2. Describe the concept of physiological homeostasis and illustrate it with one three examples from human organ systems.
3. Discuss the various sources of human stem cells, their characteristics, and potential for therapeutic use. What are some ethical concerns?
4. I am sitting here watching spring rituals play themselves out at my bird feeders. 1) One large male purple finch is "camping out" on the feeder and running everyone else off. 2) I hear a red bellied woodpecker drumming away on a dead tree snag in my front yard. 3) A Carolina wren is singing his heart out. 4) The male goldfinches are changing color daily, from the mossy greenish-yellow they sported all winter to a brilliant golden yellow, and 5) my cats are taking every bit of this in ...stalking constantly while the bravest birds scold and even seem to "dare" them (their belled collars pretty much dooms them to failure with all but the stupidest birds!)
Describe each of the behaviors 1-5 about in terms discussed in CH 26! The chapter is labeled Sex and Symmetry. The first section is how do innate and learned behaviors differ? The second is how do animals communicate? How do animals compete for resourses? How do animals find mates? What kind of Societies do animals form? And can Biology explain human behavior?
5. What are the impacts on ecosystems and issues with introduced, invasive and genetically-modified (GMO) organisms? Select one plant and one animal species to illustrate your points.
See the attached document, your questions are in bold. Good Luck!
1. Angiosperms put an enormous amount of energy into their fruits and flowers. Why? And why has this approach been so successful?
- Once plants became terrestrial organisms, they no longer had methods of protecting their seeds (especially from drying). The progeny of the plant resulting from the seed was the only method of ensuring that plant species would not die off, so a method needed to be developed into order to protect the seed, and therefore the species.
- Angiosperms developed flowers and fruits in order to protect the plants' seeds, and therefore future generations of the plant.
- In addition to protection of the seed, angiosperms use flowers and fruits for methods of reproduction. When plants were aquatic organisms they produced spores as a method for reproduction. When the plant released the spore, it could easily float away and grow in a different location. Land plants did not have that option often because seeds were too large and difficult to disperse.
- The development of the flower, and consequently the flower's parts, allowed land plants to spread into different ecological niches via insects, animals, and wind, much like the aquatic plants did using water. If flowers did not provide a significant benefit, the amount of energy used to create these structures might be a liability to the plant- we see multiple plants using flowers for reproduction today, so what does that say about the cost-benefit ratio?
- Also, flowers display major variations in form and structure, as well as display various characteristics unique to each plant species. Flowers are used as a marker of angiosperm species, and can signal to create evolutionary relationships between multiple angiosperm species.
- Some flowers even maintain mechanisms to prevent self-fertilization, leading to a greater genetic mix between plants, allowing for the most beneficial traits to be passed on and expressed. Generic variation is key to a species' survival.
- Fruits are an additional method of seed dispersal mostly dependent on animal ingestion and defecation.
- Not all terrestrial plants, usually the earliest evolutionarily, developed flowers, and they still use spores and cones as methods of reproduction.
- Flowers and fruits are beneficial to the plant in a way that evolves specific relationship with additional organisms. Flowers and fruits have allowed angiosperms to participate in a wide range of evolutionary relationships. In some cases, plants bearing fruits and flowers have relationships dependent on a specific animal (needed for seed dispersal and pollination). Often these relationships are beneficial to both the plant and the organism, leading to different levels of specialization.
- Angiosperms demonstrate how and why fruits and flowers are important to us daily; the creation of fruits and flowers requires a great deal of energy, yet plants from the past and plants today still use these mechanisms. Humans depend on the development of fruits and flowers for food- angiosperms are incredibly important in agriculture.
1. Sexual Reproduction in Angiosperms http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/Angiosperm.html
2. Angiosperms http://www.tolweb.org/Angiosperms/20646
3. Angiosperms Reproduction and ...
The expert examines angiosperms and energy investments in fruits and flowers.