Are most invasive (exotic) species K-selected or r-selected species? Explain you

Question

Are most invasive (exotic) species K-selected or r-selected species? Explain your choice and why that makes sense in terms of their ecological success.

Briefly define a community and an ecosystem and describe how the two are interrelated.

Which of the following levels of organization are in order, from simplest to most complex.
a. population, organism, community, ecosystem
b. community, ecosystem, population, organism        
c. organism, community, population, ecosystem
d. population, ecosystem, organism, community
e. organism, population, community, ecosystem

Mosses growing on bare rock will eventually help to create soil. These mosses are involved in ___ succession.
a. primary
b. secondary
c. tertiary

If a farmer sprays a pesticide onto a field and kills half of the insect pests, he has caused a reduction in________.
a. field capacity
b. carrying capacity
c. population size
d. More than one of the above

What type of survivorship curve would you expect for a plant species in which only a few seeds are produced and most of these survive to produce adult plants?
a. type I
b. type II
c. type III

An ecological niche is an organism's_______ in an ecosystem.
a. location
b. habitat        
c. resources        
d.  function

No matter how rapidly populations grow, they eventually reach a limit and begin to stabilize. This is called the ______________.

Unicellular algae live in the tissues of coral animals. The algae provide food for the coral, while the coral provides a stable home for the algae. This is an example of
a. Parasitism
b. Commensalism
c. Mutualism

The vast majority of energy taken into an ecosystem is____________.
a. converted into biomass by plants.
b. utilized by secondary consumers.
c. lost as heat.
d. used by the primary consumers.
e. concentrated in the decomposers.  

A farmer is using an insecticide to treat his crops. While most insects do not survive their first exposure to the insecticide some have a gene that enables them to survive. When these survivors reproduce they will likely pass along this resistance to their offspring. This results in an increase in numbers of the insects over time. Which of the following processes applies to this survival?
a. cloning
b. mutation
c. natural selection
d. genetic engineering

What is the ecological relationship between insects and crops?
a.     mutualism
b.    competition
c.    predation

Sea anemones growing on the backs of crabs without damaging the crabs are an example of
a. Parasitism
b. Commensalism
c. Mutualism

Which of these is a population density-independent regulating factor?
a. Competition
b. Predation
c. Size of population
d. Weather
e. Resource availability

Producers are_________.
a. Autotrophs
b. Herbivores
c. Omnivores
d. Carnivores

If biological magnification occurs, the ___ will have the highest levels of toxins in their systems.
a. producers
b. herbivores
c. primary carnivores
d. top carnivores

Given the amount of sunlight that hits the plants on our planet, and the ability of plants for rapid growth and reproduction, how come we aren’t all hip deep in dead plants?

Explanation / Answer

Ans: All the species that inhabit this planet can broadly be divided into two categories k-selected species and r-selected species. Organisms which live for long, have a huge body size reach reproductive age after a considerable time, give rise few young ones and provide natal care (only animals especially mammals) are grouped under k-selected species. On the contrary, the organisms which are small sized, produce a large number of offspring or young ones, with little or no natal care are of r-selected species.

Let us observe the effect of a sudden environmental event like an earthquake on both k & r species. If the earthquake wipes out 90% of the population of a mountain gorilla (k-selected species) and pygmy marmoset (r-selected species). Mountain gorilla female gives birth to babies once in every four years when compared to pygmy marmoset which births four young ones per year.

2. Briefly, define a community and ecosystem.

Ans: Community - A group of different populations of different species interacting with each other in a region are together called community.

Ecosystem- This includes all the biotic and abiotic factors in an area. Biotics factors include plants, animals, scavengers. Abiotic factors include air, water, soil, minerals etc.,

3. Which of the following levels of organization are in order, from simplest to most complex.

Ans: e. organism, population, community, ecosystem

4. Mosses growing on the bare rock will eventually help to create soil. These mosses are involved in ___ succession

Ans: Primary

5. If a farmer sprays a pesticide onto a field and kills half of the insect pests, he has caused a reduction in________.

Ans: c. population size

6. What type of survivorship curve would you expect for a plant species in which only a few seeds are produced and most of these survive to produce adult plants?

Ans:

7.An ecological niche is an organism's_______ in an ecosystem.

Ans: d. Function

8. No matter how rapidly populations grow, they eventually reach a limit and begin to stabilize. This is called the ______________.

Ans: carrying capacity.

9. Unicellular algae live in the tissues of coral animals. The algae provide food for the coral, while the coral provides a stable home for the algae. This is an example of

Ans: c.Mutualism

10. The vast majority of energy taken into an ecosystem is____________.

Ans: lost as heat.

11. A farmer is using an insecticide to treat his crops. While most insects do not survive their first exposure to the insecticide some have a gene that enables them to survive. When these survivors reproduce they will likely pass along this resistance to their offspring. This results in an increase in numbers of the insects over time. Which of the following processes applies to this survival?

Ans: Natural selection

12. What is the ecological relationship between insects and crops?

Ans: c.predation

13. Sea anemones growing on the backs of crabs without damaging the crabs are an example of

Ans: b. commensalism

14. Which of these is a population density-independent regulating factor?

Ans: d.weather

15. Producers are_________.

Ans: a. Autotrophs

16. If biological magnification occurs, the ___ will have the highest levels of toxins in their systems.

Ans: d.top carnivores.

17. Given the amount of sunlight that hits the plants on our planet, and the ability of plants for rapid growth and reproduction, how come we aren’t all hip deep in dead plants?

Ans: Plants have a capacity to convert the light energy into starch through the process of photosynthesis. Once the plants are dead it's the work of decomposers such as fungi which feed on the dead and decaying material and return the minerals to the soil which can be again reused by the autotrophs for the production of food and the cycle continues. Hence, one can say the decomposers clean-up the environment and that's why we don't have the dead plants and animals, lying around.

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