Plant Biology Flashcards
(31 cards)
What is the function of the root?
- Anchor the plant to the soil
- They penetrate deep into the soil, absorbing water and minerals
What is the function of the stem?
- They support the leaves flowers, fruits and buds
- It holds the leaf upright so it can trap the sunlight it needs for photosynthesis
What is the function of the leaves?
- It has a green chlorophyll found in chloroplast
- Chlorophyll helps to trap sunlight so the leaf can make food for the plant
What is the function of the flower?
- Reproductive part of the plant
- Carry out pollination and form fruits and seeds after fertilization
- They only appear certain times in the life cycle of a plant
What is Photosynthesis?
The process by which leaves in the presence of sunlight and chlorophyll use carbon dioxide and water to make glucose. Oxygen is released as a byproduct.
Word equation for photosynthesis?
Carbon Dioxide + Water ——-> Glucose + Oxygen
Simple Equation for photosynthesis
6CO² + 6H²0 —————> C⁶H¹²0⁶+ 60²
What is the process of photosynthesis?
Water is absorbed by the roots of plants through osmosis. Carbon dioxide is diffused into the plants through the stomata. Sunlight is absorbed by the leaf’s chloroplast.
Inside the leaf, the sunlight causes the water to seperate into hydrogen and oxygen. The hydrogen and carbon dioxide combine to form glucose. Oxygen is released as a byproduct.
(Water is oxidized, loses electrons and turns into oxygen and carbon dioxide is reduced and gains electrons and turns into glucose)
Factors affecting photosynthesis?
- Temperature- Photosynthesis requires enzymes to carry out the reaction. As these enzymes have an optimum temperature, photosynthesis also has an optimum temperature. This is usually 25’C
- CO2- Directly proportional
- Light intensity- Directly proportional
Storage of Glucose
- Starch and Lipids in seeds
- Transported to the Mitochondria to be used for plant respiration
- Glucose monomers join to form cellulose (carbohydrate) used to build or add strength to cell walls
- Glucose and nitrate ions join to form amino acids or proteins
Parts of the leaves:
Upper & Lower Epidermis
Cuticle
Palisade Mesophyll Cell
Spongy Mesophyll Cell
Vascular Bundle
Bundlesheath Cell
Xylem
Phloem
Guard Cells
Stomata
Function of Cuticle:
- Waxy Layer
- Protects from bacteria
- Prevents water loss
- Allows light to pass through
Function of Epidermis (Upper and Lower):
- Allows maximum light to pass through (Transparent)
- Protection
- Prevents excessive water loss
- Secretes waxy cuticle
- Does not have chloroplast
Palisade mesophyll vs Spongy mesophyll
Palisade mesophyll:
- Tall
- Tightly packed
- Contains chloroplast
Spongy mesophyll:
- Irregularly Shaped
- Air spaces in between for gas exchange
- Contains chloroplast
Function of Vascular Bundle
Contains transport tissue/conducting vessles
Bundle sheath cells
Conducts flow of water from xylem to the mesophyll cells and then to intermolecular spaces
Xylem function
Transports water and minerals
Phloem function
Transports nutrients and food
Guard cell function
- Regulates opening and closing of stomata
- Changes shape
- Protects
State the function of the stomata
Enables the diffusion of gases
Adaptation of Leaf
- Large Surface Area- Collect as much sunlight as possible
- Thin: Keep diffusion path short
- Leaf arrangement: To minimise overlapping and avoid shadowing of one leaf over another
Describe transport plants:
- Water is absorbed by the roots from the soil through the process of osmosis
- It is diffused into the root hair cells which have a large surface area to absorb more water
- From the root hair cells the water and minerals which are also absorbed by the root hair cells travel up the xylem in plants
- This water then is taken to palisade cells where it is used for the process of photosynthesis
- The excess water is then transported to the stomata in the plant where it evaporates into our surroundings as water vapour
Minerals needed in plants
Nitrates- Nitrates provide nitrogen which combines with glucose to form amino acids/proteins which help in growth
Potassium- Helps enzymes in respiration and photosynthesis
Phosphate- Along with helping in respiration and growth, they provide enzymes for DNA and Cell Membrane formation
Magnesium- Helps in formation for chlorophyll formation which is necessary for photosynthesis
Deficiency of minerals
Magnesium- Yellowing between veins of leaves
Nitrate- Stunted growth and yellowing of leaves
Potassium- Yellowing at tips and edges of leaves. Dead or yellow patches develop. Underdeveloped fruits and flowers
Phosphate- Leaves are darker than normal. Loss of leaves. Poor root growth
