Biology: Classifying Living Things

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Questions and Answers

What does the term 'virus' etymologically derive from?

Contagion

Poison (correct)

Life

Disease

Which component of a virus is responsible for entering a host cell?

Capsid (correct)

DNA or RNA

Base plate

Tail fibers

Which of the following statements about viruses is accurate?

They can survive indefinitely outside a living organism.

They can replicate outside a host cell.

They have cellular structures.

They require a host to reproduce. (correct)

What maintains the infectivity of a virus when it is stored outside a living cell?

Its DNA or RNA Signup and view all the answers

What is true about the specificity of viruses?

Plant viruses can only infect plant cells. Signup and view all the answers

Which part of the virus is made entirely of proteins?

Capsid Signup and view all the answers

What characteristic is common to all viruses?

They are non-cellular. Signup and view all the answers

Which of the following is NOT a structural component of a virus?

Mitochondria Signup and view all the answers

What is the main principle behind Darwin's Theory of Evolution?

Natural selection leads to survival of the fittest. Signup and view all the answers

What is taxonomy primarily concerned with?

The classification and naming of organisms. Signup and view all the answers

Which of the following best describes binomial nomenclature?

A method of naming organisms with two descriptive parts. Signup and view all the answers

Why were early classification systems problematic according to the content?

They confused organisms with common names. Signup and view all the answers

What happened to the concept of classification as new organisms were discovered?

Existing classifications faced challenges and needed revisions. Signup and view all the answers

Which statement about natural selection is true?

It results in the survival of organisms best adapted to their environment. Signup and view all the answers

What method did Aristotle use to classify animals?

Dividing them into categories of land, water, and air. Signup and view all the answers

What was one of the key achievements of Carlos Linnaeus in classification?

He introduced a structured system for classifying organisms. Signup and view all the answers

What term is used to group reptiles, birds, and mammals based on their shared embryological structure?

Amniotes Signup and view all the answers

What can be inferred from comparing the proteins of two organisms?

Proteins can show how long ago two species diverged. Signup and view all the answers

Why are similarities in genetic sequences important?

They reveal how recently two species shared a common ancestor. Signup and view all the answers

Which of the following is an example of biochemical similarity?

The comparison of amino acid sequences. Signup and view all the answers

What does phylogeny represent in the study of evolutionary relationships?

Lines of evolutionary descent. Signup and view all the answers

How can cellular organization provide evidence of relatedness among organisms?

By examining the existence of cellular structures like cell walls. Signup and view all the answers

What does the presence of the same gene for myosin in both humans and yeasts suggest?

They share a distant common ancestor. Signup and view all the answers

What is primarily observed to determine genetic similarities between organisms?

The number and type of chromosomes. Signup and view all the answers

What characteristic distinguishes bacteriophages from other viruses?

They specifically target certain types of bacteria. Signup and view all the answers

Which statement best describes the living status of viruses?

Viruses are non-living as they cannot function without a host. Signup and view all the answers

During which phase of the lytic cycle does a virus enter a host cell?

Attachment Signup and view all the answers

What happens to a host cell during a lytic infection?

The host cell bursts after the virus makes copies of itself. Signup and view all the answers

Which statement accurately describes the lysogenic cycle?

The viral genetic material is incorporated into the host's DNA. Signup and view all the answers

Which statement about viruses is NOT true?

Viruses require antibiotics to be killed. Signup and view all the answers

Which of the following is a function of the viral genome?

It directs the synthesis of viral proteins in the host cell. Signup and view all the answers

What signifies that a virus has become 'active'?

It enters a host cell for reproduction. Signup and view all the answers

What is the main function of photoautotrophs?

To convert carbon dioxide and water into glucose using light energy Signup and view all the answers

Which of the following limits the reproduction of prokaryotic cells?

Depletion of food supply and metabolic waste accumulation Signup and view all the answers

What is binary fission?

A method of asexual reproduction resulting in two identical daughter cells Signup and view all the answers

What happens during conjugation in bacteria?

Bacteria exchange genetic information through a bridge Signup and view all the answers

Why are bacteria considered vital to maintaining the living world?

They recycle essential elements by decomposing dead organisms Signup and view all the answers

What is a potential consequence if bacterial reproduction is unchecked?

Formation of a massive living colony from one cell Signup and view all the answers

What energy source do chemoautotrophs primarily use?

Energy from inorganic reactions Signup and view all the answers

How does conjugation increase genetic diversity in bacterial populations?

By allowing the exchange of genes between cells Signup and view all the answers

Study Notes

Classifying Living Things

Scientists use a system to arrange living things by grouping and classifying them, constantly improving with technological advancements.
Darwin's theory of evolution explains that more offspring are produced than can survive, leading to competition for resources.
Natural selection states that individuals best adapted to their environment are more likely to survive, reproduce, and pass on their traits.
Current species evolved from ancestors, undergoing modifications over time.

Taxonomy

The branch of biology that classifies organisms and assigns universal scientific names.
Early attempts at classification, like Aristotle's system, grouped organisms by their common traits, often leading to incorrect pairings.
The use of common names for different species caused confusion.
Carl Linnaeus created a system based on structural similarities, assigning scientific names using binomial nomenclature.
He divided organisms into two kingdoms: Plants and Animals, further subdividing them into seven levels of classification.
Observing developmental stages, like embryonic development, helps classify organisms based on shared structures.

Evidence for Evolutionary Relationships

Cellular Organization: Shared features like cell walls in plants suggest evolutionary ties.
Biochemical Similarities: Comparing chemical compounds within cells provides evidence for relationships between organisms.
Molecular Clock: Differences in amino acid sequences of proteins between organisms indicate how long ago they diverged from a shared ancestor.
Evolutionary Relationships: Categorizing organisms based on their evolutionary ancestry.
Genetic Similarities: Comparing chromosome numbers and types reveals relationships between organisms.
DNA Sequences: The more similar the DNA sequences of two species, the more recently they shared a common ancestor, indicating close relatedness.

Viruses

Definition: Non-cellular entities that require a living host to replicate.
Structure: Consists of DNA or RNA enclosed in a protein coat called a capsid.
Function: Enters a host cell and utilizes its machinery to produce more viruses.
Specificity: Viruses are highly specific to the cells they infect, targeting certain tissues or organisms.
Replication: Viruses reproduce through two methods: the lytic cycle and the lysogenic cycle.
Lytic Cycle: The virus replicates rapidly, destroying the host cell.
Lysogenic Cycle: The virus incorporates its DNA into the host's DNA, replicating with the host cell without immediate harm.

Bacteria

Reproduction: Bacteria generally reproduce asexually through binary fission, creating two identical daughter cells.
Conjugation: A process where bacteria exchange genetic material through a hollow bridge, increasing genetic diversity.
Importance: Bacteria are vital for maintaining life on Earth.
Decomposers: They recycle essential elements like carbon and nitrogen from dead organisms.

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Description

Explore the fascinating world of taxonomy and the classification of living organisms. Learn about Darwin's theory of evolution and how natural selection shapes species over time. This quiz will challenge your understanding of biological classification and the historical figures who contributed to it.