Do you ever wonder what a seed – generally small and having negligible demands from the environment – is capable of? How, with time, plant seeds have overcome the need to depend on water for their reproductive needs? If yes, then this article has all the answers to your question why did seed production help plants move to land.
Many people don’t know that 500 million years ago, plants in their early stages of life were dependent on water for their reproduction process. The dispersal of their pollen, the process of fertilization, the structural stability, the maintenance of moisture, and the survival of the embryo; everything was conditional to the need for water.
Keep on reading if you want to find out the exact science behind why did seed production help plants move to land.
A seed is a product of a ripened ovule as a result of fertilization, which is covered in a seed coat with some stored food. It contains the genetic wisdom of a plant and the capacity to reproduce, in addition to the characteristic to remain dormant until favorable conditions arrive.
Seeds have played an important part in ecological restoration, which was previously halted due to primitive plants like ferns, mosses, and liverworts, which do not have seeds and require water-dependent means to propagate themselves.
The production process of seeds is highly variable in each plant type due to their distinctive characteristics, weather variations, the presence of insects and diseases, and internal plant cycles.
In the seed plants, the female gametophyte consists of the egg and some supportive cells, including the endosperm-producing cell that will support the growth of the embryo. The diploid zygote is produced as a result of the fertilization of the egg.
Seeds are produced in related plant groups and their manner of production distinguishes them from others. Angiosperm seeds or enclosed seeds are produced in a hard and fleshy structure called a fruit that encloses the seed for secure and healthy growth.
On the other hand, seeds of gymnosperms, commonly known as naked seeds, have no special structure to enclose the seeds, except it is covered with cone scales in some conifers.
Plants that are enriched with nitrogen, phosphorus, and potassium generally produce seeds that are bigger as compared to unfertilized plants. The enlargement of size is due to nutritional availability.
Water availability promotes seed production and the development of seeds. The deficit water level has a negative impact on seed production, which results in a reduced number of seeds.
An optimum level of temperature is required by the plant for maximum seed production. Higher than normal temperatures can cause forced maturation while lower temperatures can cause retarded seed development.
Seed production and development rate can be affected by the positioning of seeds on the plant. Problems like inadequate photosynthetic supply and slower growth rates are common.
Seed dispersal is the movement and transfer of seeds away from the parent plant for germination and reproduction. Plants have limited mobility and they rely on various biotic and abiotic factors for their transmission.
Abiotic factors include wind, water, gravity, etc. while biotic include birds and animals. Some plants are serotinous and disperse only as a result of an environmental stimulus.
Seed dispersal helps plants to reach specific habitats that are favorable for their survival and reproduction. It also helps colonize vacant habitats and promotes ecological restoration.
Why Did Seed Production Help Plants Move to Land
The answer to the question of why did seed production help plants move to land focuses primarily on the adaptations of seeds to land. Following are some of the distinctive features of seeds:
Unlike primitive plants having haploid cells which make them water-dependent, seeds contain a diploid embryo which facilitates germination to produce a sporophyte that makes them adaptive to land conditions.
The protective coat present on the outer side of the seed gives them a superior evolutionary advantage and a large number of layers present on the inner side prevent desiccation, making plant reproduction independent from the need for water.
500 million years ago, the first plants to colonize land were bryophytes followed by liverworts and primitive vascular plants called pterophytes which were dependent on water for the completion of their life cycle. The core strand that distinguishes bryophytes and pterophytes from gymnosperm and angiosperms is the requirement of water for reproduction.
Seed dormancy is an evolutionary adaptation that helps seeds to survive in harsh and unsuitable environmental conditions until favorable conditions for the plant to germinate arrive. It increases the probability of seedling survival.
The main purposes of dormancy include prevention of immediate germination, survival of seed in unfavorable conditions, and giving enough time for dispersing agents to act.
A thick waxy cuticle is present on the outer surface of plant leaves which prevents evaporation by increasing water retention. This layer also prevents the plant from damaging due by UV rays.
The land plant has cell structures in the epidermis of plant leaves called stomatal openings through which the exchange of water and carbon dioxide between the plant cells and the environment takes place.
Land plants have developed a root system that is majorly involved in anchoring the plant and in addition to that helps in the absorption of water and minerals.
This article gives you the most relevant reasons why did seed production help plants move to land. The evolution of seeds and adaptation of new and distinctive features over time has resulted in a remarkable transition for plants.
Whether scattered by the wind, transmitted by water, or carried by animals, seeds in the present times have scattered all over the geographic range. Therefore, our focus should be on methods of plant propagation, maximization of fertilization, seed development, and seed dispersal, so the photosynthetic organisms can be multiplied.