Biosphere Contents

2. Diversity

Conclusion

It has been noted that the term biodiversity is used quite generally to encompass the overall variety of life, which is currently categorised into three domains: bacteria, archaea and eukaryota. The eukaryota are divided into four kingdoms: protozoans, plants, animals and fungi. The importance of reproduction to species survival has been noted, together with the two distinct forms of reproduction: sexual and asexual. A life cycle is the sequence of changes that occurs during the life of an individual organism.

Question and answers

1. What is a keystone species?

question 1 answers

2. What are the two branches of science that set out to provide names for living things and to arrange them within a system of classification that provides a family tree?

question 2 answers

3. What are the eight commonly used hierarchical groupings for organisms?

question 3 answers

4. Name the three domains and four Eukaryote kingdoms currently recognised.

question 4 answers

5. Why do viruses have no separate kingdom?

question 5 answers

6. What are the levels of organisation within an organism such as a human?

question 6 answers

7. What is a community?

question 7 answers

8. What are the two basic forms of reproduction?

question 8 answers

9. Why might sexual reproduction be more advantageous than asexual reproduction in the face of new disease-forming micro-organisms?

question 9 answers

Question 1 answer

A keystone species is a species that is particularly important to the functioning of an ecosystem, due to the strong relationships it has with many other species.

Question 2 answer

Taxonomy and systematics.

Question 3 answer

Each level of the hierarchy contains larger and larger groups of the previous level. In ascending order these are: Species, Genus, Family, Order, Class, Phylum, Kingdom and Domain.

Question 4 answer

Three domains:

Eukaryota
Bacteria
Archaea

Four Eukaryote Kingdoms:

Protozoans (Protists)
Fungi
Plants
Animals

Question 5 answer

Viruses have no separate kingdom because they are incapable of independent life. They may evolved on multiple separate occasions by multiple processes.

Question 6 answer

Genetic information is stored within cells, which can divide and reproduce. Similar cells come together to form tissues, which themselves are organised into organs, which carry out particular functions. Organs with similar functions form organ systems. There are various organ systems within an individual organism such as a human.

Question 7 answer

A community is a grouping of populations of different species that occur in the same environment and potentially interact.

Question 8 answer

The two basic forms of reproduction are sexual reproduction and asexual reproduction.

Question 9 answer

Asexual reproduction results in offspring genetically identical to the parent. Variations only occurs when mutations (mistakes in the copying process) take place. The advantage of sexual reproduction (whilst appearing to be less efficient) is that in each generation a new mix of genes is present in each individual. This can help sexually reproducing organisms to evolve more rapidly in response to changes in their environment.