Lessons 9–10 · 2 lessons · O. Pratov, A. Tukhtaev, F. Azimova, I. Saparboev, M. Umaraliyeva. Biology (Botany), Grade 6. O‘zbekiston Publishing House, Tashkent, 2017
10
The shoot
Textbook: p. 27
GoalName the parts of a shoot (stem, leaf, bud, node, internode) and its kinds.
A shoot is a vegetative organ of a higher plant consisting of a stem with leaves and buds on it. A one-year branch of a tree or shrub that bears buds and leaves is also called a shoot. The stem is the axis of the shoot. The place on the stem where a leaf and a lateral bud sit is the node; the stretch between two neighbouring nodes is the internode. A shoot with only leaves and buds is a vegetative shoot; a shoot that produces flowers is a generative (flowering) shoot. In autumn a shoot changes from green to brown or reddish because its surface thickens and a cork layer forms. In late autumn leaves fall, the buds in their axils are left uncovered and overwinter.
Worked examples
Count the nodes on an apple twig: each node has a leaf (or leaf scar) and a bud; the stretches between are internodes.
In spring an apple shoot with only leaves is vegetative; a shoot that produced flowers is generative. A one-year seedling grown from a seed also counts as a shoot.
Class activity
Observation: in autumn or winter take a 15–20 cm twig of poplar, willow or apple, find the nodes, buds and leaf scars with a magnifier, draw them and measure the internodes. Safety: an adult cuts the twig with secateurs; children do not handle cutting tools.
Practice
1
What parts does a shoot consist of?
Stem, leaves and buds.
2
Tell a node from an internode.
A node is where leaf and bud attach; an internode is the stretch between two nodes.
3
Which shoot is generative: with leaves and buds, or with flowers?