Sporophyte generation - It is found in both seed and seedless plant. Dominant phase of the life cycle of the seedless plants is diploid sporophyte while in seed plant male and female gametes fuses to produces a diploid zygote which develops into a sporophyte.
Pollination - It occurs in seed plants only
Sporophyte contains male and female reproductive structures - It is found in both seed and seedless plant.
Single fertilization - It occurs in both seed and seedless plant
Sperm cells transported by water to egg cells - seedless plant only
You could say DNA is found in both viruses and in living single-celled organisms because DNA is necessary to replicate itself.
Answer: The oxygen content at the source of the streams or rivers is higher as compared to the mouth of the river. Consequently, the organisms which require more oxygen tend to find at the source of the rivers whereas the organisms which require less oxygen tend to find at the mouth of the river.
Explanation: