Exam reveiw diversity of living things

Question 1

Describe the method by which organisms are named using two names. Who came up with this method and why do we use it?

Answer 1

The method by which organisms are named using two names is called binomial nomenclature. This system uses two Latin-based names: the genus name and the species name. For example, in Homo sapiens, Homo is the genus, and sapiens is the species.

Origin: Carl Linnaeus, a Swedish botanist, developed this method in the 18th century.
Purpose:
Universal Standardization: Provides a standardized naming system that can be understood internationally.
Clarity and Precision: Avoids the confusion caused by common names, which can vary across languages and regions.

Question 2

Describe the difference between a prokaryote and eukaryote.

Answer 2

Cell Structure: Lack a nucleus and membrane-bound organelles.
Genetic Material: DNA is circular and resides in the nucleoid region.
Size: Generally smaller (1-10 µm).
Examples: Bacteria and Archaea.
Eukaryotes:
Cell Structure: Have a nucleus and membrane-bound organelles.
Genetic Material: DNA is linear and enclosed within a nucleus.
Size: Generally larger (10-100 µm).
Examples: Plants, animals, fungi, and protists.

Question 3

What are the kingdoms and provide a representative organism from each.

Answer 3

Animalia: Lion (Panthera leo)
Plantae: Oak tree (Quercus robur)
Fungi: Yeast (Saccharomyces cerevisiae)
Protista: Amoeba (Amoeba proteus)
Bacteria: Escherichia coli (E. coli)
Archaea: Halobacterium species

Question 4

What are the levels of taxonomy?

Answer 4

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 5

What is the difference between a cladogram and a phylogenetic tree.

Answer 5

Cladogram:
Purpose: Shows relationships between organisms based on shared characteristics.
Structure: Branches do not represent time; focus is on the branching pattern.
Phylogenetic Tree:
Purpose: Illustrates evolutionary relationships, often incorporating time and genetic distance.
Structure: Branch lengths can represent time or genetic differences.

Question 6

what is a clade

Answer 6

A group of organisms that includes an ancestor and all its descendants, representing a single branch on a cladogram or phylogenetic tree.

Question 7

structure and function of bacteria

Answer 7

Bacteria:
Genetic Material: Circular DNA.
Metabolism: Can be autotrophic or heterotrophic.
Organelles: Lack membrane-bound organelles.
Structure: Cell wall made of peptidoglycan.

Question 8

structure and function of viruses

Answer 8

Genetic Material: DNA or RNA.
Metabolism: Lack metabolic processes; depend on host cells.
Organelles: None; not considered living cells.
Structure: Protein coat (capsid) and sometimes a lipid envelope.

Question 9

structure and function of fungi

Answer 9

Genetic Material: Linear DNA within a nucleus.
Metabolism: Heterotrophic, often decomposers.
Organelles: Membrane-bound organelles including a nucleus and mitochondria.
Structure: Cell wall made of chitin.

Question 10

structure and function of protists

Answer 10

Genetic Material: Linear DNA within a nucleus.
Metabolism: Can be autotrophic, heterotrophic, or mixotrophic.
Organelles: Membrane-bound organelles including a nucleus, mitochondria, and sometimes chloroplasts.
Structure: Diverse; some have cell walls, others do not.

Question 11

Explain what biodiversity is and why it is important to maintaining viable ecosystems.

Answer 11

Biodiversity: The variety of life in a particular habitat or ecosystem.
Importance:
Ecosystem Services: Pollination, nutrient cycling, water purification.
Resilience: More diverse ecosystems can better withstand environmental changes and disturbances.
Human Benefits: Provides resources such as food, medicine, and materials.

Question 12

How are fungi different from plants?

Answer 12

Fungi:
Cell Wall Composition: Made of chitin.
Nutrition: Heterotrophic, absorb nutrients from their environment.
Reproduction: Primarily through spores; both sexual and asexual reproduction.
Mobility: Non-motile.

Plants:
Cell Wall Composition: Made of cellulose.
Nutrition: Autotrophic, perform photosynthesis.
Reproduction: Involves seeds, spores, or vegetative reproduction.
Mobility: Non-motile.

Question 13

What are the three types of symmetry that exist in animals?

Answer 13

Asymmetry: No symmetry (e.g., sponges).
Radial Symmetry: Symmetry around a central axis (e.g., jellyfish).
Bilateral Symmetry: Divisible into symmetrical halves on either side of a unique plane (e.g., humans, insects).