Principles of Biology Lab II Midterm

All living organisms share several key characteristics:

All living organisms share several key characteristics:

1. Order

2. Sensitivity or response to the environment

3. REPRODUCTION

4. Growth and development

5. Regulation

6. Homeostasis

   1. Energy processing

Living organisms are part of a highly __________ ____________.

structured; hierarchy

Organization of Life:

1. Organelle- nucleus

2. Cells- human blood cells

3. Tissues- human skin tissue

4. Organs- stomach

5. Organ systems- digestive system

6. Organisms- pine tree

7. Populations- a group of pine trees

8. Communities- pine trees and animal species together

9. Ecosystem- coastal ecosystem including living organisms and the environment

10. Biosphere- ALL ecosystems on the Earth.

Features of ALL cells:

the plasma membrane, cytoplasm, DNA, ribosomes

Characteristics of prokaryotic cells

nucleoid, no membrane-bound organelles, cell wall, and some have flagella or pili

Characteristics of eukaryotic cells

larger, more membrane-bound organelles, true nucleus (DNA surrounded by a membrane), and organized

Function of a phylogenetic tree

they show the relationship of the three domains of life

What are the three domains of life?

Bacteria, Archaea, Eukarya

Define Taxonomy

the science of classifying organisms

What is the scientific name for the common dog in binomial nomenclature?

Cannus lupus familiaris

Forming a Hypothesis

Hypotheses must be testable and falsifiable.

Experimental Design

Consider sample size, selection, and how to avoid bias.

Experimental Variables

Determine the independent and dependent variables and what variables to control in the experiment.

Interpreting Results

Gather data by measuring the dependent variable then assess whether the results are statistically significant

Darwin's 3 principles of natural selection

1. Most characteristics of organisms are inherited or passed from parent to offspring.

2. More offspring are produced than are able to survive, so resources for survival and reproduction are LIMITED. Thus, there is COMPETITION for those resources in each generation.

3. Offspring VARY among each other in regard to their characteristics and those variations are inherited.

Natural Selection

a process that leads to greater adaptation of the population to its environment.

Finches from the Galapagos Islands

the beaks of the finches were different based on their distinct food sources.

Explain evolution

1. Natural selection drives evolution, but first we need VARIATION

2. Variation arises from genetic mutations

3. Diversity is encouraged by SEXUAL reproduction

4. Environments change, and selective pressures shift forces adaptations

T/F Evolution is a scientific theory.

True

T/F Individuals evolve.

False, populations evolve

T/F Theory of Evolution addresses how species change over time.

True

Define species

group of organisms that can interbreed and produce fertile offspring

Define gene pool

The collection of all the genes in a population

rooted phylogenetic tree

Phylogenetic trees that originate back to one common ancestor

Characteristics of a Virus

acellular and parasitic entities that are NOT CLASSIFIED within any kingdom.

Progressive hypothesis of viruses

viruses arose from genetic elements that gained the ability to move between cells

Regressive hypothesis of viruses

viruses are remnants of cellular organisms

Virus-first hypothesis of viruses

viruses predate or coevolved within their current cellular hosts

complex virus shape

T4 bacteriophage

enveloped virus shape

Helical nucleocapsid: influenza virus \n Icosahedral nucleocapsid: HIV

nonenveloped virus shape

Helical: tobacco mosaic virus \n Icosahedral: poliovirus

Steps of viral infection

1. Attachment- phage attaches to the surface of the host cell

2. Entry- viral DNA enters the host cell

3. Replication- viral DNA replicates and its proteins assemble

4. Assembly- new viral particles are assembled

5. Release- the cell lyses, releasing newly made virions

T/F Some hosts are used more than once to make new viruses

True

Acute infection

symptoms get INCREASINGLY worse for a SHORT period followed by the elimination of the virus from the body by the immune system and recovery

Long-term chronic infections

the continued presence of infectious virus following the primary infection and may include chronic or recurrent disease.

Asymptomatic infections

viruses force cells to produce virions without causing any symptoms in the host.

Examples of human viruses

Poliovirus, HIV, and Influenza virus (A/B)

Live attenuated vaccine

weakened live virus inserted in PARTS

Inactivated vaccines

dead organisms injected into patient to build immunity

Toxoid vaccines

chemically or thermally modified toxins used to stimulate active immunity

subunit vaccines

use antigenic fragments to stimulate an immune response

Why is the COVID-19 vaccine different?

The RNA code is directly injected into you.

anti-viral drugs

drugs that inhibit the virus by BLOCKING the actions of one or more of its proteins. Therefore, symptoms are MINIMIZED.

Define ecology

the study of the interactions of living organisms with one another and with their environment

Levels of Ecological research

-Organismal Ecology \n -Population Ecology \n -Community Ecology \n -Ecosystem Ecology \n -Biosphere Ecology

Define biomes

large ecosystems that cover huge geographic areas distinguished by characteristic temperature and precipitation

How to characterize a population

1. Population size (N)

2. Total number of individuals

3. Population density

4. The number of individuals within a specific area

T/F populations with fewer individuals are more stable compared to larger ones.

False, more individuals are stable based on their genetic variability.

uniform distribution

Distribution where species are spaced evenly

random distribution

species arranged in no particular pattern

clumped distribution

species located in the same area

How have humans overcome the caring capacity of the earth?

Multi-story house buildings

The human population is growing exponentially, what potential problems could this cause?

Famine, disease, and large scale death.

Define innate behavior

Genetically programmed behavior pattern of an animal.

Define learned behavior

a relatively permanent change in behavior, or the potential for behavior, that results from experience

examples of innate behavior

suckling of newborn mammals, birds building nests, spiders weaving webs

example of learned behavior

habituation: an animal stops responding to a stimulus after a period of repeated exposure

________ of the three domains are _____________.

two; prokaryotic

Who were the first inhabitants of Earth?

prokaryotes

Describe the earth's early atmosphere.

the atmosphere was anoxic, so only anaerobic organisms could survive, and autotrophic organisms converted solar into chemical energy.

Describe cyanobacteria

blue-green algae evolved from simple phototrophs and began oxygenating the earth.

Define extremophiles

organisms that live in extreme environments: \n Extreme heat, pressure, and cold

Acidophiles

grow in pH 3 or below (acidic)

Alkaliphiles

\n grow in pH 9 or above (basic)

Thermophiles

grow in temperatures of 60-80 degrees Celsius (hot)

Hyperthermophiles

grow in temperatures of 80-122 degrees Celsius (extreme hot)

Psychrophiles

grow in temperature of -15-10 degrees Celsius (cold)

Halophiles

grow in salt concentrations of at least 0.2 M (salty)

Different prokaryotic shapes:

1. Cocci (spherical)

2. Bacilli (rod)

3. Spirilli (spiral)

Bacteria vs. Archaea

Bacterial cells walls contain peptidoglycan \n Archaeal cells walls do not

gram positive vs gram negative bacteria

Gram-positive: have simple cell walls with a thick layer of peptidoglycan. \n \n Gram-negative: more complex cell walls, less peptidoglycan, which is located between 2 membranes. More resistant to antibiotics.

Structural differences and similarities between Bacteria and Archaea

Cell type: both Prokaryotic \n Cell morphology: both variable \n Cell wall: bacteria- contains peptidoglycan vs archaea- doesn't \n Cell membrane type: bacteria- BILAYER vs archaea- bi/mono \n P.M. lipids: bacteria- fatty acids vs archaea- phytanyl groups

Prokaryote Reproduction

asexual binary fission

steps of binary fission in prokaryotes

Parent cell, DNA duplicates, cytoplasm divides, and two daughter cells.

Define epidemic

a disease that occurs in an unusually high number of individuals in a population at the same time.

Define pandemic

a widespread, usually WORLDWIDE, epidemic

Define endemic

a disease that is constantly present, usually at a low incidence, in a population.

Define zoonoses and give an example

a disease that can be transmitted to humans from animals. \n example: SARS, Ebola

How does antibiotic resistance occur?

1. high number of bacteria and a few of them are resistant to antibiotics

2. antibiotics kill bacteria causing the illness, as well as good bacteria protecting the body from infection

3. the resistant bacteria now have preferred conditions to grow and take over

4. bacteria can even transfer their drug resistance to other bacteria causing more problems

Examples of good bacteria

probiotics (yogurt) \n \n natural gut bacteria \n \n microbiome of body \n \n started cultures (cheeses, beer, wine)

Describe the gut microbiome

help us digest our food, produces crucial nutrients for us, and help train our immune systems to function correctly

Viruses vs. Bacteria

1. Size- virus = small and bacteria = bigger

2. Reproduction- bacteria = reproduces and virus = need a host in order to multiply

3. Illness/Treatment- virus = shorter period of illness treated by rest/anti-virals and bacteria = longer period of illness treated by antibiotics

Four sub classes of Eukaryotes

animal cells, plant cells, protists, and fungi

Animal vs. Plant Cells

Plant cells have cell walls, vacuoles, and chloroplasts while animal cells do not

T/F yeast is NOT a fungus

False, yeast is a fungus

Define protists

eukaryotes that are not part of the plant, animal, or fungi kingdoms

protist cell structure

Unicellular, colonial and multicellular, Nucleus and organelles

How do protists protect themselves?

membrane, cell wall, silica-based shell, and pellicles of interlocking protein strips.

How do protist move?

1. Pseudopodia

2. Cilia

3. Flagellum

Protist metabolism

they exhibit many forms of nutrition and may be aerobic or anaerobic.

Protist reproduction

Asexual: identical copy of parent; fission. \n Sexual: two parents, often involves conjugation (two join together and exchange genetic material using a second nucleus, then divide to produce four protists)

Where do most protist live?

water (aquatic): freshwater, marine, damp soil, and snow environments \n a few protists live on DEAD organisms or their wastes \n (contributing to decay)

Describe bioluminescence

protists that let off the light.

Describe paramecium

1. primitive mouth = oral groove (eat)

2. anal pore (excrete waste)

3. Contractile vacuoles = excrete excess water

4. Cilia = enable movement

protists as primary producers

1. some protists (including plankton) feed most of the world's aquatic species directly or indirectly.

2. approximately one-quarter of the world's photosynthesis is conducted by protists such as dinoflagellates, diatoms, and multicellular algae.

Protists as decomposers

1. Protist saprobes are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes.

2. Saprobic protists have the essential function of returning inorganic nutrients to the soil and water. This process allows for new plant growth.`

Pathogenic Protists

malaria and African sleeping sickness

Plant parasites

P. viticola- destroys food crops causing downy mildew (yellow)

Traits of Land Plants

1. the alternation of generations

2. a sporangium in which the spores are formed

3. a gametangium that produces haploid cells

4. apical meristem tissue in roots and shoots

Explain alternation of generations

*The gametophyte is haploid and produces haploid gametes by mitosis \n *Fusion of gametes gives rise to diploid sporophytes, which produce haploid spores by meiosis