Botany I

Course CodeBSC104
Fee CodeS2
Duration (approx)100 hours
QualificationStatement of Attainment

Study, Learn, and Work More Effectively Growing and Managing Plants

An introduction to plant physiology and taxonomy, including general botany; morphology and anatomy. 

  • Botany provides a foundation for identifying plants easier and more accurately
  • When you know the physical structure of a plant, you will notice and remember distinguishing characteristics with more ease.
  • Botany provides insights into what makes plants grow, get sick, or die -and that knowledge helps farmers and horticulturists to greater success.
  • Advance your career, improve your job prospects, and develop a better appreciation for the environment.

This course is an essential area of study for anyone who works with plants:

  • Gardeners and Landscapers
  • Environmental Managers and Farmers
  • Nurserymen and Plant Scientists
  • Herbalists and Aromatherapists
  • Teachers and Writers in Horticulture, Environmental Management and Agriculture

Lesson Structure

There are 10 lessons in this course:

  1. Taxonomic Classification of Plants
    • Plant Taxonomy - Botanical/Horticultural Nomenclature
    • The Binomial System
    • Botanical Classification
    • Plant Families and Species
    • Hybrids, Varieties and Cultivars
    • Botanical Keys - How to use a botanical key
    • Key to Plant Groups
    • Key to Plant Phyla
  2. Cells and Tissues
    • Plant Cells - types of plant cells
    • Plant Tissues
    • Primary and Secondary Plant Growth
  3. Specific Vegetative Parts of a Plant
    • Stems - Different Stem Forms
    • Leaves - Leaf Structure and Arrangement
    • Roots - Root Structure (tap root, adventitious roots)
    • Common Botanical Terms
  4. Flowers and Fruit
    • The flower - inflorescence (panicle, umbel, composite head)
    • Fruits - Simple, Aggregate, Multiple
    • Reproductive Growth and Development
    • Pollination
    • Fertilization
    • Fruit setting
  5. Seed and the Developing Embryo
    • Seed Structure
    • Seed Coats
    • Food Storage Organs
    • Embryo
    • Seed Germination - Germination Requirements
    • Stimulation and Inhibition of Germination
    • Plant Reproduction -Propagation of Plants
  6. Photosynthesis and Growing Plants
    • Photosynthesis - the Photosynthetic Apparatus
    • Light transformation into energy
    • Photosynthetic process
    • Gas Exchange with the Atmosphere
  7. Respiration
    • Stages of Respiration
    • Krebs Cycle
    • Electron Transport Chain
    • Rate of Respiration
    • Control of ATP Production in Respiration
  8. The Role of Water
    • Osmosis
    • Water Movement from Soil to Root
    • Development of Root Pressure
    • The Transpiration Stream
    • Transpiration and Environmental Conditions
  9. Movement of Water and Assimilates through a Plant
    • Mechanisms of Nutrient Uptake
    • Absorption and Transport of Mineral Nutrients
    • Translocation of Sugars
    • Adaptations for Water Storage
    • Food and Water Storage Organs
  10. The Effects of Tropisms and Other Growth Movements
    • Plant Hormones
    • Tropisms
    • Phototropism
    • Geotropism
    • Thigmotropism
    • Other Growth Movements
    • Chemical Growth Modifications

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Aims

  • Understand the relationship between the scientific principles of this unit and horticultural practices
  • Demonstrate a knowledge of the Plant Kingdom and understanding of the taxonomic hierarchy
  • Identify and describe the different types of plant cells and tissues, their structure and function
  • Determine the role and function of specific vegetative parts of the plant
  • Determine the role and function of the reproductive parts of the plant
  • Demonstrate an understanding of the role and function of the seed in the life cycle of the plant
  • Explain the mechanism and the role of photosynthesis in the metabolism of plants and relate to plant growth in controlled environments
  • Explain the mechanism and the role of respiration in the metabolism of plants
  • Demonstrate an understanding of the role of water in the plant
  • Review the movement of water, solutes and assimilates through the plant
  • Understand the effects of tropisms and other plant movements on growth and development
  • Undertake risk assessments relevant to the learning outcomes in this unit

Why Should You Study Botany?

Botany forms a foundation for much of our world. Without an understanding of botany, we cannot properly manage plants; and without an ability to manage plants we would not be able to grow crops or fodder for farm animals; we would lack effective forestry, landscape or nursery industries; and we would not have the tools needed to rehabilitate or stabilize damaged soils.
Clearly, for anyone who works with the environment, animals or plants; a knowledge of botany; at least to the level covered in this course, is very important.
 
Unfortunately, despite it's significance; the study of botany has not always been given the priority it should have; and as a result, it is not uncommon for significant and costly mistakes to be made. Plants are planted in the wrong places, and all too often not managed well.
 
 
If you work or wish to work in any of these plant related industries; you can become more efficient at your work, save money for employers (or clients), and raise your career prospects by studying this course.
 
This course will give you a foundation and framework to build on, that will help you make sense of plants and how they grow -and that will help you to see possibilities and deal with challenges, that might otherwise be under exploited.
 
 
Do You Understand What makes up a Plant?

Plants have four main parts:

  1. Roots  the parts which generally grow below the soil
  2. Stems  the framework
  3. Leaves required for respiration, transpiration and photosynthesis
  4. Reproductive Parts   flowers and fruits.

STEMS

The main stem and its branches are the framework that supports the leaves, flowers and fruits. The leaves, and also green stems, manufacture food via the process known as photosynthesis, which is transported to the flowers, fruits and roots.  The vascular system within the stem consists of canals, or vessels, which transfer nutrients and water upwards and downwards though the plant (i.e.: This is equivalent to the blood system in animals).

Stems may be modified for a variety of reasons. Some modifications are:
• tendrils ...  instead of a defined branch, the stem is modified into a climbing tendril with leaves appearing periodically along the tendril
• thorns ...  thorns appear along the stem. It is in fact a modified stem. eg. Bougainvillea
• prickle ...  sharp appendage of the epidermis of the stem i.e. it is a trichome. It is not morphologically a stem, leaf, etc. eg. Rosa spp.
• stolon or runners ...  above ground eg. Strawberry (Fragaria vesca)
• rhizome ...  below ground eg. Canna spp.
• stem tubers ...  large fleshy storage regions  eg: potato
• corm ...  function as a food storage to carry the plant over till next season  eg: gladioli
• cladodes and phylloclades ... a cladode is a branch of a single internode which is flattened to simulate a leaf. A phylloclade is an entire shoot similarly flattened.

LEAVES

The primary function of leaves is photosynthesise, which is a process in which light energy is caught from the sun and stored via a chemical reaction in the form of carbohydrates such as sugars.  Leaves are also the principle plant part involved in the process known as transpiration whereby water evaporating, mainly through the leaf pores (or stomata), sometimes through the leaf cuticle (or surface) as well, passes out of the leaf into a drier external environment. This evaporating water helps regulate the temperature of the plant. This process may also operate in the reverse direction whereby water vapour from a humid external environment will pass into the drier leaf. The process of water evaporating from the leaves is very important in that it creates a water gradient or potential between the upper and lower parts of the plant. As the water evaporates from the plant cells in the leaves then more water is drawn from neighbouring cells to replace the lost water. Water is then drawn into those neighbouring cells from their neighbours and from conducting vessels in the stems. This process continues, eventually drawing water into the roots from the ground until the water gradient has been sufficiently reduced. As the water moves throughout the plant it carries nutrients, hormones, enzymes etc. In effect this passage of water through the plant has a similar effect to a water pump, in this case causing water to be drawn from the ground, through the plant and eventually out into the atmosphere.

A leaf consists basically of a petiole (stalk of the leaf) and a lamina (blade of the leaf).  The leaf may be simple or compound (compound leaves consist of a number of smaller leaflets).

There are many leaf modifications that may occur including :
• stipules   at the base of the petiole appearing like winged leaves  eg: peas
• leaf sheath ...  leaf base surrounded by a sheath which encases the stem.  eg. grasses and sedges.
• ochrea ...  a membranous sheath arising from the leaf base and surrounding the axillary bud and stem for a short distance above the node. eg. Polygonaceae family.
• bulbs ...   storage tissue  eg: daffodil, onion
• ligule  ... a small membranous or ciliate appendage at the top of the leaf sheath in most grasses.
• tendrils ... the leaf is modified into a tendril. Identifiable due to the bud at the base of the tendril with frequently large stipules. eg. peas.
• leaf spines ... small spines either on the margins or the whole leaf. Have buds at the union with the stem which indicates a modified leaf. eg thistle and Opuntia spp.
• phyllode ... characteristic of Acacias where the lamina is very small and the petiole is enlarged.
• pulvinus ... swelling at the base of the leaf and leaflets, provides the ability to allow movement by  turgidity  eg: Mimosa pudica
• auricle ...  small ear like appendage on grasses
• cataphylls ...  reduced leaves at base of plant eg. bud and rhizome scales.
• hypsophylls ...  reduced leaves on apex of plant eg. bracts, floral leaves.

ROOTS

Soil provides the plant with the following things:
a) Nutrients
b) Water
c) Air
d) Support
Roots absorb nutrients, water and gasses transmitting these "chemicals" to feed other parts of the plant. Roots hold the plant in position and stop it from falling over or blowing away. Plant nutrients can be supplied, broadly speaking, in three different forms:

1.  Water soluble simple chemical compounds.   Nutrients in these compounds are readily available to plants (i.e.: The plant can absorb them quickly and easily).

2.  Less soluble simple chemical compounds.  The nutrients in these compounds can be used by plants without needing to undergo any chemical change, but because they don't dissolve so easily in water, they aren't as readily useable as the more soluble compounds. The diminished solubility may be because of the nature of the compound (eg: superphosphate) or may be due to something else (eg: Slow release fertilisers such as osmocote, which is made by incorporating the simple chemicals inside a semi permeable bubble   thus nutrients move slowly out of the bubble).  This second group of nutrients when placed in soil will last longer than the first group of water soluble nutrients.

3.  Complex chemical compounds.  These require chemical changes to occur before the nutrients can be absorbed by plants. They include organic manures and fertilisers which need to be broken down by soil micro organisms into a form which the plant can use. They also include other complex fertilisers which need to be affected by natural acids in the soil, or heat from the sun, to become simple compounds which the plant roots can use.
 
Complex chemicals release their nutrients gradually over a long period of time, depending on the range of chemical changes needed to take place before the plant can use them.  Plants grown in a soil derive their nutrients from all three types of compounds. The availability of these compounds varies according to not only the group they come from but also according to factors such as heat, water, soil acids and micro-organisms present. As such, it is impossible to control the availability of nutrients in soil to any great degree.

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