Life: The Science of Biology - Lecture Notes (11e)

Question-and-Answer flashcards covering key concepts from the lecture notes.

When and where are the course lectures and recitations held (as listed in the notes)?

Lectures: MWF 10:00–10:50 am in 121 Lawrence Hall. Recitations: Thursdays at 9:00 am (Thaw Hall), 10:00 am (Thaw Hall), 1:00 pm (1501 Posvar Hall), and 2:00 pm (1501 Posvar Hall).

What are the two main formats of class meetings described?

Lectures and Recitations.

What does abiogenesis mean?

The origin of life from non-living chemical processes.

Name a major theme in Lecture 1 related to the origin and evolution of life on Earth.

The evolution of life, including the origin of cells, photosynthesis, the origin of a eukaryotic cell, multicellularity, and key evolutionary events like the Cambrian explosion.

What explains the origin of a eukaryotic cell according to the notes?

Endosymbiosis theory; mitochondria and chloroplasts originated from engulfed bacteria.

Why is photosynthesis significant in the history of life?

It released oxygen into the atmosphere, enabling aerobic (oxygen-using) metabolism and more efficient energy production.

What event is associated with a rapid diversification of animal life around 540 million years ago?

The Cambrian explosion (adaptive radiation) driven by higher oxygen, new ecological niches, predation, and genetic changes (e.g., Hox genes).

What evidence supports a common origin of life?

Shared characteristics such as cells, metabolism, genetic information, and a universal genetic code.

What evidence supports a common genetic background across life?

The universality of the genetic code and other core molecular features across diverse organisms.

What is meant by the 'origin of biological diversity'?

Evolutionary processes (such as natural selection, mutation, genetic drift, gene flow) that generate diversity among living things.

What do all organisms have in common?

Made up of cells; composed of a common set of molecules; metabolism; contain genetic information; use a universal molecular code; regulate internal environments; exist in populations that evolve; reproduction.

Which of the following are considered living outside a host: influenza virus, fungi spores, moss spores, bacteriophage?

Fungi spores and moss spores are living; influenza virus and bacteriophage are not living outside a host.

Which of the following represent living forms: influenza virus, fungi spores, moss spores, bacteriophage?

Fungi spores and moss spores are living; influenza virus and bacteriophage are not living outside hosts.

What is the Miller–Urey experiment designed to simulate?

Early Earth chemical conditions to test whether simple molecules could form more complex organic compounds (chemical evolution).

What gases were used in the Miller–Urey atmospheric chamber (as listed in the notes)?

NH3 (ammonia), CH4 (methane), H2 (hydrogen), CO2 (carbon dioxide).

What compounds were produced in the Miller–Urey oceanic chamber?

Amino acids, sugars, nitrogenous bases, formaldehyde, acetaldehyde, and other organic molecules.

What is the proposed sequence for the evolution of cellular complexity?

Liposomes → Prokaryotic cells → Eukaryotic cells.

Which organelles are central to the endosymbiosis theory for the origin of eukaryotic cells?

Mitochondria and chloroplasts.

What key metabolic shift followed the advent of photosynthesis?

Evolution of aerobic metabolism using oxygen as the final electron acceptor, yielding more ATP.

How do prokaryotic and eukaryotic metabolism differ in ATP yield in general terms?

Anaerobic metabolism yields less ATP than aerobic metabolism, which uses O2 and yields higher ATP.

Which organisms contributed to the oxygenation of Earth's atmosphere?

Cyanobacteria.

What is the basic photosynthesis equation provided in the notes?

6 CO2 + 12 H2O → C6H12O6 + 6 O2 + 6 H2O.

Give examples of endosymbiotic relationships cited as recent evidence for endosymbiosis.

Algae living in coral cells; Blochmania bacteria inside specialized cells of an ant.

How is multicellularity described to have evolved in the notes?

Through cellular specialization within a cell colony, with some cells becoming somatic and others reproductive.

Name the volvocine algae mentioned that show increasing cellular differentiation.

Gonium pectorale; Eudorina elegans; Pleodorina californica; Volvox carteri; Volvox aureus.

What underlies multicellular life in terms of gene expression?

Differential gene expression leading to different cell shapes and functions.

What percent of Earth's history occurred in the Precambrian era?

About 88%.

Which major eras are listed in the notes, from oldest to most recent?

Precambrian, Paleozoic, Mesozoic, Cenozoic.

What factors drove the Cambrian explosion according to the notes?

Higher oxygen levels, ecological diversification, predation, and the evolution of more complex body plans via gene changes (Hox genes).

What is the role of Hox genes in evolution?

Gene duplications and diversification of Hox genes led to more complex body plans and regional differentiation.

What are the core criteria for a common origin of life as listed in the tree of life concept?

Made of cells; metabolism; genetic information; genetic code; reproduction; populations that evolve; regulate environments.

What does the universal genetic code determine?

The order of amino acids in a protein based on the information encoded in DNA.

How similar are human, cow, and pig insulin sequences according to the notes?

Very similar; human vs. cow differ by three amino acids; human vs. pig differ by one.

What evidence does insulin provide about genetics across species?

Demonstrates conservation of the genetic code and similar protein sequences across diverse species.

What are the main mechanisms of evolution listed?

Natural selection; sexual selection; genetic drift; gene flow; mutation.

What levels of biological organization does BIOSC 0150 cover according to the notes?

Basic principles from multiple levels of organization (cells, tissues, organs, organ systems, etc.).