What are monocots and dicots? What is the difference between them? Learn more about these two types of flowering plants and also learn how to devise an experiment to test their properties.
b. The stem also supports and spaces out the leaves to receive enough sunlight and absorb enough carbon dioxide for photosynthesis.
c. The stem holds the flowers above the ground helping in pollination by both insects and wind. It also essential to facilitate seed dispersal.
The stem is divided into several structures:
i. Epidermis which protects the cells underneath.
ii. Strengthening cells which have a thick cell wall and help to support the plant’s stem.
iii. Cortex which is made up of cells that retain large amounts of water. These cells are tightly packed together in order to give further support to the plant.
iv. Cambium which undergoes cell division to give rise to more phloem and xylem vessels.
v. Phloem vessels are tubes that carry food in plants.
vi. Xylem vessels are tubes that carry water in plants.
vii. Pith consists of cells which contain large amounts of water and support the plant.
viii. Hollow found at the centre of the stem
A typical leaf is made up of the leaf stalk or petiole which attaches the leaf to the stem and continues into the leaf as a midrib. Branching from the midrib is a network of veins (in dicots) which deliver water and salts to the leaf cells and carry away the food made by them during photosynthesis. The network of veins also serves as a skeleton to support the softer tissues of the leaf blade. The latter is further divided into the:
i. Upper Epidermis which consists of the cuticle and the epidermis.
ii. Palaside mesophyll which consists of the palaside cells.
iii. Spongy mesophyll which consists of the spongy cells and air spaces.
iv. Lower mesophyll which consists of the guard cells and stomata.
The roots are the under ground part of the plants which does not have chlorophyll. Because of this, the roots have to be supplied with food produced during photosynthesis by the leaves. There are two types of roots which are the fibrous root system and the tap root system.
The internal structures of the root are the:
i. Cortex cells which are used to store food as starch.
ii. Root Hairs which absorb water and mineral salts.
iii. Root cap which protects the growing root tap as it pushes through the soil.