seedless plants

2. grain each of the microscopic particles, typically single cells, of which pollen is composed.
6. the transfer of pollen to a stigma, ovule, flower, or plant to allow fertilization.
7. the male fertilizing organ of a flower, typically consisting of a pollen-containing anther and a filament.
8. an unborn or unhatched offspring in the process of development, in particular a human offspring during the period from approximately the second to the eighth week after fertilization (after which it is usually termed a fetus).
9. the female organs of a flower, comprising the stigma, style, and ovary.
12. a small or immature ovum.
13. the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water.
15. a female reproductive organ in which ova or eggs are produced, present in humans and other vertebrates as a pair.

1. respiration Cellular respiration is the process through which cells convert sugars into energy.
3. of generations a pattern of reproduction occurring in the life cycles of many lower plants and some invertebrates, involving a regular alternation between two distinct forms.
4. the response of an organism to seasonal changes in day length.
5. a flowering plant's unit of reproduction, capable of developing into another such plant.
6. hormone Any of various hormones produced by plants that control or regulate germination, growth, metabolism, or other physiological activities.
7. a thing or event that evokes a specific functional reaction in an organ or tissue.
10. the sweet and fleshy product of a tree or other plant that contains seed and can be eaten as food.
11. the turning of all or part of an organism in a particular direction in response to an external stimulus.
14. a minute, typically one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion, characteristic of lower plants, fungi, and protozoans.