For a flower to be pollinated, pollen from an anther (which is located at the top of the stamen) needs to reach a stigma (at the top of the pistle.) Some plants are genetically capable of pollinating themselves if their own pollen reaches their own stigma; some plants are not capable of self pollination under any circumstances.
For plants that can genetically self pollinate, but would prefer not to, they can avoid this by having their pistil and pollen/stamens mature at different times. If the stamens mature first, the pollen will be dispersed by animals or wind or whatever dispersal mechanism it relies on. Then by the time the pistil is ready to be pollinated, there is no pollen left in that flower to land on the stigma.
Answer:
The average (mean) time for her to wait is 7.5 minutes before the arrival of the next train.
Explanation:
The values between 4 and 11 minutes are: 5, 6, 7, 8, 9, and 10.
Since X has a uniform value between 4 and 11, then
average time = 
= 
= 7.5
The average time for Lexie to wait for the next train would be 7.5 minutes.
Answer:
do we have to choose 2 answers here?
Answer:
Explanation:
Machines simply make work easier to do. They increase the amount of force exerted on a body and also the distance through which the force is applied. Also, they can also change the direction through which force on them is applied in order to produce much more work.
Work done = force x distance
The input force in a machine is attenuated to yield even more force. This is the purpose of designing a simple machine. When the force increases, more work would be produce with our little effort applied on the body.
Work done is a function of the force applied on a body and the distance through which it moves.
