Biology and the Tree of Life

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Questions and Answers

Which of the following is NOT a characteristic of life?

Is unable to replicate (correct)

Requires energy

Contains genetic information

Basic unit is a cell

What is the basic unit of life?

Genetic information

Adaptation

Energy

Cell (correct)

What is a hypothesis?

A proposed explanation for a set of observations

A proposed explanation for a broad class of phenomena or observations

A specific, testable, speculative guess that has yet to be tested (correct)

A general explanation that has already been extensively tested and is generally accepted

What is a theory?

A general explanation that has already been extensively tested and is generally accepted Signup and view all the answers

What did Louis Pasteur's experiment aim to investigate?

The origin of cells Signup and view all the answers

Why do DNA and other complex structures and processes in different organisms suggest a common ancestor?

Because they have similar functions Signup and view all the answers

What does the term 'homologies' refer to?

Similarities that arise from sharing a common ancestor Signup and view all the answers

Which of the following is NOT a requirement for something to be considered alive?

Is capable of adaptation Signup and view all the answers

What is the main difference between a hypothesis and a theory?

A hypothesis is specific and testable, while a theory is general and accepted Signup and view all the answers

What does evolution modify instead of forming each new species from scratch?

Basic design Signup and view all the answers

Which of the following is true about the forelimbs of various mammals?

They have slightly modified bones for different purposes. Signup and view all the answers

What is the hereditary material in all life forms?

DNA Signup and view all the answers

What is the basic structure of the cell membrane?

A bilayer of lipids Signup and view all the answers

How do cells use and release energy?

Through the ATP-ADP cycle Signup and view all the answers

What is the main molecule used for energy currency in all organisms?

ATP Signup and view all the answers

What is the main difference between eukaryotic and prokaryotic cells?

Eukaryotic cells have a nucleus, while prokaryotic cells do not. Signup and view all the answers

What is speciation?

The evolution of two distinct species from a common ancestral species. Signup and view all the answers

Which domain is more closely related to eukaryotes than to other prokaryotes?

Archaea Signup and view all the answers

Is evolution purposeful?

No, it is a random process. Signup and view all the answers

What is natural selection?

Changes in a population resulting from the environment selecting for different traits. Signup and view all the answers

Study Notes

Characteristics of Life

Not all characteristics apply universally; for instance, viruses do not meet all criteria of life.
A living organism must exhibit characteristics such as growth, reproduction, response to stimuli, and metabolism.

Basic Unit of Life

The cell is the fundamental building block of life, serving as the smallest unit capable of performing all life processes.

Hypothesis vs. Theory

A hypothesis is a testable prediction or explanation for an observable phenomenon.
A theory is a well-substantiated explanation derived from a body of evidence, commonly accepted in the scientific community.

Louis Pasteur's Experiment

Aimed to investigate the origin of microbial life and the process of spontaneous generation, ultimately demonstrating that microorganisms come from other microorganisms.

Common Ancestors and DNA

Similarities in DNA and complex structures across species suggest a shared ancestry, indicating that diverse organisms evolved from a common ancestor over time.

Homologies

The term 'homologies' refers to similarities in structure or genes between different species, indicating common ancestry, despite possible functional differences.

Requirements for Life

Certain requirements such as growth, reproduction, and response to environment are necessary for classification as a living entity.

Evolution and Speciation

Evolution modifies existing species through adaptation over time, rather than creating them independently from scratch.
Speciation is the process whereby new distinct species arise, often as a result of evolutionary changes.

Forelimbs of Mammals

The forelimbs of various mammals share underlying structural similarities (homologous structures), indicating a common evolutionary origin despite differing functions.

Hereditary Material

DNA serves as the hereditary material in all life forms, coding for genes and facilitating the inheritance of traits.

Cell Membrane Structure

The basic structure consists of a phospholipid bilayer with embedded proteins, creating a semi-permeable barrier that regulates material entry and exit.

Energy Use in Cells

Cells use and release energy through metabolic processes, primarily involving the breakdown of nutrients to generate ATP (adenosine triphosphate).

Energy Currency

ATP is the main molecule used for energy currency, functioning as a primary energy source for cellular processes.

Eukaryotic vs. Prokaryotic Cells

Eukaryotic cells have a defined nucleus and organelles, while prokaryotic cells lack a nucleus and are generally simpler in structure.

Archaea is more closely related to eukaryotes than to other prokaryotes, based on genetic and biochemical evidence.

Purposefulness of Evolution

Evolution is not purposeful; it occurs through natural selection and random mutations rather than a directed process.

Natural Selection

Natural selection is the process by which individuals better adapted to their environment tend to survive and reproduce, leading to gradual evolutionary change.

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Description

Test your knowledge of biology and the tree of life with this quiz. Learn about biology vocabulary, the process of biological experimentation, and the principles of natural selection and evolution. Explore the characteristics of life, including energy requirements, cells, genetic information, replication, adaptation, and evolution. Find out if viruses are considered alive and discover more about proposed explanations in biology.