B4 organising plants and animals Flashcards

Question

What does phloem do?

Answer 1

Transport the glucose made from photosynthesis from the leaves to the other parts of the plants.It also transports food to the storage area where it can be used in winter.Phloem cells are alive.

Answer 2

Carries water and mineral ions from the roots in the soil to the mesophyll cells to use in photosynthesis.xylem cells are dead.In most plants the xylem is the wood.

Answer 3

the cells need glucose for respiration and the mineral ions are used in making cells and proteins.

Answer 4

A potometer is a device used to measure the rate of water uptake by a plant, which is closely related to the rate of transpiration. Transpiration is the process where water moves from the roots through the plant and evaporates from the leaves.

Answer 5

A pacemaker is a small device that's implanted in the chest to help control the heartbeat. It uses electrical pulses to stimulate the heart to beat at a normal rate if it's beating too slowly or irregularly. It replaces the cells in the right atrium.

Answer 6

A stent is a small mesh tube that's used to treat narrowed or blocked arteries. Think of it like a scaffold that helps to keep the artery open, allowing blood to flow freely. They are commonly used in procedures like angioplasty.

Answer 7

Bypass surgery is a surgical procedure that improves blood flow to an area of the body. It involves creating a new route, or "bypass", around a blocked or narrowed artery. This allows blood to flow freely to the heart, brain, or other organs and tissues.

Answer 8

Light Intensity: Higher light intensity usually increases the rate of transpiration because it causes the stomata to open more widely, facilitating gas exchange and water vapour release. Temperature: Increased temperature generally increases the rate of transpiration. This is because higher temperatures increase the rate of evaporation of water from the leaf surface and decrease the humidity of the air surrounding the leaf. Humidity: High humidity decreases the rate of transpiration. If the air surrounding the plant is already saturated with water vapour, the driving force for water to evaporate from the leaf is reduced. Wind Speed: Increased wind speed tends to increase the rate of transpiration. Wind removes the humid air from around the leaf, replacing it with drier air, which increases the rate of evaporation.

Answer 9

Translocation is the movement of sugar produced in photosynthesis to all other parts of the plant for respiration through the phloem.

Answer 10

Phloem is adapted to its role of transporting sugars and other organic nutrients throughout a plant through several key features: Sieve Tubes: These are long, cylindrical cells connected end-to-end, forming continuous tubes for easy flow of substances. Sieve Plates: The end walls of sieve tube elements have pores, called sieve plates, which allow solutions to flow from cell to cell. Companion Cells: These cells are closely associated with sieve tubes and provide them with metabolic support, as sieve tubes lack nuclei and ribosomes. Companion cells help load and unload sugars into the sieve tubes. Living Tissue: Phloem is composed of living cells, which allows it to actively transport substances using energy. This is essential for translocation, the process of moving sugars from source to sink.

Answer 11

Dead Cells: Xylem is composed of dead cells. Because they are dead, there's no cytoplasm to impede water flow, creating a clear, unobstructed pathway. Lignin: The cell walls of xylem vessels are reinforced with a substance called lignin. This provides strength and support, preventing the vessels from collapsing under the negative pressure tension created by transpiration.

Answer 12

Evaporation is the process where liquid water changes into water vapour from any free water surface, like a puddle, lake, or even a wet surface. It's driven by heat energy. Transpiration is the process where water moves through a plant and evaporates from aerial parts, such as leaves, stems, and flowers.

Answer 13

Water Transport: It helps move water and dissolved minerals from the roots to the leaves. Cooling: It cools the plant through evaporation, similar to sweating in animals. Turgor Pressure: It maintains turgor pressure in cells, which is essential for plant rigidity and growth. Photosynthesis: It supplies water for photosynthesis.

Answer 14

Guard Cells: Each stoma is flanked by two specialised cells called guard cells. These cells regulate the opening and closing of the stomatal pore. They are kidney-shaped and their differential swelling and shrinking control the size of the stomatal aperture. Stomatal Pore: This is the actual opening or pore between the guard cells through which gases like carbon dioxide and oxygen, and water vapour pass.

Answer 15

Stomata open to allow carbon dioxide CO2 to enter the leaf for photosynthesis. They also allow oxygen O2 , a product of photosynthesis, to exit. The opening and closing of stomata are regulated by guard cells, which respond to environmental factors like light, water availability, and CO 2 concentration.

Answer 16

1. Water vapour evaporates out of the leaves via stomata. This is transpiration 2. More water will be pulled up through the xylem to replace the water that has been lost 3. More water is absorbed from the soil by osmosis 4. This constant movement of water through the xylem from the roots up to the leaves is known as the transpiration stream

B4 organising plants and animals Flashcards

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