Jr2 Chp 1 Plants

• Definition of Photosynthesis

  When light is absorbed by green plants, the light energy is used to synthesis 合成 organic compounds, such as glucose from water and carbon dioxide.
• Photosynthesis is the process by which green plants make their own food (synthesize organic compound 合成有机物) such as (1) and (2) by using (3) in the presence of (4)

  1. carbon dioxide

  2. water

  3. light energy

  4. chlorophyll
• Physiological activities of plants

  植物的生理活动

  1. Photosynthesis 光合作用

  2. Transpiration 蒸散作用

  3. Respiration 呼吸作用
• Green plants perform（）in which they are able to synthesize food through the process of photosynthesis.

  autotrophic nutrition 自生营养
• raw materials , products and conditions of photosynthesis

  Raw materials

  1. carbon dioxide

  2. oxygen

  
  

  Products

  1. glucose

  2. oxygen

  
  

  Conditions

  1. sunlight (as light energy)

  2. chlorophyll
• Word equation for photosynthesis

  Chemical equation for photosynthesis

  word equation

  carbon dioxide + water — sunlight & chlorophyll—>glucose + oxygen

  
  

  chemical equation

  6CO2 + 6H2O — sunlight & chlorophyll—>C6H12O6 + 6O2
• Photosynthesis is a type of (1 ).

  (2) is synthesized from carbon dioxide and water while energy is absorbed.

  1. anabolism 合成作用

  2. glucose
• Energy change involved in photosynthesis

  light energy to chemical energy.

  以食物存在的能量
• 1. The organ that is used to carry out photosynthesis is

  2. The cells that carry out photosynthesis are known as

  3. Structure that carry out photosynthesis is

  1. leaf

  2. Cell = mesophyll 叶肉细胞

  3. Structure = chloroplast
• 会影响光合作用的因素

  1. 二氧化碳

  2. 水

  3. 阳光

  4. 叶绿素
• Factors affecting photosynthesis

  1. carbon dioxide

  2. sunlight

  3. water

  4. chlorophyll
• 1. Light energy is absorbed by the () in the leaves.

  2. Carbon dioxide from the air enters the leaves through ()

  3. () is released into the air during photosynthesis as a () 副产品

  4. Water is absorbed by the ()

  1. chlorophyll

  2. stoma (singular) stomata (plural) 气孔 (叶片下面)

  3. Oxygen, by-product 副产品

  4. roots

  **roos cannot carry out photosynthesis, but only respiration
• The glucose synthesised during photosynthesis can be converted into other form of carbohydrates such as (1) that can be stored in (2)

  1. starch

  2. plants 果实
• List out all the leaf structure

  1. cuticle 角质层

  2. upper epidermis 上表皮

  3. palisade mesophyll 栅栏叶肉细胞

  4. spongy mesophyll 海绵叶肉细胞

  5. air sac / air space 气室

  6. vascular bundle 维管束/运输导管

  -xylem 木质部/木质导管（中间）

  -phloem 韧皮部/韧皮筛管（外面）

  7. lower epidermis 下表皮

  8. stoma 气孔

  9. guard cell 保卫细胞

  
• Each epidermis consist of a layer of (1) , without (2)

  1. epidermal cell

  2. chlorophyll
• Characteristic of upper epidermis

  1. no chlorophyll

  2. transparent to visible light / transparent to allow light pass through
• Function of upper epidermis

  1. Protect the underlying cells from injuries/damage

  2. Prevent loss of water
• Characteristic of cuticle

  1. waxy

  2. transparent

  3. waterproof
• Functions of cuticle(3)

  1. Reduces excessive water loss through evaporation

  2. Enable the leaf to trap sunlight

  3. Protects the leaf
• How palisade mesophyll tissue arranged? And why would they arranged like that?

  Palisade mesophyll tissues are arranged vertically and closely packed (below the upper epidermis). ----enable the cells to obtain maximum sunlight
• Characteristic of palisade mesophyll

  1. each cell contains largest number of chloroplasts

  2. major site of photosynthesis (since it has largest number of chloroplast)
• Function of palisade mesophyll

  1. absorbs sunlight
• Characteristic of spongy mesophyll

  1. irregular in shape & arranged loosely
• Function of spongy mesophyll

  1. allows diffusion of water and gasses through leaves
• How spongy mesophyll are arranged?

  Spongy mesophyll are loosely arranged with many large air spaces between the cells.
• Function of air space/air sac in spongy mesophyll

  Large air space/air sac facilitate促进 the diffusion of carbon dioxide and oxygen between the cells of the leaf.
• Characteristic of lower epidermis

  1. consists of one layer of cells

  2. transparent to visible light / transparent to allow light pass through

  3. no chloroplast
• Function of lower epidermis

  1. protects against water loss and the leaf from damage

  2. maintains the shape of leaves
• Vascular bundle are located in

  the vein of the leaves.
• Vascular bundle consists of 2 tissues. What are they and what are their functions?

  1. xylem

  -transport water and mineral salts (nitrogen) from the soils to the leaves

  2. phloem

  -transport dissolved organic substances /the products of photosynthesis from the leaves to all part of the plant
• What made up of xylem and phloem?

  1. xylem

  - made up of long, capillary tubes 毛细管

  2. phloem

  - made up of cylindrical cells
• Function of stoma


  1. allows gaseous exchange between leaf and the atmosphere

  2. excess water evaporates through stoma

  **carbon dioxide enters the leaf, while oxygen exit the leaf through stoma

  **Stoma is a HOLE, not a STURCTURE
• Characteristic of guard cell

  1. a pair of epidermal cells which contain chloroplast
• Function of guard cell

  1. control opening and closure of stomatal pores
• Characteristic of lamina

  1. thin and flat

  2. expanded portion of a leaf

  -to increase the surface area for more sunlight to be absorbed by chloroplasts, driving the rate of photosynthesis upward.

  增加表面积，让更多的阳光被叶绿体吸收，从而提高光合作用的速率。

  3. translucent to visible light
• 1. Xylem is dead/living cell.

  2. Phloem is dead/living cell.

  1. dead cell

  2. living cell
• In lamina, vein is a ___1___. The tissue is___2___.

  1. structure

  2. vascular bundle- xylem and phloem
• Where water come out from?

  Xylem. Xylem transport water from the soil to leaf.
• Phloem transport the products of photosynthesis from the leaves to all part of the plant. What are the products?

  1. glucose

  2. starch (for store)

  3. hormone
• Why is the front side of the leaf（叶子的正面）has s darker green than the other side of the leaf（叶子的反面）?

  The front side of the leaf have palisade mesophyll that contains major site of chloroplast that enable to carry out photosynthesis. Besides that, the front side of the leaf is where it absorb the sunlight for photosynthesis so it must have more chloroplast than the other side of the leaf.