Advertisements
Advertisements
प्रश्न
Explain how harmful chemicals enter our bodies.
उत्तर
Chemical substances such as pesticides are sprayed over crop plants to protect them from pests and diseases. When herbivorous animals eat plant food, these poisonous chemical pesticides go into their bodies. Man, being an omnivore, eats plant food as well as the flesh of herbivores. Thus, the pesticides present in plant food and in the bodies of herbivores are transferred to the bodies of humans through food. In this way, harmful chemicals enter our bodies.
APPEARS IN
संबंधित प्रश्न
We do not clean natural ponds or lakes but an aquarium needs to be cleaned regularly. Why is it so ? Explain.
The following statement is true or false :
In biology, human beings are called producers.
Which organisms belong to third and fourth trophic levels in the food chain comprising the following?
Rats, Plants, Hawk, Snakes
Which of the following represents a possible food chain found in a pond :
Primary producers |
Primary consumers | Secondary consumers |
(a) green algae | fish | mosquito larvae |
(b) fish | green algae | mosquito larvae |
(c) mosquito larvae | fish | green algae |
(d) green algae | mosquito larvae | fish |
A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y
What could be X?
A food chain occurring in the sea which provides food for many people can be written as :
phytoplankton → zooplankton → X → Y
Name the organism which Y could be.
What would happen to the number of rabbits and grass plants if the number of foxes decreased?
Observe the food web and answer the questions given below:
Why do all food chains start with plants?
In a food chain grasshopper gets energy by eating frog.
Which statement is correct with respect to the food chain?