SBI3U Final Exam Review : Unit 1 - Diversity of Living Things

Symbiosis

A close, prolonged association between two or more different biological species

Mutualism

A symbiotic relationship where both parties benefit from the interaction

Example of mutualism

Mycorrhizae is a fungi that lives on the roots of plants. The fungi increases the surface area that the plant can absorb nutrients, and the plant gives the fungi sugars as food.

Commensalism

A symbiotic relationship between two species where one benefits from the other without causing harm

Example of commensalism

Cattle egrets perch on cattle that stir up insects in the grass for the birds to eat

Parasitism

A symbiotic relationship between two species where one benefits at the harm or expense of the other

Example of parasitism

Cordyceps is a parasitic fungi that invades the body of an insect and manipulates it to act in a way beneficial to the fungi, which eventually kills the host insect.

Dichotomous Key

An identification tool consisting of a series of two-part choices that lead the user to a correct identification

How to use a dichotomous key

It starts with two identifiable features, and the confirmation of either feature will indicate a species name or lead to another pair of identifiable traits. As traits continue to be identified, the key will eventually narrow it down to one species.

What information does a dichotomous key provide?

The species name based on identifiable traits, but it cannot provide the evolutionary history of a species

Taxonomy

The identification, naming, and classification of a species

Hierarchical Classification

The method of classifying organisms in which the ranks and the named taxons within them are arranged from least to most specific

Levels of taxonomy

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Domain

The most broad rank, in which organisms are classified according th their most ancient lineages and cell types; Bacteria, Archaea, and Eukarya

Kingdom

The second most general rank; Bacteria, Archaea, Protista, Plantae, Fungi, and Animalia

Example of a phylum

The phyla under Animalia include Arthropoda, Echinodermata, and Chordata

Example of a class

A class under Chordata are Mammalia

Example of an order

An order under Mammalia are Primates

Example of a family

A family under Primates are Hominidae

Example of a genus

A genus under Hominidae is Homo

Example of a species

A species under Homo is Homo sapiens

Characteristics of the domain/kingdom Bacteria

Prokaryotic

Unicellular

Has a cell wall made of peptidoglycan

Autotrophic (cyanobacteria) or heterotrophic

Asexual reproduction (Binary fission, conjugation, transformation, transduction)

Can sometimes be harmful, but are often beneficial to life

Characteristics of the domain/kingdom Archaea

Prokaryotic

Unicellular

Autotrophic or heterotrophic

Asexual reproduction

Extremophiles

Characteristics of the domain Eukarya

Eukaryotic

Have membrane-bound organelles, including a nucleus with DNA

Complex cellular organization

Characteristics of the kingdom Protista

Eukaryotic

Unicellular (Protozoa, Ciliophora) or multicellular (algae)

Cell wall made of cellulose or not present

Autotrophic or heterotrophic

Asexual or sexual reproduction

Role of protists

Plant-like protists, such as Diatoms, Pyrrophyta, and Algae are autotrophs, making them important sources of food and O₂

Animal-like protists, such as Cercozoa, Cilia, and Sporozoa, are food sources, and sometimes parasitic

Fungi-like protists, such as slime moulds, are decomposers of dead matter, waste, bacteria, and yeast

Characteristics of the kingdom Plantae

Eukaryotic

Multicellular

Cell wall made of cellulose

Autotrophic

Sexual reproduction

Characteristics of the kingdom Fungi

Eukaryotic

Multicellular

Cell wall made of chitin

Heterotrophic

Asexual or sexual reproduction

Characteristics of the kingdom Animalia

Eukaryotic

Multicellular

No cell wall

Heterotrophic

Sexual reproduction

Characteristics of living things

Homeostasis, levels organization, metabolism, growth, adaptation, response to stimuli, and reproduction

Cellular Respiration

The process by which cells use sugars and oxygen to create energy.

Cellular Respiration Equation

6O₂ + C₆H₁₂O₆ → 6CO₂ + 6H₂O + 36ATP

Photosynthesis

The process where autotrophic cells use carbon dioxide, water, and sunlight to produce sugars and oxygen

Photosynthesis Equation

6CO₂ + 6H₂O + sunlight → 6O₂ + C₆H₁₂O₆

Virus

A structure that contains strands of DNA or RNA surrounded by a protective protein coat; it cannot live independently outside of cells. It creates no waste, produces no energy, and has no membranes, organelles, or cytoplasm

Structure of a virus

Genetic material (RNA or DNA) and a protective protein capsid. Some may have spike proteins and tail fibres.

Function of a virus

They are infect cells and inject genetic material, where the virus parts and genetic material reproduce inside of a host cell.

Lytic Cycle

The replication process in viruses in which the virus’s genetic material uses the copying machinery of the host cell to make new viruses. The steps are:

Attachement of virus onto cell

Insertion of viral genetic material into cell

Replication of virus parts using the host machinery

Assembly of viruses

Lysis (viruses burst out of cell)

Example of a lytic cycle virus

Variola Virus - Smallpox

Lysogenic Cycle

The replication process in viruses, in which the viral DNA enters the host cell’s chromosome; it may remain dormant and later activate and instruct the host cell to produce more viruses. The process is:

Attachment and insertion of viral genetic material

Provirus formation (genetic material becomes part of the host DNA)

Lysogeny (dormancy)

Provirus separation

Replication and assembly

Lysis

Example of a lysogenic cycle virus

Human immunodeficiency virus (AIDS)

DNA Virus

A virus that inserts DNA into the host and deactivates mRNA of host. Viral genetic material intercepts the host’s process to create mRNA, and it instead uses the viral mRNA to replicate viruses.

RNA Retrovirus

A virus where retroviral RNA is inserted into host. The Reverse Transcriptase (enzyme) is activated, and it converts retroviral RNA into DNA. The new retroviral DNA splices into host chromosome and becomes dormant. The retroviral DNA is triggered and spliced out of the host DNA and becomes active. The host mRNA is deactivated, and retroviral mRNA is made using the host cell machinery. (Goes against the Central Dogma of Biology)

Central Dogma of Biology

DNA in the nucleus, through transcription, creates mRNA which leaves the nucleus, finds ribosomes, and makes proteins

Positive Control

Proves the viability of the experiment, showing that what should work in the experiment is working, and serves as a base for comparison

Negative Control

Proves the viability of the experiment, showing that nothing happens when nothing should be happening

Experiment Control

What the changed variable is testing for

Luria Broth

A nutritionally rich medium primarily used as food for the growth of bacteria

Ampicillin

An antibiotic that can kill Escherichia Coli bacteria

+ plasmid

The plasmid has been added to the bacteria

- plasmid

The plasmid has not been added to the bacteria

Plasmid

A small loop of DNA that is separate from the main chromosome, and contains different genes from the chromosome; they can join the chromosome or be transferred to another cell, making them an important part of genetic recombination

Bacterial Transformation

The transmission of genetic material where a DNA segment is picked up by a living bacteria, which can now perform the function of the DNA; in order for artificial transformation to work, the plasmid must be advantageous to the new cell, and selectable markers must be present to identify if the transformation works

Characteristics of the plasmid in the bacterial transformation lab

The plasmid is a fusion protein. It contains the GFP (green fluorescent protein) gene from bioluminescent jellyfish which creates a glowing protein, and the beta lactamase gene which gives the bacteria ampicillin resistance. The GFP is a reporting molecule that shows that the transformation has occurred.

Positive control plate in the bacterial transformation lab

LB- and LB+, because they show that the bacteria can viably grow with and without the plasmid present

Negative control plate in the bacterial transformation lab

LB/amp-, because it shows that no bacteria can grow in the presence of ampicillin without the ampicillin resistance gene, and it shows that the ampicillin is a viable antibiotic.

Experimental plate in the bacterial transformation lab

LB/amp+, because it tests if the bacteria have taken in the plasmid and been transformed, as shown by their resistance.

Expected results of the bacterial transformation lab

The LB- plate will have non-fluorescent bacteria only.

The LB+ plate will have both non-fluorescent and fluorescent bacteria.

The LB/amp- plate will have no bacteria present.

The LB/amp+ plate will only have fluorescent bacteria.

Steps of the bacterial transformation lab

• Add calcium chloride to each test tube (+ and -)

• Add bacteria to both tubes with an inoculating loop and vigorously spin

• Add the plasmid to the + tube, and incubate both tubes on ice for 10 minutes

• Heat shock both tubes for 90 seconds in warm water and then return to ice

• Add ampicillin to two out of four agar plates

• Add Luria broth to each test tubes, and incubate them

• Add the - tube bacteria to one plate with and one plate without ampicillin

• Add the + tube bacteria to different plates with and without ampicillin

• Clam shell the lids and spread the bacteria out with glass beads

• Incubate them for 24-36 hours at room temperature

Purpose of adding CaCl₂ in the bacterial transformation lab

It has a positive charge, so it can neutralize the negatively charged DNA, which allows it to easily pass into the negatively charges phospholipid heads of the membrane of the bacteria

Purpose of heat shock in the bacterial transformation lab

It allows the membrane to loosen, so the plasmids can easily be absorbed, and it helps the bacteria grow in volume

Purpose of Luria broth in the bacterial transformation lab

It is food for the bacteria to survive, allowing them to grow easier

Purpose of ampicillin in the bacterial transformation lab

It kills any of the bacteria that have not been transformed with the plasmid