Following general conditions are necessary for natural selection to occur in population:
- More organisms are born than can survive.
- Organisms vary in their characteristics, even within a species.
- Differences in reproduction and survival are due to variation among organisms.
According to Charles Darwin's theory of evolution by natural selection, organisms that possess heritable traits that enable them to better adapt to their environment compared with other members of their species will be more likely to survive, reproduce, and pass more of their genes on to the next generation.
Galapagos Finches: The Galapagos finches studied by Darwin on his famous voyage are probably the most common example of natural selection.
Basically the seed contains 2 parts, the testa, which is the seed coat that protects the seed and cotelydon, which is the inside of the seed, containing the radical and plumle.
for seed to germinate, we need 3 basic conditions,
warmth, it is the suitable temperature for seed germination, it can influence the activity of enzymes. providing a optimum temperature
water, to soften down the testa so that the shoot can break out from the testa
and oxygen, for aerobic respiration
.
If these conditions are absent, the seed may be in the state of dormancy. where is won't germinate until it meets the suitable conduction.
after that, the enzyme will digest the nutrient inside the seed and provide amino acid, which is necessary to seed germination. and meanwhile the aerobic respiration provides energy, so that the plumlecan shoot out, and be the shoot of the plant.
and then until it grows leaves, it'll start to complete photosynthesis, instead of using the nutrients inside the cotelydon.
