What are the methods used by plants to get rid of excretory products?
Excretion is process where all waste material and the excess amount of water, minerals and salts are excreted out through the life processes which are involved by the plants as well as by the animals. In plants various methods are used to get rid of excretory products.
Through stomata:- when the process photosynthesis occurs, in which plants make their food by their own with the help of sun’s energy. This process releases oxygen by consuming carbon dioxide from the environment and also releases their end products in the environment through the stomata, therefore it helps in the exchange of gases.
Through evaporation or transpiration:- the amount of water, minerals and salts are excreted out through stomata.
Some other waste removed with the dead cells when plant loses some of their leaves or some waste are stored in the vacuoles which are resins and gums are excreted out.
Wastes products as resins and gums are present in the old part of the xylem which are also get excreted.
Some wastes product can be excreted into the soil or through petals, fruits etc.
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
How is the amount of urine produced regulated?
What criteria do we use to decide whether something is alive?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm. (c) chloroplast.
(b) mitochondria. (d) nucleus.
What are the differences between autotrophic nutrition and heterotrophic nutrition?
What are outside raw materials used for by an organism?
What would be the consequences of a deficiency of haemoglobin in our bodies?
What are the components of the transport system in highly organised plants?
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
What kind of mirror – concave, convex or plain – would be best suited for use in a solar cooker? Why?
An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image.
The magnification produced by a plane mirror is +1. What does this mean?
Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
Why does the cord of an electric heater not glow while the heating element does?
Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 106 Ω, (b) 1 Ω and 103 Ω, and 106 Ω.
What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series?
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –
(a) 100 W (b) 75 W (c) 50 W (d) 25 W
Name a device that helps to maintain a potential difference across a conductor.