic material of a - Protoplasm - nucleus is plant embedded here - Control center - Nucleus is normally the largest Chloroplast (and other plastids) organelle within a eukaryotic cell - Presence of plastids that make or store food Ribosome - Most common plastid is - The site of protein synthesis chlorophyll - the site of - They are not surrounded by a photosynthesis membrane. - Each chloroplast encloses a - Most common organelles in system of flattened, membranous almost all cells. sac called thylakoids, which - They exist in two sizes: contain chlorophyll. a. 70s - found in prokaryotes, - The space between the grana is chloroplasts, and filled with cytoplasm-like stroma. mitochondria, free- floating; Endosymbiosis Theory by Lyn Margulis. b. 80s - found in eukaryotes, attached to rough ER, larger i. Polysomes - group of 80s working together. - Thylakoids - site of light dependent reaction of photosynthesis - Stroma - site of dark reaction of photosynthesis 4|Page  Mitochondria A. THE PLANT CELL: MAIN STRUCTURES - Powerhouse of the cell - Organelle responsible for Endoplasmic Reticulum breaking down glucose into - System of membranous tubules simpler units and sacs. - Carbon dioxide, water, ATP - It acts as an internal transport (by-products) system, allowing molecules to - ATP is the energy currency of the move from one part of the cell to body. another. Types of Endoplasmic Reticulum B. PLANT TISSUES a. Rough ER - Studded with 80s ribosomes Types of Plant Tissue - Site of protein synthesis 1. Meristematic tissue b. Smooth ER 2. Dermal tissue - Do not have ribosomes 3. Vascular tissue - Polypeptides are 4. Ground tissue converted into functional proteins. A. MERISTEMATIC TISSUE - Proteins are prepared for - “Meritos” - to divide secretion. - Cells remain forever young. - Site of lipid and steroid - Undergo cell division. synthesis. - Plant has four (4) kinds of - Associated with the Golgi meristems. (ALI) complex. Dictyosomes - Golgi bodies in plants. - Process, package, and secretes organelles - Common in glandular cells. - System of membranes; made of flattened sac-like structures called cisternae. - Works closely with the smooth ER to modify proteins for exports by the cell. 5|Page Kinds of Meristem move water, nutrients, and food. A. Apical Meristem - elongation; tips of roots and shoots; produces primary In short… meristems Protoderm (dermal tissue) = a. Protoderm becomes the plant’s “skin” b. Ground meristem Ground Meristem (ground tissue) c. Procambium = becomes the “filler” tissue for support and food storage B. Lateral Meristem - secondary growth of Procambium (vascular tissue) = the plant; thickness becomes the plant’s “pipes” for a. Vascular cambium transport; develops into the b. Cork cambium vascular tissue: xylem and phloem C. Intercalary Meristem - monocots, internodes and leaf bases; regrowth Re: B. Lateral Meristem Lateral Meristem Re: A. Apical Meristem - Also known as cambium - Occurs at the lateral areas (stem, A. Protoderm leaves, roots) - This is the outermost layer of - Facilitate growth in thickness or a young plant. girth in a maturing plant - It develops into dermal - Two main types lateral tissue, which becomes the meristematic tissue: plant’s protective “skin” a. Vascular cambium - secondary growth in stems B. Ground Meristem and roots; produces new - This is the middle layer of a xylem (wood cells) outside, young plant. phloem - inside - It develops into ground b. Cork cambium - bark layer tissue, which makes up outside of stems most of the plant and helps with support, storage, and photosynthesis. C. Procambium - This is the innermost layer of a young plant. - It develops into vascular tissue, which forms the plant’s “transport system” (xylem and phloem) to 6|Page Re: C. Intercalary Meristem B. DERMAL TISSUE - “Derma”, “skin” - Occur only in monocots, at the - Protects the outer part of the plant bases of leaf blades and nodes - Begin as parenchyma cells, which (areas where leaves are attached are then modified to form various to a stem) type of cells for protection - Enables the monocot leaf blade to increase in length from the leaf A. Epidermis base. - Secretes cuticle, a waxy substance that protects the plant from water loss In other words… B. Stomata - Openings of the epidermis Apical Meristem - Regulates exchange of ✓ Found at the tips of roots and gases in and out of the shoots (the ends of the plant). plant ✓ Helps the plant grow taller or C. Trichomes longer. - Extension of the epidermis that controls or regulates Vascular Cambium (a type of Lateral heat and water balance in Meristem) the leaf ✓ Found between the wood D. Root hairs (xylem) and bark (phloem). - Outgrowth of epidermis ✓ Helps the plant grow thicker or - Keeps the plant root in wider (secondary growth) contact with the soil for ✓ Also produces new xylem stronger attachment Cork Cambium (also a Lateral Meristem) ✓ Found near the outer part of stems and roots. ✓ Produces the outer protective layer, like bark. Intercalary Meristem ✓ Found at the base of leaves or where leaves and stems meet (common in grasses). ✓ Helps the plant grow quickly after being cut or grazed. 7|Page In other words… D. GROUND TISSUE - Also called as a fundamental ✓ The dermal tissue is the plant’s tissue system protective covering. - Consist of all the tissues other than ✓ The epidermis is the outermost the vascular and dermal tissue layer; secretes cuticle system ✓ Stomata (singular: stoma) are like - Usually formed between the pores for breathing and water dermal and vascular tissue were control by closing and opening. they are known as the cortex ✓ Trichomes are small hair-like structures on leaves and stems; A. Parenchyma protect the plant from pests, - Living tissue reduce water loss, or help keep it - Soft tissue cool by reflecting sunlight. - For repair, photosynthesis, ✓ Root hairs help the plant absorb and storage more water and nutrients; increases surface area B. Collenchyma - Living tissue - Flexible support for growing parts C. VASCULAR TISSUE C. Sclerenchyma - Transport food and water - Dead tissue internally throughout the - Mechanical support and plant aids in food and water transport. Two Types of Vascular Tissue A. Phloem - food/sugar, up and down; two-way B. Xylem - water, one-way 8|Page  Root Hair C. PLANT ORGANS - Tiny, hair-like projections that emerge from the surface of young 1. Roots root cells 2. Stem 3. Leaf Secondary Root 4. Flower - Also known as lateral root; 5. Fruits branches off from the primary root 1. ROOTS - Essential plant structures In other words… - Grow underground and serve several crucial ✓ Root cap - protects the tip of functions the root. ✓ Root hair - absorbs water and Root Functions: nutrients; increases surface - Absorbs water and dissolved area materials from the soil. ✓ Secondary root - supports the - Anchors the plant to the soil. primary root - Aids in the conduction of water. - It is for reproduction. Regions of Roots Root Parts Region of root cap Root Cap Region of cell division Root Hair Region of elongation Secondary root Region of maturation 1. Region of Root Cap - This is the tip of the root. - It protects the root as it pushes through the soil and guides its direction of growth. - Secretes mucilage - Involved in gravitropism Root Cap 2. Region of Cell Division - Tip of the root - Located just below the root - Regulate the primary growth of cap. the root at the tip - This is where new cells are produced “growth factory.” 9|Page  - Contains the apical In other words… meristem; actively dividing cells Regions of…. ✓ Root Cap: tip of the root, 3. Region of Elongation protection. (Undifferentiated) ✓ Cell Division: New cells are made. - Above the cell division ✓ Elongation: Cells grow longer to zone. lengthen the root; - This is where the new cells undifferentiated grow longer, making the ✓ Maturation: Cells develop to root extend deeper into the perform specific tasks soil. (differentiated) 4. Region of Maturation (Differentiated) - The uppermost part of the Types of Roots root. - Primary roots - This is where cells fully - Adventitious roots develop into their specific - Taproot roles, like absorbing water, - Fibrous roots providing support, or - Modified roots forming root hairs. a. Epidermis - 1. Primary Root (radicle) outermost; covers - The first organ to appear when a the root seed germinates. b. Cortex - contains - It develops from the primary root the parenchyma of the seedling into either taproot c. Endodermis - single or a fibrous root system. layer of cell - The first root that grows from a connecting the seed. vascular cylinder 2. Adventitious Root - Roots that grow from unexpected places, like stems or leaves. - They provide extra support or help with reproduction. - Example: Roots of a corn plant or banyan tree. 10 | P a g e  3. Taproot TYPES OF MODIFIED ROOTS - A single, thick main root that - Stilt roots grows deep into the soil. - Aerial roots - Smaller side roots grow from it. - Floating roots - Example: Carrots, radishes, or - Storage roots mango trees. 4. Fibrous Root - Stilt Roots: Large, above ground - A network of thin, shallow, roots, typically in rainforest, lower branching roots that spread out part of the stem; for extra support close to the soil surface. (e.g., maize) - Helps prevent soil erosion. - Aerial Roots: Air; above ground for - Example: Grasses, rice, wheat. support or moisture (e.g., orchids). - Floating Roots: In water plants for 5. Modified Roots oxygen (e.g., water hyacinth). - Specialized roots with unique - Storage Roots: Store food or water functions: (e.g., carrots). ✓ Storage Roots: Store food or water (e.g., sweet potatoes). 2. STEM ✓ Aerial Roots: Grow above ground - continuation of the root system for support or breathing (e.g., that normally grows above the mangroves). ground ✓ Climbing Roots: Help plants climb - Shoot consists of a stem with (e.g., vines). branches and leaves. ✓ Prop Roots: Extra support for heavy plants (e.g., corn). Functions: - Conduction of materials from roots to leaves and vice-versa In other words… - Storage of food - For reproduction ✓ Primary Root: First root from the - For photosynthesis; and seed. - Supports the leaves, branches, ✓ Adventitious Root: Grows from even flowers different plants of the plants like the stem or leaves ✓ Taproot: A deep, main root; mango ✓ Fibrous Root: Thin, branching roots near the surface; weeds ✓ Modified Roots: Roots with special functions like storage, support, or climbing. 11 | P a g e