Plants Flashcards
Function of epidermal tissues
It is a protective tissue that covers the entire surface of the plant. the epidermis protects the plant from the infection and water loss
Function of palisade mesophyll
For photosynthesis. The cells in here are packed tightly together and contain chloroplasts to maximize energy production during photosynthesis
Function of spongy mesophyll
Allows for the interchange of gases (Co2) that are need for photosynthesis
Function of xylem
It transports water from the roots to the stems and leaves, but it also transports nutrients. Also provides mechanical support and storage
Function of phloem
It moves food substances that the plant has produced by photosynthesis to where they are needed for processes.
Function of meristem tissue
A meristem is a collection of undifferentiated cells that can divide and become other specialized types of cells in the plant. Meristem tissue is important because it allows for plants to grow and repair damaged tissue
Structure of the root
In the root, the xylem forms a central column. It forms a solid support. The phloem is towards the centre, outside the xylem
Function of the root
Roots absorb water and nutrients from the soil. They anchor the plant firmly. They help in storing food and nutrients. Roots transport water and minerals to the plant
How are root hair cells adapted to their function
Root hair cells have a very large surface area due to them being very long and having hair like projections. This allows more active transport of mineral ions to take place so the plant is able to take in as many important mineral ions as possible
Effects of factors on the rate of transpiration
Several factors can affect the rate of transpiration, including temperature, humidity, air movement, and light intensity. Warmer temperatures generally lead to higher transpiration rates, while higher humidity levels decrease the rate of water loss.
How does a potometer work
As water is
transpired
from the leaves, the shoot absorbs water from the potometer.
The distance the air bubble moves in a certain period of time can be used to calculate the rate of water uptake.
The apparatus is set up under water to prevent the entry of any unwanted air bubbles.
Effect of wind on on the rate of transpiration
The faster the wind speed, the higher the rate of transpiration. This is because the movement of air across the surface of leaves causes evaporation of water from the mesophyll cells, and this loss of water must be replaced by water moving up the xylem vessels from the roots.
Effect of humidity on the rate of transpiration
The higher the humidity, the lower the rate of transpiration as there is a lower concentration gradient so less evaporation
Effect of temperature on the rate of transpiration
The higher the temperature, the faster the rate of transpiration as the particles have more kinetic energy so faster moving particles escape more easily
Effect of light on the rate of transpiration
The higher the light intensity, the faster the rate of transpiration as light opens up the stomata.
Role of guard cells
Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata
Role of stomata
Stomata regulate gas exchange between the plant and environment and control of water loss by changing the size of the stomatal pore
What is translocation and how are sugars transported around the plant
Translocation is the movement of materials in plants from the leaves to other parts of the plant. Nutrients, mainly sugars, are created in the leaves during photosynthesis. These are then transported throughout the plant through phloem, which are a long series of connected cells.
Role of phloem tissue in translocation
Phloem tissue transports organic substances in plants. These organic substances include sugars, such as sucrose, and some minerals.
Explain physical plant defence adaptations
Cellulose wall form a physical barrier between the cells and the pathogens, protecting it from infection
Explain chemical plant defence adaptations
Produce compounds that have anti-microbial properties that can defend the plant from disease causing agents.
Explain mechanical plant defence adaptations
A impenetrable barrier of bark and waxy cuticle. Others include hard shells thorns and spines.
What is tobacco mosaic virus
Infects tobacco through contact with other plants(either naturally or by the hands of the farmers). It infects the chloroplasts and turns it from green to a yellow/white mosaic pattern. This reduces the plants ability to photosynthesize and grow properly. There is no cure for this disease.
What is rose black spot
Caused by a fungus that which infects roses and causes black/purple spots on the leaves. Reduces the plants ability to photosynthesize. Transmitted through the air of the water and also through contact of gardeners.
Define a tropism
A tropism is a growth in a plant in response to a stimulus. The stimulus could be a change in the direction of light or a water source
