INTRODUCTION TO PLANTS

What are Plants?

Plants are living organisms that covers much of the earth, they consist of leaves, stems and roots. They include trees, shrubs, grass, ferns, mosses, flowers, and more. Plants usually grow in everlasting locations, they absorb water and minerals from the roots, and synthesize leaf nutrients by photosynthesis using the green pigmentation called the chlorophyll. 

 

Plants are part of Kingdom Plantae

 

What makes a plant living?

• They can reproduce - Reproduce Asexually through stems, roots and leaves, and can reproduce sexually through the fusion of male and female gametes in the flower

• They can grow and develop - need sunlight, proper temperature, moisture, air, and nutrients.

• They are sensible and respond to the environment - Sense and respond to life, temperature changes, gravity, chemical, and touch.
  

•  Homeostasis - Internal systems are kept in balance       
  

• They produce food - Plants are able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen in a process called photosynthesis

• plants are made up of cells 

                                         Plant Characteristics:

• They are photosynthetic -  they can convert energy into sunlight to food
  

• Plants are autotrophic - they are producers, they produce food for themselves and also other living organisms through the process of photosynthesis
  

•  They are eukaryotic - contain a nucleus and other membrane-bound organelles (large central vacuoles, cell walls containing cellulose, and plastids such as chloroplasts and chloroplasts.
• They are multicellular - made up of many cells
• They have cell walls made up of cellulose
  

 

 

Two major groups of plants...

 

There are many types of plants in the world, they are divided into two major groups Vascular and Nonvascular.

 

Vascular- also known as Tracheophyta is a are a large group of land plants that have specific tissues that help move substances such as water, nutrients, and other materials in the plants. They are then divided into flowering plants and non-flowering plants. Most organisms that you might think of as plants, such as trees, bushes, and flowers, fall into this group. Example- flowering plants.

9 out of 12 phyla are vascular.

• phylum Pterophyta (Ferns)
  
• phylum Gnetophyta (Gnetophytes- Gymnosperms)
  
• phylum Ginkgophyta (Maidenhair tree Gymnosperm)
  
• phylum Cycadophyta (Cycads- Gymnosperms)
  
• phylum Lycophyta (Club and spike mosses)
  
• phylum Arthrophyta (Horsetails)
• phylum Coniferophyta (Conifers- Gymnosperms) 
• phylum Pteridophyta (Ferns and Horsetails)
• phylum Magnoliophyta (Flowering plants- Angiosperms)

 

Vascular plants are made up of two tissues the Xylem and Phloem. These vascular tissues help allow plants to grow larger and live without any water surrounding them.

 

Xylem tissue- The xylem transports water and dissolved minerals from the roots to the leaves of the plant.

 

Phloem tissue- the phloem transports nutrients from the leaves to the roots, and transports products of photosynthesis.

 

  

Nonvascular- Also known as bryophytes, they lack vascular tissues which transport water and nutrients. the plants are primitive land plants, they can photosynthesis and there cell walls are made up of cellulose. Nonvascular plants have no true roots, stems, or leaves. The plants absorb water and minerals directly into cells by osmosis, they still need water for fertilzation. Example- Moss.  

3 out of 12 phyla are nonvascular.  

• phylum Bryophyta (Mosses)
• phylum Hepatophyta (Liverworts)
• phylum Anthocerophyta (Hornworts)