Bio102, Chapter 1 - The Science of Biology

Chapter 1 bio lecture

The ability to respond to a stimulus is an example of __________.

Sensitivity

Which of the following domains or groups is non-living?

Viruses

A group of similar individuals that can interbreed would be considered a(n) __________.

species

The ultimate source of energy for life on earth is ___________.

The sun

In science, a hypothesis can be proven true.

False

Populations and resources grow at the same rate.

False

All the populations of different species living in one area would be categorized as ___________

a community

Who wrote On the Origin of Species by Means of Natural Selection?

Charles Darwin

All the organisms and the physical environments on earth constitute the __________

biosphere

DNA

guides and developes how you will grow overtime, passes off to offspring

Virus are not considered living things because _____

they cannot reproduce without a host cell

Gregor Mendel carried out breeding experiments with garden peas in his monastery.  Based on his experimental results he was able to explain how traits are inherited.  This would be an example of deductive reasoning.

False

Birds, bees, and bats have all evolved wings but have different evolutionary histories.  The wings of these animals are examples of __________

analogous structures

In a population of snails the individuals with the thickest shells survive and reproduce more than those with thinner shells.  Assuming shell thickness is a heritable trait, what should happen to the mean shell thickness in a population of snails over time??

increase

Form follows function

The shape of something can predict what it does.

Enzymes

Proteins that are gonna break molecules apart for you. They need to be exactly the right shape to do their job.

biological catalysts—mostly proteins or catalytic RNA molecules—that speed up chemical reactions in living cells without being consumed in the process.

A bird on a cold night shivers to maintain its body temperature.  What property of life does this example represent?

homeostasis

A researcher predicts that chemical X will make plants grow taller, and designs an experiment to test the prediction.  This prediction can be classified as a(n) ___________

Hypothesis

The hypothesis in a seed germination experiment is as follows:  Light is necessary for lettuce seed germination.  Groups of lettuce seeds are placed in light with warm temperatures and adequate moisture.  Another set of identical seeds is placed in the dark under the same conditions.  What is the dependent variable?

germentation rate

Biosphere:

All regions of earth that hold life

Hierarchy of organization

Cellular level

Organismal level

Populational level

Ecosystem level

Energy

the capacity to do work, energy flows in one direction through the biosphere

Domain

dividing organisms based on their cell type, whether they're prokaryotic or eukaryotic.

Prokaryotic domains Bacteria and Archaea

Of the 3 domains, Archaia, Domain Archaia, and Domain Bacteria are prokaryotic cells, no nucleus.

• No Nucleus: Prokaryotic cells lack a membrane-bound nucleus and keep their genetic material in a region of the cytoplasm called the nucleoid.

• No Membrane-Bound Organelles: They do not have complex internal compartments like mitochondria, the endoplasmic reticulum, or Golgi apparatus.

• Simple Structure: Most are single-celled and smaller than eukaryotic cells, featuring ribosomes to make proteins and a protective cell wall.

Single-celled organisms in which DNA is not

contained in a nucleus

Bacteria Archaea

Most numerous organisms on More closely related to eukaryotes

earth than to bacteria

eukaryotic domain is Eukarya (or Eukaryota),

Everything that has cells with a nucleus

• True Nucleus: Cells feature a distinct nucleus enclosed by a double membrane holding genetic material (DNA).

• Membrane-Bound Organelles: Functions are compartmentalized into structures like mitochondria, the endoplasmic reticulum, and (in plants) chloroplasts.

• Cytoskeleton: A well-developed internal protein network provides structural support and helps the cell move.

• Cell Size: Eukaryotic cells are generally larger and more structurally complex than prokaryotic cells.

• Reproduction: Involves mitosis and meiosis, supporting both asexual and sexual reproduction

Organisms whose DNA is contained in nucleus

– Protists

• Simplest eukaryotes with great diversity

– Fungi

• Eukaryotic consumer, breakdown food

externally

– Plant

• Usually multi-celled, photosynthetic producer

– Animal

• Multi-celled consumer that ingest food or juices

of other organisms

species

It's a group of organisms that can interbreed and produce viable offspring. Viable just means they're not sterile

Carl Linnaeus,

Carl Linnaeus, took all of those species and organized them in his book. using things that have similar characteristics to put them together, and the genus name is the next category. So species are organized into genera when they share a bunch of unique traits

Genus name

genetic group

Species

Taxonomy: practice of naming and classifying

species; developed by Linnaeus

– Species: organisms which share the same

characteristics and are capable of

exchanging genes/producing offspring

– Genus: a group of species that share a set

of unique traits

• Every species is given a unique two-part

scientific name consisting of its genus and

species. ( Humans: Homo sapiens.)

Taxon: a group of organisms that share a

unique set of traits

– Each taxon consists of next lower taxon

• Domain, kingdom, phylum, class,

order, family, genus, species

Taxonomic Classification

1. Domain: The highest and broadest rank, split into Archaea, Bacteria, and Eukarya. 

   
   

2. Kingdom: Major groups like Animalia, Plantae, Fungi, and Protista. 

   
   

3. Phylum (or Division for plants): Groups organisms based on major body plans or structural designs

1. Class: Subdivisions of a phylum (e.g., Mammalia for milk-producing animals with hair). 

   
   

2. Order: A cluster of related families (e.g., Carnivora). 

   
   

3. Family: A collection of related genera (e.g., Felidae for cats). 

   
   

4. Genus: A group of very close species; forms the first part of a scientific name. 

   
   

5. Species: The most specific rank representing a distinct, individual type of organism

Ernst Mayr

defined a species as one or more

groups of individuals that potentially can

interbreed, produce fertile offspring, and do not

interbreed with other groups.

Hypothesis

a proposed, tentative explanation for a phenomenon, observation, or scientific problem that can be tested through investigation or experiment

Control group

the standard used for comparison that does not receive the test treatment or intervention

Experimental group

the group in a scientific experiment that receives the specific treatment, intervention, or change being tested

The Scientific Method—The Experiment

Variable

– Characteristic that differs among individuals or

over time

• Experimental group

– Group of individuals who have a certain characteristic or receive a certain treatment

• Control group

– Group not exposed to the independent variable

being tested

• Data

– Test results from experiment/research

Deductive reasoning

Uses general principles to make specific

predictions

Inductive reasoning

Uses specific observations to develop

general conclusions

• Primary way of reasoning in hypothesis-

driven science

Emergent property

A characteristic that a complex system has, but the individual parts of that system do not have on their own. These properties appear only when the parts interact with one another within a larger whole. [1, 2]

Cell Theory

all organisms are made up of cells, some things are single cells, some things are multiple cells, but the cell is the basic unit of living things, and cells always come from pre-existing cells.

Evolution

explains the unity and the diversity that we see in living things. By unity, I mean, all the stuff that they have in common. So the fact that all living things use DNA, that's the unity

Unifying themes

Relationship between structure and function

– Function is dependent upon structure

– When we know function of a particular structure,

we can infer function of similar structures found in

different contexts

– Biologists study both aspects

• Study structure to learn function

• Know function, so look for that structure in

other organisms

Molecular basis of inheritance

– Explains continuity of life

– DNA, composed of nucleotides (4 types)

– Specific sequence of nucleotides make up a gene, a

discrete unit of information

– Entire set of DNA instructions is genome

Fitness

survival and reproduction relative to everybody else in the population

Artificial Selection

the human-directed process of choosing specific plants or animals to reproduce based on desirable traits

Homology

a similarity between structures, genes, or topological spaces that comes from a shared origin or common ancestry