Name __________________________________________ Date _______________

Chapter 5 Reading Questions

1. Explain the biological significance of the Dung of the Devil.

Extracts from the plant have strong antiviral properties that are very helpful for fighting disease.

2. Give 2 reasons conservation of biodiversity may be beneficial to our health.

There may be some organisms that can provide health benefits, such as the Dung of the Devil. Also, greater biodiversity allows for greater stabilization of the climate, which is necessary for our well-being.

3. Give 3 examples of how natural substances have been used to treat disease.

The rosy periwinkle is used to treat childhood leukemia and Hodgkin’s disease. The mayapple is the source of two anti-cancer drugs. Other medicines come from invertebrates such as sponges, corals, and sea squirts.

4. Which has more biodiversity a carefully tended lawn or a small plot of untended land? Explain.

A small plot of untended land has greater biodiversity, since there is a greater variety of species there than on the well-kempt and uniform lawn.

5. Define species.

A species is a group of organisms that is distinct from other groups in terms of characteristics, and that can breed with each other.

6. Approximately how many species have scientists named? How many species are estimated to live on Earth?

About 2 million have been named, and about 10 million are thought to live on Earth.

7. Compare and contrast species richness and species evenness. Use an example to explain.

Species richness – the number of species in a given area, such as a pond or a tree

Species evenness – the proportion of the number of species in an ecosystem

Two communities may have an equal species richness, but one community may be dominated by one species, while the other may have an equal number of each species.

8. How are species phylogenies determined?

They are determined by the similarity of different species (morphology and behavior)

9. List the classification system from the most broad to the most specific.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

10. Speciation is an example of microevolution or macroevolution? Explain.

Speciation is an example of macroevolution. Both result in the creation of new species. Microevolution is small-scale changes in a species that may eventually result in speciation.

11. Explain 2 ways mutations may occur. Are they good or bad? Explain.

Mutations may occur by UV radiation. It can also occur through mistakes made while DNA is copied.

12. Explain how recombination occurs.

It is the switching of one small part of a chromosome with another during meiosis.

13. Give 2 examples of how humans are purposefully or inadvertently directing evolution of organisms.

The breeding of plants and animals for human use is done purposefully. The evolution of weeds after being sprayed with herbicides is inadvertent.

14. List the 5 key ideas of Darwin’s Theory of Evolution by Natural Selection.

1. Individuals produce an excess of offspring

2. Not all offspring can survive

3. Individuals differ in their traits

4. Differences in traits can be passed on from parents to offspring

5. Differences in traits are associated with differences in the ability to survive and reproduce

15. Describe the 3 random evolutionary processes.

Genetic drift – a change in the genetic composition of a population over time as a result of random mating.

Bottleneck effect – a drastic reduction in the size of a population—known as a population bottleneck—may change its genetic composition.

Founder effect – a small portion of a population may settle in a separate location than the rest of the population. This causes a different gene pool to form.

16. Give an example of how genetic drift may have a greater effect in small populations.

There is a greater chance of genotype loss in smaller populations, since there are fewer animals for the genotype to be in.

17. What are some ways the bottleneck effect may occur and why might this lead to an extinction of a population? Give an example of the founder effect.

A disaster may occur, such as an asteroid strike or supervolcanic eruption, which could cause a bottleneck. Extinction may occur because the remaining species would not be genetically diverse enough to survive. An example of the founder effect is the Galapagos Tortoise.

18. Explain how Darwin’s finches are an example of allopatric speciation.

The finches used to have a common ancestor from the South American mainland. When those ancestors moved to the Galapagos Islands, they evolved differently, and as a result new species were formed that are different from one another.

19. Give an example of sympatric speciation.

The evolution of larger and more productive wheat because of the increase in the number of chromosome sets, from two to possibly three, four, or even six.

20. How long does evolution take?

The rate of evolution can change from hundreds to millions of years. The average rate per species is 3 million years.

21. Explain how the rate of environmental change, genetic variation, generation time and genetic engineering effect evolution.

Environmental change – the faster an environment changes, the fewer the number of species than can adapt in time

Genetic variation – the more varied a species is in genotype (and phenotype), the likelier it is that they will survive rapid environmental changes

Generation time – the less time between birth and reproduction, the better it is for evolution

Genetic engineering – desirable genes from one organism are directly placed into another organism for “instant” evolution

22. Explain the difference between fundamental niche and realized niche. Give an example.

Fundamental niche – range where a species lives optimally; for humans, it could be from 55-75 degrees Fahrenheit temperature-wise

Realized niche – range where a species actually lives in; for us, it would be from -10-95 degrees Fahrenheit

23. Would you rather be a niche generalist or niche specialist? Explain.

I would rather be a niche generalist, as they can adapt more easily to drastic changes in the environment.

24. Can we predict future species distribution? Justify your answer.

By observing past patterns in species migration, it is possible to make a rough estimate of future distributions.

25. What obstacles may prevent a species from being widely distributed?

Predators, temperature, amount of sunlight, amount of food, presence of humans and human development

26. Explain 3 reasons why species may go extinct when their habitat changes.

No place to move to, available alternatives have predators, no time to move

27. How can fossil records be useful for environmentalists?

They can be used to help determine which species used to live on Earth.

28. What is the consensus on how the dinosaurs became extinct?

When a large asteroid struck, a giant dust cloud circled the planet, blocking sunlight, stopping photosynthesis, and killing the dinosaurs.

29. What is causing the 6th mass extinction?

We are causing the 6th mass extinction through overharvesting, habitat destruction, climate change, etc.