<h2>Asteroid impact and Dinosaur extinction. </h2>
Explanation:
The scientists suggest that when a sufficiently large asteroid or comet struck the earth surface, they might have caused dust particles to rise up in the atmosphere and form a thick covering on the earth blocking the sun rays.
The blocking of sun rays must have resulted in severe colds and plants failed to carry out photosynthesis. Since, the plant died out , the herbivores got extinct because of the lack of food.
The loss of herbivores resulted in shortage of food for carnivores, and the larger carnivores started feeding on the younger population of their own species. Day by day the population size diminished and the dinosaurs along with some other species of plants and animals got extinct.
The f1 generation may have genes for short plants just that the genes for long plants are dominant over the genes for short plants(recessive) so when cross pollination happen and that two f1 long plants which are homozygous cross pollinate, the recessive genes have a chance of being paired up in new offspring(F2 offspring) thus the possiblity of short plants in f2 generation
Fertilizer is added to soils to increase plant productivity. A common type of fertilizer is called NPK fertilizer because of its ingredients: nitrogen (N), phosphorus (P), and potassium (K).
