Question

 

1. Why do scientists think that double fertilization is advantageous to angiosperms?

2. How can animals have a negative impact on angiosperm reproduction?

3. How can animals benefit angiosperm reproduction?

4. Which type of symmetry provides for greater specificity of pollen transfer, and why?

5. Describe two strategies that promote cross-pollination

Answer 1

1.The main aim of double fertilisation is energy conservation.Egg is nurtured by endosperm only after fertilisation.The ability of angiosperm in survival and success is mostly because of this double fertilisation.Reason for their abundance in earth today is because of this double fertilisation.

2. pollination one factor,herbivory another..but because of the survival strategy this plants are tradeoff between offspring size and number.Difference in seed size. increased competition generally selects for larger offspring size,but size dependent predation leads to smaller or larger offspring.

3. pollination.some animals help in reproduction by eating the fruit including its seeds. digested seeds are then dispersed and eventually germinate and grow into new plants.some seeds not germinate until they are digested.

4.zygomorphic flowers are more complex and need specific pollinators.Horizontal flower orientation in zygomorphic flowers helps in pollinators recognition and landing effective ness.