Answer:
Option D
Explanation:
Options for the question
A)import seeds produced in the southern hemisphere.
B)plant the flowers out-of doors in november.
C)keep the plants in a warm growing environment.
D)expose the plants to an hour of light in the middle of each night until the end of april.
Solution
Since Chrysanthemum is a short-day plant, its flower mainly develop during night and hence they require long nights of 11 to 12 hours. Blackout system is sometimes used to induce flowering.Flowering can be delayed by regulating both light and temperature. this is done by exposing plants for a short period of time to light (can be artificial) and to some source of heat that produces 85° F or higher temperature.
Thus if flowers are required in month of may, flowering can be delayed by exposing Chrysanthemums plant to light and heat source during night time
Option D is correct
Electromagnets can easily be turned on and off.
Explanation:
An electromagnet produces magnetic field which is done by the electric current. These electromagnets contain a wire would like a coil. The current passes through the wire and the magnetic field is concentrated in the center which is the "center of the coil".
When the current is "turned off" the magnetic field "disappears". This shows that we have can have a control over the passage of current or the magnetic field. Thus, the "main advantage" of the electromagnet is that it can be easily turned on and off whenever necessary.
It belongs to the Consumers group
Answer:
lack of oxygen
Explanation:
Just like us humans, plants also need oxygen to live
