Everything Life Sciences Grade 10

Figure 6.3: A comparison between monocots and dicots.

endosperm

cotyledon

cotyledon

cotyledons

Monocotyledon Dicotyledon

coleoptile coleoptile

epicotyl

epicotyl

epicotyl

hypocotyl

hypocotyl

hypocotyl

hypocotyl

root root

first

leaf

first

leaves

radicle

radicle

radicle

seed coat

fused to

ovary wall

seed

coat

seed

coat

seed

coat

radicle

Figure 6.4: Comparison of a monocot seedling (left) and dicot seedling (right).

In the previous chapter you learnt about the key plant tissues involved in support and trans-

port functions, namely the xylem, phloem, collenchyma and sclerenchyma. Recall that these

tissues are involved in both transport and supporting roles in plants. In different parts of the

plant, tissues are arranged differently. In this section, we will study the overall structure (or

anatomy) of dicotyledonous plants.

Root anatomy DUMMY

Root systems are responsible for the following functions:

• absorptionof water and organic compounds;


• anchoringof the plant body to the ground; and


• storageof food and nutrients.

When a seed germinates, the first structure to appear is the root or theradicle. This becomes

theprimary root. Other roots that branch out of the primary root are calledsecondary

roots(Figure 6.5). The growing root tip is protected by theroot capas it moves through the

coarse soil. The root cap is slimy in nature to facilitate easy movement. Above the root cap

is theapical meristem. In this meristematic region, cells divide continuously by mitosis to

160 6.2. Anatomy of dicotyledonous plants