Biology Final 2023

PBS Biology Honors Final Study Guide

Why do biologists organize things?

To organize things into groups that have biological meaning.

Who are systematists?

People who group and name organism based on studies of their different characteristics.

Who developed the classification system we usen today?

Carolus Linnaeus

What do the two words of the binomial nomenclature system identify?

Genus and species

What is the species name of humans?

*Sapiens*

What language do taxonomists use and why?

Latin, since it’s a dead language it never changes.

How do you write a scientific name?

Genus name capitalized, whole thing underlined.

How do you type a scientific name?

You use italics. Hooray!

What tool can anyone use to identify organisms?

A dichotomous key.

What is a dichotomous key?

It is a key made up of a set of numbered statements dealing with a set characteristic of an organism.

What is the smallest taxon?

Species

What is the largest taxon?

Domain

All the taxon in order from largest to smallest

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

What is evolution?

The process of change over time.

What are the three patterns of biodiversity noted by Darwin?

Species vary globally, locally, and over time.

What is artificial selection?

Nature provides variation within a species, and humans select those they find useful.

What are Darwin’s concepts that formed his theory?

1. Struggle for Existence
2. Variation and Adaptation
3. Survival of the Fittest

What is an adaptation?

Any heritable characteristic that increases an organism’s ability to survive and reproduce in its environment.

What is fitness?

How well an organism can survive and reproduce in its enviroment.

What is natural selection?

Process by which organisms with variations most suited to their local environment survive and leave more offspring.

What is phylogeny?

Evolutionary history of lineages.

What is a clade?

A group of species that includes a single common ancestor and all of the descendants living and extinct.

What is a monophyletic group?

Includes a single one common ancestor and all of its descendants.

What is a cladogram?

Links groups or organisms by showing how evolutionary lines, or lineages, branched off from common ancestors.

What are the two main characteristics that distinguish between the six kingdoms?

Cell Type/Structure and Method of obtaining energy

Which two kingdoms have prokaryotes?

Archaebacteria and Eubacteria

Are prokaryotes multicellular or unicellular?

Unicellular

How big are prokaryotes?

They are microscopic.

Are prokaryotes heterotrophs or autotrophs?

Prokaryotes are heterotrophs and autotrophs.

How do autotrophic protists gain energy?

They photsynthesize and chemosynthesize.

Where do archaebacteria live?

In extreme enviroments, often without oxygen

Where do Eubacteria live?

Eubacteria live everywhere except in extreme enviroments.

Are all Eubacteria harmful?

Not all Eubacteria are harmful. Some are harmless and even helpful.

What is the kingdom name for protists?

Protista

Where do protists live?

Protists live in moist environments.

Are protists unicellular or multicellular?

All protists are unicellular except for brown-algae.

Are protists heterotrophs or autotrophs?

Protists are heterotrophs and autotrophs.

Are fungi heterotrophs or autotrophs?

Fungi are heterotrophs

How do fungi move?

Fungi are non-motile (they don’t)

How do fungi gain energy?

They decompose dead things to obtain energy.

Are fungi multicellular or unicellular?

Fungi are multicellular

What is an example of a fungus?

A mushroom.

What is a virus?

A particle that causes disease in organisms.

Are viruses living?

Viruses are not living.

Why can’t viruses be living?

They don’t meet all of the characteristics of life.

What is the only thing a virus can do?

Replicate.

What is a host cell?

The cell in which a virus replicates

What is a bacteriophage?

A virus that only infects bacteria.

What is the core of a virus made of?

Nucleic acid

What is a capsid?

Protein coat of a virus that surrounds the nucleic acid core.

What is an envelope?

A protective outer layer made of lipids, proteins, qand carbohydrates.

What viruses have envelopes?

Animal-infecting viruses. AKA enveloped viruses

What is an example of an enveloped virus?

Human influenza

What two things does the protein arrangement of a capsid determine?

Shape and what the virus will infect.

How many viral shapes are there?

4

Rod-shaped virus

Long, narrow, and helical in shape. Ex: Tobacoo-mosaic virus

Polyhedral virus

Many sided, resemble small crystals. Ex: Polio

Enveloped virus

Capsid is encased with an envelope studded with projections. Ex: HIV

Head with tail

Infect bacteria and consist of a polyhedral head attached to a cylindrical tail with leg-like fibers.

How specific are viruses?

Very specific

Why is the specificity of viruses important?

Specificity is important for controlling the spread of disease.

How long is a typical lytic cycle?

30 minutes.

How many new viruses can be produced during the lytic cycle?

200

Lytic Cycle

Viral replication process that rapidly kills the host cell by causing it to lyse/burst

What are the phases of the Lytic Cycle in order?

1. Attachment
2. Entry
3. Replication
4. Assembly
5. Lysis and Release

Attachment (Lytic Cycle)

Viral proteins recognize and attach to the plasma membrane of the host cell.

Entry (Lytic Cycle)

The virus injects its nucleic acid into the host cell.

Replication (Lytic Cycle)

The viral nucleic acid takes over the metabolism of the host cell, forcing it to make viral nucleic acid and protein.

Assembly (Lytic Cycle)

The newly synthesized particles are assembled into viruses.

Lysis and Release (Lytic Cycle)

During this final step, the host cell ruptures and releases particles which will go out and infect other cells.

Lysogenic Cycle

The replication process where a virus does not immediately kill the host cell.

What are the steps of the Lysogenic Cycle in order?

1. Attachment and Entry
2. Provirus Formation
3. Cell Division
4. Lytic Cycle

Attachment and Entry (Lysogenic Cycle)

Virus attaches to the host cell and injects DNA

Provirus Formation (Lysogenic Cycle)

Viral nucleic acid becomes part of host cells chromosomes.

Cell Division (Lysogenic Cycle)

Inactive provirus replicates along with host cell’s chromosomes and host undergoes normal cell division.

Lytic Cycle (Lysogenic Cycle)

Provirus cuts loose from host cell’s chromosomes and the lytic cycle begins.

Provirus

Viral DNA injected into the host cell’s chromosome.

How long can the lysogenic cycle last?

Many Years

Spikes

Cover some envelopes, are made of proteins and carbohydrates, and enable viruses to recognize and attach to the cells they infect

Envelope

Made of lipids and proteins and carbohydrates, protective outer layers, and tend to be found in viruses which infect animals.

Nucleic Acid

Either DNA **or** RNA, **but not both**

Capsid

Protein coat of a virus that surrounds the nucleic acid core.

What are the two main groups of bacteria?

Eubacteria and Archaebacteria

Describe Eubacteria

“True Bacteria” all of the organisms traditionally known as bacteria.

Describe Archaebacteria

Live in unusually harsh environments.

How do Archaebacteria differ from other bacteria?

They live where nothing else can. They have cell walls, cell membranes, and rRNA.

Where do archaebacteria live (specifically)?

Extremely salty places, hot and acidic places, and in undersea volcanic vents.

Methanogens

Produce methane

Thermoacidophiles

Live in hot, acidic water

Extreme halophiles

Live in extremely salty conditions

Hans Christian Gram

Developed the Gram-Stain technique

Gram Stain Process

1. Stained with purple dye (Crystal Violet) and iodine.
2. rinsed in alcohol.
3. stained with red dye (saffreran)

What determines what color dye will be taken up during the gram-stain?

The cell wall structure

Gram Positive Bacteria

Have thick cell walls made up of sugarprotein. (Purple)

Gram Positive Example

Antibiotics and Antnomies (yogurt)

Gram Negative Bacteria

Have an extra lipid layer and appear pink after gram stain

Why is it important to know if bacteria are gram positive or negative?

Determines the type of antibiotics that should be used.

What are cyanobacteria?

Gram negative eubacteria that preform plant-like photosynthesis and release oxygen as a byproduct.

What are cyanobacteria also called?

Blue-green algae

Are bacteria prokaryotes or eukaryotes?

Bacteria are prokaryotes