Plant Form & Function Quiz

Plant Form & Function

• Plants need sunlight, water, nutrients from the soil, and air to grow.
• Plants absorb inorganic substances like water and carbon dioxide (CO2).
• Through photosynthesis, plants convert these inorganic compounds into organic compounds like glucose and oxygen (O2).

How Important is Water to Plants?

• Water is essential for plant survival.
• Plants use micronutrients from the soil.
• Some plants have root hairs that increase their surface area for absorbing water.

Root Nodules

• Root nodules in some plants are a symbiotic relationship between legumes and bacteria.
• Bacteria help convert nitrogen gas into ammonia.

Transport System in Plants

• Vascular tissues in plants allow the transport of substances from one part of the plant to another.
• The main vascular tissues are xylem and phloem.

Xylem and Phloem

• Xylem transports water and minerals from the roots to the rest of the plant.

• Xylem is made of tracheids and vessels.

• Tracheids do not flow continuously.

• Vessels are hollow tubes that stretch from the roots to leaves.

• Xylem fibers provide structural support.

• Xylem parenchyma cells store food, and are the only living cells in the xylem that assist with food storage.

• Xylem is strengthened by lignin.

• Different patterns of lignin exist, and these vary based on the xylem's location.

• Phloem transports manufactured food (like sucrose and amino acids) from the leaves to other plant parts.

• Phloem consists of sieve tubes and companion cells.

• Sieve tubes are elongated, thin-walled cells with sieve pores that conduct food.

• Companion cells carry out essential processes.

• Companion cells have abundant cytoplasm and are extremely thin-walled.

Transport System in Plants

• These tissues are physically close to each other enabling an efficient transport system.

Plant Nutrition

• Plant nutrition is the supply and absorption of essential chemical compounds.

• These compounds are necessary for plant growth.

• There are 17 essential elements required by plants. (List provided in the presentation)

Adaptive Mechanisms of Plants

• Plants adapt to various conditions to ensure nutrient acquisition.
• They alter growth patterns responding to stress and nutrient availability.
• Plants use various metabolic pathways for efficient nutrient use.
• Plants use physical and chemical barriers to protect against pathogens.
• Plant hormones (like auxin, cytokinins, ethylene, gibberellins, brassinosteroids, and jasmonic acid, and salicylic acid).regulate the development and signal networks of the plant.

Asexual Reproduction in Flowering Plants

• Many plants reproduce asexually through their vegetative parts (stems, roots, and leaves).
• The new plant is genetically identical to the parent plant.

Methods of Artificial Vegetative Propagation

• Cutting: Leaves, stems, or roots are cut from a plant, and then planted.
• Budding and grafting: Small stems or buds from one plant are attached to the stem or root of another plant.
• Tissue culture: Pieces of a plant are placed in a sterile medium to grow new plants.

Modified Stems

• Runners: New plants arise from stem nodes above ground. (Ex. Strawberry Plants)
• Rhizomes: New plants arise from nodes of horizontal underground stems. (Ex. Ginger and Sugarcane)
• Corms: Short thick underground stems with thin scaly leaves. (Ex. Gladiolus)
• Tubers: New shoots arise from auxiliary buds on short swollen underground stems. (Ex. Potato)
• Bulbs: New bulbs from axillary buds, with short stems and thick fleshy leaves. (Ex. Garlic and Onions)

Sexual Reproduction in Flowering Plants

• All flowering plants reproduce sexually through the flower.
• Flowers can be perfect (hermaphrodite) having both male and female parts, or imperfect (one sex only).
• Specialized structures (petals, sepals, receptable, peduncle, stamen (anther and filament), and pistil (stigma, style, ovary)) form the flower.

Stages of Sexual Reproduction in Plants

• Pollination: Pollen transfer from the anther to the stigma. (Wind, water, insects, and other animals.)
• Self-pollination: pollen is transferred to the other part of the same plant.
• Cross-pollination: pollen is moved to the stigma of another plant.
• Fertilization: Pollen tube grows from the stigma to the ovule, uniting with the egg.
• Seed dispersal: Seeds are transported away from the parent plant.
• Germination: Seed absorbs water and oxygen forming into a new plant.