The x-axis shows the relative
amount of DNA per cell thought not directly. This can be seen through a
histogram a specific type of a graph. Looking at the bars of the histogram you
can follow peaks and dips which correspond to something like fluorescence which
indirectly shows the relative amount of DNA in cell.
D. controlled cell suicide
Habitats of the plants:
X : winter or cold mountainous habitat
Y : desert habitat
Z: Aquatic habitat
Explanation:
The X plant leave morphology suggests that thick wax coating of leaf helps it to retain water in it. Such plants are called conifers. They are not shed every year so suitable for sunlight to be captured for photosynthesis. In cold regions heavy wind happens cone like leaf is able to resist the winds and prevent it from falling. The cone like structure of leaves help them let the snowfall.
The plant Y leaves and root morphology suggests that it is well suited for dry lands or desert as where less water is there. They store water for longer time when it rains because of the extensive root system. The spine leaves help in reduced transpiration as water scarcity is there.
The plant Z leaves morphology suggests that thin and ribbon structure leaves can help them resist the pressures of flowing water as there are air space in the leaves which provide buoyancy to the leaves.
Lets consider the water drop as being part of the water in a lake. The water droplet evaporates and changes from a liquid state to a vapor state by gaining energy and travels up to the upper atmosphere. In the atmosphere the water droplet once again condenses in the clouds and is stored until it can be precipitated on to the land again in the form of rain or other forms of precipitation.
