2.9 Topic for discussion.
The process of photosynthesis (use figure 2.5).
It is interesting to know
K
oalas
are inactive because their diet gives them very little energy.
Koalas’ favorite food is eucalyptus leaves. Even though there are
over 600 types of eucalyptus trees in Australia, a koala eats the
leaves of only 2 or 3 kinds. Interestingly, eucalyptus leaves are so
poisonous that they can kill most animals. Thanks to their sense of
smell and a special digestive system, koalas have no problem eating
eucalyptus leaves. Koalas sniff a eucalyptus leaf first before eating
it. They do so to be certain that this leaf is from their preferred
types of eucalyptus trees. Koalas’digestive system has a special
function to take the poisons out of eucalyptus leaves so that they
will not get sick. Koalas rarely drink water. Do koalas really not
drink water? No, koalas drink water by absorbing moisture from the
leaves or by sipping raindrops on the leaves.
Unit 3 The crown parts
3.1 Active vocabulary:
shoot |
побег |
acorn |
жёлудь |
a berry |
ягода |
cone |
шишка |
catkin |
серёжка |
nut |
орех |
pod |
стручок |
samara |
крылатка |
limb |
сучок, ветвь |
bough |
сук, ветвь |
branchlet |
веточка, побег |
tube |
трубка |
spur |
подъездная ветка, ус |
leafstalk |
листовая ножка |
3.2 Read and translate the text 1 using the active vocabulary and a dictionary.
Text1
The crown parts and functions
A. Seeds
Flowers or cones hold fertilized seeds. Different trees produce different kinds of seeds (figure 3.1). Some produce seeds in a fleshy covering – a fruit or berry, while other trees produce seeds tucked into the folds of cones or catkins. Other trees produce seeds with wings as well as some produce seed inside nuts or pods. In late summer or fall, the seeds come loose and are scattered by wind, water and wildlife. Within each seed is the soft tissue that is the basis a new tree. Seeds have a tough coating that protects them during dispersal to their new home. These seed pods, cones, flowers and fruit are major markers that help in keying out and identifying a specific species of tree. Not as dependable as a leaf, a fruit or seed pod might only be found at certain times of the year. Reproductive structures are great sources for tree identification. The acorn of an oak is a seed but completely different from a maple’s samara. Not all trees are produced from seeds.
|
|
|
|
|
|
Figure 3.1 Seed Types
Some, like the white or paper mulberry, grow from shoots. But most trees, including oak, pine, hickory, persimmon, grow from seeds.