Gymnosperm

II. Nature is not a Museum The gymnosperms are often called ‘Living Fossils’, or are dismissed as being primitive. Gymnosperms are indeed ancient: originating in the carboniferous period (Bowe, Coat, & dePamphilis, 2000). They can be divided into four monophyletic groups: ginkophytes, gnetophytes, cycads, and the largest of the four (with more than 600 extant species), conifers. Conifers account for the greatest diversity amongst the gymnosperms. This diversity might pale in comparison to that of the angiosperms, but a group can have biological importance without being speciose. From an ecological point of view, gymnosperm success is in fact comparable to angiosperms, as gymnosperms are thriving in important niches across latitudes. This is…

the best competitors, and angiosperms have certainly been described as having an extra edge. As discussed in the introduction, the fossil record shows that gymnosperms were quickly displaced by angiosperms upon their arrival. Yet despite the number of hypotheses (table 1) put forward to explain this shift in vegetation, gymnosperms’ competitors have not yet been discovered. Among the numerous hypotheses, three are discussed in depth here (summarised in fig. 1). The first two hypotheses are…

Plant Growth Lab The world is full of variety of species that help make the Earth a unique place to live in. Many of the species that live on Earth are plants. Plants can be Bryophytes or Tracheophytes. Bryophytes are non vascular and lack roots, stems and leaves. Tracheophytes can be spore producing or seed producing. Seed producing Tracheophytes can be Gymnosperms or Angiosperms. Gymnosperms have seeds that are enclosed in a cone and would include Pines and Coniferous trees. Angiosperms…

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…

revealed the random movement to be a general property of matter in the state, and the phenomenon has long been know as Brownian motion in his honor” (Britannica 2). Scientists extensively misunderstood Brown’s discovery of the Brownian motion. Scientists had asserted that Brown did not have the correct microscope needed to prove such a theory. “It has become plain that many workers have discussed the problem without consulting Brown’s original words on the subject, and it is abundantly clear…

characteristics were fewer bones in the skull and enlarged lower jawbones. Scientist think that Therapsids “were endothermic or warm blooded, enabling the to maintain a constant internal body temperature.” (Chapter 13) this helps them expand any habitats. But everything was about to be exterminated. The event of Permian-Triassic exterminated 79 percent of the life on land. this would include the pareiasaurs, reptiles, dinocephalian and many more. over 96 percent of the marine species. The…

found in most island ecosystems where there is a strong wind direction. Hawaii is a great example. The islands of Waikiki and Diamond Head receive only about 13 inches of rain a year nearly a desert! Boreal Forest The boreal forest is found in a nearly continuous abundance across North America and Eurasia. The boreal forest corresponds with regions such as the subarctic and cold continental climate. There are long, severe winters with temperatures as low as freezing and very short summers. (50…

root and the stem. The crown gall is a neoplastic disease of plants caused by Aqrobacterium. The interest in the bacteria stems from its relevance to the cancer problem, that animal and plant cancer have many common characteristics. The disease it induces provides investigators with a model system in which fundamental aspects of bacterial infection, host-parasite relationships as well as tumour etiology may be extensively explored. Crown gall has been reported to be a widespread disease in fruit…

the arthropods, and the Late Devonian Mass Extinction destroyed all but one of the remaining trilobite families (Proetida), which was wiped out in the End-Permian Mass Extinction. Survivors Gymnosperms Gymnospermae At the beginning of the Permian period, the dense, marshy lycopod (plants that reproduce with spores; asexual reproduction) forests of the Carboniferous were still intact and provided a habitat for much of the land life of Pangaea. However, as the Early Permian gave way to the…

effects of having various amounts of vegetation grow caused the decrease of carbon dioxide levels. Also the predatory species Amphibians were growing in size and diversity, the species resembled modern day crocodiles. The climate at the time was humid and hot and had a vast amount of plant life. The sixth and final period was the Permian Period during this period there was the biggest mast extinction to ever come. The climate went through extreme conditions. The supercontinent of Pangea had…