How Plants Talk

1. How Plants Talk Lesson: Objective 1 (5.10) (F) determine a text’s main (or major) ideas and how those ideas are supported with details Grade: 5 (TX)

2. Introduction • Human beings always communicate and send signals when they sense danger. Did you know plants and animals also do the same? Now you can learn about their ways… it’s not a secret anymore. • Today’s lesson carries two very interesting features on how plants and animals send signals to communicate in their daily lives. • The lesson will help you to determine a text’s main (or major) ideas and how those ideas are supported with details. • The main idea that are found in a story are always answers to questions that begin with Who, What, Where, When, and Why. 2

3. How Plants Talk • Have you ever wondered how plants talk to each other? They may not have the same language as humans do but they have their own ways. Think of the lovely scent of fresh cut grass. Did you know that in the plant kingdom this is a danger signal? When attacked, certain plants release airborne chemical compounds. • 2. Plants all over the world have qualities, which make them special in • their own ways. Some plants produce chemicals that give out a • strong odor. Certain leaves and stems emit a strong taste or smell of • chilies, spices and herbs used for cooking. These substances either • discourage or even kill insects and other animals that might try to • eat the plant. • 3. Scientists in Japan describe how the Lima bean plant protects itself and its neighbors from the spider mite or the red spider. It sends out clear distress signals. It’s not like they make weird noises to attract attention, though. It does it very silently. 3

4. How Plants Talk • The Lima bean plant emits chemicals to send the message of a • troublesome intruder to all its neighbors. That is the signal for all • the plants to get their defense mechanisms working. So it is not just a self-survival instinct that plants have. They also have an instinct for community feeling, as the Lima bean plant shows. • 5. Since plants cannot escape from creatures that feed on them, many • have evolved features to protect them against herbivorous or plant • eating animals. The two main defenses that plants use are armor • and poison. In the Galapagos Islands cacti grow a thick stalk more • than two meters tall putting the tender leaves well out of the reach • of the giant tortoises. • 6. Plants can summon insects to their aid to avoid being munched to death by caterpillars, scientists have found. Leafy tobacco plants have found a way to save themselves from caterpillars. A chemical reaction takes place that attracts predatory insects that eat the caterpillars. 4

5. How Plants Talk • Scientists have found that the caterpillars' saliva activates this signal. The caterpillar saliva causes a chemical change. It is quite clear that the caterpillars themselves cause the change. • 8. This results in an odor similar to the smell of cut grass. This in turn sets off a reaction, whereby creatures that eat caterpillars can sense where to find these animals and prey on them. • Japanese azaleas produce toxic chemicals that let them survive even • among hungry deer. Some of these chemical substances may even • prevent the growth of nearby plants. For example, radishes produce a chemical substance, which slows the growth of spinach. Similarly, walnut and apple trees cannot grow together because chemicals released from walnut tree kill the apple tree. • 10. So it is not just a self-survival instinct that plants have. They also • have an instinct for community feeling, as the Lima bean plant • shows. Nature is full of unending surprises! 5

6. Check Your Understanding • What is the passage mainly about? • a. Lima bean plant and fresh cut grass • b. caterpillars and spiders • c. chemicals and odors • d. plants and how they save themselves 6

7. Check Your Understanding • 2. What does the passage tell us? • a. how plants grow • b. functions of the different parts of a plant • c. how plants are attacked by fungus and how decay sets in • d. how plants send distress signals to other plants 7

8. Check Your Understanding • What do most plants emit that act as a protective? • a. poisonous gases / fumes • b. peculiar odors • c. harmful liquids or toxic particles • d. heat 8

9. Check Your Understanding • Which one of these attacks tobacco plants? • a. red spiders • b. beetles and bugs • c. caterpillars • d. leech 9

10. Check Your Understanding • Fill in the blanks. • i caterpillars secrete…………………………. ……………………. • (a) saliva / (b) a sticky venomous fluid • ii this secreted substance gives off ………………………………… • (a) a noisy signal / (b) an odor • iii this reaction attracts ……………………………………………… • (a) snakes / (b) creatures that prey on caterpillars 10

11. Check Your Understanding 6. When certain plants like Japanese azaleas produce toxic chemicals, what happens to other plants? a. they change color b. they stop growing c. they start producing the same odor d. they develop fungus or a type of “rash” 11

12. Check Your Understanding • Which other protective method (apart from odors) do plants and cactus use in Galapagos Islands? • a. they develop sharp thorns which stick to predators and hurt • them • b. they contain blood sucking bugs which attack predators • c. they develop a type of antennae or feelers which can sting the • predators • d. they grow a thick stalk more than two meters tall that protect • the tender leaves within 12

13. Feature # 2 – How Animals Talk • Animals do not talk in the same way as people, but they do have smart ways of communicating. Communication can be smelled, seen, felt, or heard. It helps animals to do things like announce danger, attract a mate, and bond with their kin for hunting and travel. It also warns off predators, mark their territory and identify themselves to other animals. • Various species send signals using sight, sounds, body language, touch, scent, complex chemicals, or a combination of all of these. Close-range visual signals are used to send a variety of messages, such as “Food is near” or “Keep away!” • Birds from peacocks to robins attract mates using bright colors. Fireflies do the same with light. The white flash of a fleeing rabbit’s tail warns others of danger. Dogs, cats, and other animals raise their hackles, arch their backs, or puff themselves up to look bigger. Opossums play “dead” to fool their enemies. 13

14. Feature # 2 – How Animals Talk • Sound signals carry over considerable distances and give information immediately. Songbirds and howler monkeys call to establish territories. Whales, frogs, and crickets sing to attract a mate. Vervet monkeys warn others of different enemies by using different sounds. Intelligent mammals such as chimpanzees communicate with others using sounds, scent, touch, body language, and facial expressions. • Animals use scent signals called pheromones to affect the behavior of others. These complex chemicals, which include hormones, are most often transferred by air. Animals use their senses to find out about the world around them. Most animals have the same five senses as humans, but some have extra senses. Many animals have far sharper senses than humans. • Birds such as falcons have much sharper vision. Some insects can detect ultraviolet light, which we cannot see. 14

15. Feature # 2 – How Animals Talk • A bloodhound’s nose is many times more sensitive than a human’s. Bats, whales, and elephants can detect very high or low sounds that we cannot hear. • Some animals can see quite clearly at night even when there is no moon. The large eyes of night hunters, such as owls, are designed to make the most of very dim light. Many animals active at night, also have extremely good senses of hearing and smell. • Some aquatic animals, including sharks, can pick up tiny electrical signals given off by their prey. It is believed that many migratory animals can detect Earth’s magnetic field to help find their way. • Bats, whales, and dolphins, which hunt in darkness or murky water, make sounds, then listen for echoes to track their prey. The same technique helps them to navigate and avoid collisions with objects. 15

16. Feature # 2 – How Animals Talk 11. Hunting bats and dolphins make streams of clicking sounds, which spread out through the air or water. The sound vibrations bounce back off objects such as flying insects or shoaling fish. The hunter uses its sharp hearing to listen for the returning echoes. These allow it to pinpoint the whereabouts of its victims, so that it can home in on its prey. 16

17. Check Your Understanding • Which one of these is not the usual method used by most mammals as signals for communication or danger? • a. sound and body language • b. color • c. secreting venom / poison • d. giving off complex chemicals 17

18. Check Your Understanding 9. When we see the flash of a rabbit’s white tail, what does it mean? It means: a. he is hungry and looking for food b. an earthquake or flood may happen c. a warning sign of danger d. it is looking for its kin to travel or bond with 18

19. Check Your Understanding 10. Given below are some statements. Mark “T” for true and “F” for false. a. rabbits and skunks play “dead” to fool enemies b. dogs and cats raise their hackles and arch their backs c. fireflies make a loud buzzing sound to attract mates d. peacocks flash their bright colors to attract mates 19

20. Check Your Understanding 11. How do bats, whales and dolphins which hunt in darkenss or murky water find prey, navigate, and avoid collision? a. they let off a ray of ultraviolet light b. they emit distinctive odors which are picked up and returned by their prey, making them trackable c. they give off electrical impulses by flapping their wings / fins d. they make sounds, then listen for echoes 20

21. Check Your Understanding 12. When do howler monkeys and songbirds call? a. when it is time to return home at sunset b. when they want to establish territory c. when danger is near d. when they are hungry 21

22. Check Your Understanding 13. Fill in the blanks. i a. (insects) / b. (bats) ………………. …..can sense ultraviolet light which we cannot see. ii sound signals carry over considerable distances and ………… ………………………….. … a. (take time to travel) / b. (reach immediately). iii birds such as a. (falcon) / b. (owls)…………………………. have good night vision 22

23. Check Your Understanding 14. Do you agree that all animals and humans have the same or equal kind of senses? Which species are more at an advantage / have sharper senses? Can you describe some details of the animals which have an edge over humans? Consider the following fields / senses. a. vision b. smell c. hearing 23

24. Check Your Understanding 15. Discuss any animal habits which you have noticed. Do you think all animals harm / attack humans whenever they come face to face? OR Do they attack only when there is a danger or cause for revenge? e.g. a. how do nesting birds behave when they sense danger? b. do you know what mammals would do if their young ones are threatened? c. when would a snake get ready to strike? 24

25. Summary • Today you have learned some of nature’s secrets. • You have also learned to determine a text’s main (or major) ideas and how those ideas are supported with details. Simply, by asking What, Where, Who, When, and Why, you can get all your answers. 25

26. Great job today!