Why leaves turn color in the fall vocab.pptx

Vocabulary

1. Why Leaves Turn Color in the Fall By Diane Ackerman

2. Why Leaves Turn Color in the Fall? When the days begin to shorten, soon after the summer solstice on June 21, a tree reconsider s its leaves. All summer it feeds them so that they can process sunlight, but in the dog days of summer the tree begins pulling the nutrients back into its trunk and roots, pares down , and gradually chokes off its leaves. A corky layer of cells forms at the leaves’ slender petioles, then scars over. Undernourished, the leaves stop producing the pigment chlorophyll, and photosynthesis ceases. Animals can migrate or store food to prepare for winters. But where can a tree go? It survives by dripping its leaves and by the end of autumn, only a few fragile threads of fluid carrying xylem hold leaves to their stem.

3. Vocabulary to think carefully about something again reconsiders pares down to reduce or decrease something chokes off to stop the supply of something corky resembling cork in texture or appearance pigment substance that give color to something photosynthesis the process by which the plants make food from sunlight xylem The tissues in plants that transport water and nutrients words meaning rethinks, reassesses, reevaluates reduces, decreases, minimizes cuts off, stops, blocks rough, bark-like, rugged colorant, dye, hue plant growth, food production, energy creation Vascular tissue, plant vessels, nutrient transport system synonyms

4. Why Leaves Turn Color in the Fall? A turning leaf stays parrot green at first, then reveals splotches of yellow and red as chlorophyll gradually breaks down. Dark green seems to stay the longest in the veins , outlining and defining them. During the summer, chlorophyll dissolves in the heat and sunlight, but it is also being steadily replaced . In the fall, on the other hand, no new pigment is produced, and so we notice the other colors that were always there, right in the leaf. Although chlorophyll’s shocking green hid them from the view.

5. Vocabulary small irregular patches of color splotches veins the vessels that carry fluid in a plant dissolves to absorb a solid in a liquid to make a solution replaced to be substituted in place of something hid simple past of verb “ hide”put out of sight words meaning blotches, spots, patches vessels, arteries, ducts break down, disintegrate, liquify renew, replenished, restored concealed, covered, masked synonyms