Who’s the better reproducer?
With time comes change and with change comes evolution. Organisms are classified into three distinctive groupings: Bacteria, Archea, and Eukarya and the kingdom of plants (Plantae) falls under Eukarya. It could be argued that plants are one of the most valued organisms on Earth. Not only do they provide oxygen for the oxygen dependant organisms, such as mammals through the process of photosynthesis, but, they also provide stable conditions and habitats for other organisms by stabilizing the soil and much more. It is said that organisms within kingdom Plantae evolved from the sea. More specifically, green algae charophytes to what we know as our land plants. There are two specific clades within charophyta: …show more content…
Gymnosperms are the naked bearing seeds (e.g conifers, cyadas etc.) that thrived as the climate dried, differentiating them from bryophytes and non-vascular seedless plants. In the late Mesozoic era, around 140 million years ago, angiosperms began to replace gymnosperms in certain ecosystems. Angiosperms are seeds of flowering and fruit-bearing plants and have a intricate life cycle. Within the diploid megasporangium of each ovule the diploid megasporocyte will meiotically divide into four haploid megaspores. Only one of the four megaspores will survive and that will become the female gametophyte. Within the anther are microsporangium that contain many diploid microsporocytes. The microsporocytes will meiotically divide into haploid microspores that will flourish into pollen grains. The generative cell will divide into two sperms and the tube cell will produce the pollen tube. Either by wind or a pollinator, pollen grains are carried to the sticky stigma of the ovary and sperm burrow their way down to the ovules. One sperm will fertilize the ova, becoming the zygote, and the other will fuse with the central cell and become the triploid endosperm nucleus. The zygote further develops into the embryo that is surrounded by the endosperm that is encased in a diploid seed coat. The ovary will then swell into the fruiting …show more content…
For example, seed-bearing plants have many ways of pollination whereas, spores have a singular dispersal method. The terminal sac that rests upon the end of the filament stalk, the anther, contains the pollen grains. Those pollen grains can be dispersed either by a bump of a insect or even by hitchhiking on a simple breeze. Whereas spore-producing plant have to rely solely on a gust of wind. Angiosperms also possess multiple protective and defensive structures that bryophytes lack. Flower petals, sepals, and in some flowering plants, thorns work protect the precious ovary from potential ingestion by an animal. Bryophytes do not have any protective mechanisms however, their spores can mass pollinate and are not limited like that of a flower ovary being that only six ovules per flower can be pollinated. The minimization of the gametophytes in seed-bearing plants now grants the paternal sporophyte the ability to protect the gametophytes from many stressful environmental conditions such as detrimental amounts of UV rays and
With time comes change and with change comes evolution. Organisms are classified into three distinctive groupings: Bacteria, Archea, and Eukarya and the kingdom of plants (Plantae) falls under Eukarya. It could be argued that plants are one of the most valued organisms on Earth. Not only do they provide oxygen for the oxygen dependant organisms, such as mammals through the process of photosynthesis, but, they also provide stable conditions and habitats for other organisms by stabilizing the soil and much more. It is said that organisms within kingdom Plantae evolved from the sea. More specifically, green algae charophytes to what we know as our land plants. There are two specific clades within charophyta: …show more content…
Gymnosperms are the naked bearing seeds (e.g conifers, cyadas etc.) that thrived as the climate dried, differentiating them from bryophytes and non-vascular seedless plants. In the late Mesozoic era, around 140 million years ago, angiosperms began to replace gymnosperms in certain ecosystems. Angiosperms are seeds of flowering and fruit-bearing plants and have a intricate life cycle. Within the diploid megasporangium of each ovule the diploid megasporocyte will meiotically divide into four haploid megaspores. Only one of the four megaspores will survive and that will become the female gametophyte. Within the anther are microsporangium that contain many diploid microsporocytes. The microsporocytes will meiotically divide into haploid microspores that will flourish into pollen grains. The generative cell will divide into two sperms and the tube cell will produce the pollen tube. Either by wind or a pollinator, pollen grains are carried to the sticky stigma of the ovary and sperm burrow their way down to the ovules. One sperm will fertilize the ova, becoming the zygote, and the other will fuse with the central cell and become the triploid endosperm nucleus. The zygote further develops into the embryo that is surrounded by the endosperm that is encased in a diploid seed coat. The ovary will then swell into the fruiting …show more content…
For example, seed-bearing plants have many ways of pollination whereas, spores have a singular dispersal method. The terminal sac that rests upon the end of the filament stalk, the anther, contains the pollen grains. Those pollen grains can be dispersed either by a bump of a insect or even by hitchhiking on a simple breeze. Whereas spore-producing plant have to rely solely on a gust of wind. Angiosperms also possess multiple protective and defensive structures that bryophytes lack. Flower petals, sepals, and in some flowering plants, thorns work protect the precious ovary from potential ingestion by an animal. Bryophytes do not have any protective mechanisms however, their spores can mass pollinate and are not limited like that of a flower ovary being that only six ovules per flower can be pollinated. The minimization of the gametophytes in seed-bearing plants now grants the paternal sporophyte the ability to protect the gametophytes from many stressful environmental conditions such as detrimental amounts of UV rays and