An ecologist studying plants in the desert performed the following experiment. She staked out two identical plots, which included a few sagebrush plants and numerous small, annual wildflowers. She found the same five wildflower species in roughly equal numbers on both plots. She then enclosed one of the plots with a fence to keep out kangaroo rats, the most common grain-eaters of the area. After two years, to her surprise, four of the wildflower species were no longer present in the fenced plot, but one species had increased dramatically. The control plot had not changed. Using the principles of ecology, propose a hypothesis to explain her results.
Explanation:
- This example highlights the impact of plant predation on species selection. In the fenced off plot animal predation is not a factor on plant selection.
- In this case plants will compete for resources only with each other and in this case one plant had a selective advantage over the other 3 species of plants. In the plot exposed to animal predation the ratio of the four species is equal.
- This is likely do to an increased preference of animals for the plant species that dominates in the fenced off plot and/or anti-animal predation tactics by the other three species.
a.Hypothesis: kangaroo rats are keystone species
-Reintroduce kangaroo rats (and the other locally extinct species)
-Should observe equilibrium re-established
b.Hypothesis: kangaroo rats exert top-down control on community
-Reintroduce kangaroo rats (and other locally extinct species)
-Increase kangaroo rat population in other plot
-Decrease (but don't eliminate) kangaroo rat population in other plot
c.Hypothesis: Locally extinct species inferiorly competed with the extant species of plant
-Remove surviving species from other plot (and remove kangaroo rat population)
Answer:
A duck's foot is webbed and the chicken's foot is not
Explanation:
The difference is due to apoptosis.Ducks have webbed feet because the cells between their toes do not undergo apoptosis
Answer:
C) generally consist of 1,000 different substances
Explanation:
Metabolites are compounds, usually organic, that participate in the chemical reactions that take place at the cellular level. The set of these biochemical reactions, together with the intracellular physical-chemical processes, constitutes the cellular metabolism, the molecular basis of life. The metabolism includes the degradation of molecules for obtaining energy (catabolism) and the synthesis of molecules necessary for growth, reproduction and repair (anabolism).
The succession of metabolic reactions that transform a given initial substance into another is known as a metabolic pathway. The starting substance is known as a substrate or raw material. The final substance is usually known as the final product or metabolite (a metabolic pathway can generate several final products) and the intermediate substances as intermediate metabolites. An intermediate or final metabolite in one metabolic pathway may be the substrate in another, which makes the vast majority of metabolic pathways interconnected.
Metabolites can be classified into two large groups, primary and secondary. Primary metabolites are defined as those that are directly involved in the normal growth, development and reproduction of an organism with an important physiological function. On the contrary, secondary metabolites are not directly involved in these processes. The absence of a primary metabolite usually leads to immediate or short-term death while the absence of a secondary metabolite does not.
<em>According to the different types and diverse functions that fulfill there are an immense amount of metabolites</em>
