Study Guides (380,000)
US (220,000)
Rutgers (3,000)
2:59 (300)
Study Guide

01:119:116- Midterm Exam Guide - Comprehensive Notes for the exam ( 22 pages long!)


Department
Biological Science
Course Code
01:119:116
Professor
G.Transue
Study Guide
Midterm

This preview shows pages 1-3. to view the full 22 pages of the document.
Rutgers
01:119:116
MIDTERM EXAM
STUDY GUIDE

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

General Biology II
Classification and Virology
Brief review of General Biology I
memory≠learning
o learning= the application of memory/knowledge via long term potentiation, learning allows one to increase the probability of positive
outcomes occurring, allows one to decrease the probability of negative outcomes occurring
o long term potentiation= lasting increase in synaptic strength and transmission, LTP is activity dependent
Diversity and Systems within the context of Evolution
I. Classification and Evolution
A. Classification: the way in which we structure and organize the world as a means of understanding the world
1. Systematics: is known as the scientific study that is dedicated to studying the diversity of organisms and the evolutionary
relationships between these organisms, there exist two branches of Systematics
a. Phylogenetics is one the two branches in systematics…it accounts for the ‘evolutionary relationships’ part of the
definition of systematics
b. Taxonomy is the other of the two branches in systematics…it accounts for the ‘diversity/multitude of organisms’
that exist in this world, it deals with the description of the organism
1. How does Taxonomy help us describe organisms?
a. Binomial Nomenclature: each species has a unique 2 part name–– Genus + specific epithet
i. ex. Homo sapien
2. How are organisms classified?
a. taxonomy helps us arrange organisms in increasingly inclusive (more and more species are
included) categories…depending how you look at it> creating a hierarchy
i. Domain Kingdom Phylum Class Order Family Genus Species (left to right:
increasingly exclusive | right to left: increasingly inclusive)
ii. taxon= grouping at any level on the taxonomical hierarchy… all species in a
specific taxon/level share characteristics of that group
1. ex. all species in Phyla A = milk production
all species in Phyla A, Class B= milk production & fur
all species in Phyla A, Class C= milk production & naked, but ≠ milk & fur (fur is a
characteristic of Class B)
A. Evolution: the accumulation of genetic changes in a population over time, when there exists a change in allele frequencies in a
population overtime, then we know that evolution has occurred…remember, Natural Selection may act on individual, but individuals do
not evolve!
1. Natural Selection= the mechanism of evolution, this is how evolution occurs, Natural Selection acts on individuals, especially
diverse individuals (picks and chooses the fittest variation)…Natural Selection will eventually lead to the preservation of some
variations, and the elimination of other variations
B. Basics of Phylogeny: phylogeny refers to the evolutionary history of organisms, the historical/evolutionary relationships between
organisms are established through phylogeny
1. Phylogenetic Tree: shows patterns of descent of the latest species, phylogenetic trees are NOT formed based on
phenotypic/physical similarities between organisms…phylogenetic trees are merely hypotheses of the evolutionary
relationships between organisms, and because they are hypotheses, their validity may be tested in a lab
a. a proper phylogenetic tree should be: a series of dichotomies (two branches), not based on phenotype
1. Components of a Phylogenetic Tree:
a. Branch Point/Node= the point of divergence of two evolutionary lineage from a common ancestor (CA)
b. Sister Taxa= the two branches that diverged from a common ancestor, they are each other’s closest evolutionary
relative
c. Basil Taxa= the lineage that diverged early in the history of the group, we can find the basil taxa on a branch that
originates most closely to the overall Common Ancestor
d. Polytomy= the branch point from which more than two groups diverge, when it is no longer a dichotomy, more than
two…this often indicates that at this point on the phylogenetic tree, we are lacking sufficient information required
to make the dichotomy/proper evolutionary relationship
e. Extant Species= the species that are found at the tips of the branches on the phylogenetic tree, indicates that these
species are currently still living
B. Biodiversity/Biological Diversity: all species compose the Tree of Life
1. the 3 Domains of life (remember, Domain is the most inclusive taxa on the hierarchy of life):
a. Domain Bacteria–– Prokaryotes
b. Domain Archaea–– Prokaryotes
c. Domain Eukarya–– Eukayotes
2. side note: why are there no Viruses on the Tree of Life? because Viruses are NON LIVING PARTICLES!
II. Virology
A. General Characteristics of Viruses:
1. Viruses are nonliving particles
2. Viruses are not cells
a. because viruses are not cells, they do not have a nucleus, cytoplasm, nor organelles
b. they cannot carry out metabolic activities on their own…they must rely on a host cell in order to replicate/undergo
metabolic processes
3. Viruses are Obligate (must) Intracellular (be inside) Parasites (and do harm to the host cell in order to survive)….in other
words, viruses can survive only by being inside the host cell and by utilizing the host’s organelles/materials as their resources
for their own viral replication and survival
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

General Biology II
Classification and Virology
4. Viruses replicate rather than reproduce (they multiply) inside of the cell (they are ‘intracellular’)…viruses replicate by
exploiting the host cell
5. Viruses are very small we cannot use a light microscope to see them, about 20-300 nm
6. Viruses have Genetic Material despite being nonliving, noncellular, and so small…viruses do have their own set of genetic
material in the form of either DNA or RNA (single or double stranded, linear or circular or segmented)
a. 3~100 genes are found on the viruses DNA/RNA…and all of these genes deals with the viruses replication process
while in the hose cell….as you can see, viruses are really driven to replicating inside of their host
B. Structure of Viruses: the structure of viruses may vary, but all have certain fundamental components
1. Capsid= all viruses have a capsid, the capsid is the protein coat that surrounds the viruses genetic material (the viruses DNA
or RNA)
a. Capsomere= all viruses have capsomeres, which compose their capsid…the protein subunits that compose the
capsid, plays a role in the viruses shape, which will in turn affect how the virus attaches to its host cell
2. Envelope= some viruses have an envelope…this envelope is a phospholipid bilayer that is often acquired from while
entering/exiting the host cell (which has its own phospholipid bilayer)…so basically, as the virus enters/exits/attacks the host
cell, it acquires some of the host’s plasma membrane for itself
a. the virus oftentimes acquires this envelope during Exocytosiswhile the virus is leaving the host cell, after it has
finished replicating its genetic material in the host cell
b. this membrane will include phospholipids & membrane proteins from the host cell
c. the virus may already have its own glycoproteins/proteins
C. Viral Replication:
1. Introduction to Viral Replication:
a. Host Range= refers to the range of host species that a particular virus can infect, host ranges are typically narrow
1. ex. host range for virus measles: only human hosts
ex. host range for west nile virus: humans, birds, horses, mosquitoes, etc.
a. Viruses are generally limited to specific tissues of multicellular eukaryotes
1. ex. the cold virus has a host range of only humans, but more specifically attack the tissue on the upper
Respiratory tract
b. *So why viruses so picky and specific? because….the interactions between viral surface and the host cell surface is
very specific… there exist specific receptor molecules on the host cell surface that the virus can attach to…like a
“lock and key” fit
2. Basic Features of Viral Replication:
a. Binding: First, the virus must bind/attach to the host cell
b. Entrance of the Viral Genome: then the viruses genetic material must enter the host cell, the specific manner
through which any given viruses genome enters the host cell will vary according to the specific virus itself
1. ex. some viruses genome enters via injection, endocytosis, fusion (enveloped viruses fuse with the host
cell’s plasma membrane)
c. Viral Proteins begin to take over: now that the viruses genome has entered the host cell, it is now equipped with
the proper directions on how the viral proteins can take over the host cell’s machinery…during this process
1. *The host cell is forced to copy/replicate the viral genome, producing more viral proteins*
d. Spontaneous Assemblage: now that the host cell has been manipulated into reproducing viral proteins due to the
injected viral genome/information/directions, viral nucleic acids and viral capsomeres (the viral protein subunits)
spontaneously assemble into a new viral particle in the host cell
1. Viral Nucleic Acid + Capsomere = New Viral Particle inside Host Cell
e. Exit the Host Cell: the newly created Viral Particles can now leave the host cell, exiting the host cell often results
in damage/death of the host cell :(
There exists two ways in which a Virus can Replicate itself:
1. Lytic Cycle: one of the two ways in which a Virus can Replicate itself, it will end in the death/destruction of the host cell,
viruses that undergo the Lytic Cycle are said to be “virulent phages”
a. How Bacteriophages undergo the Lytic Cycle: recall, Bacteriophages are viruses that invade Bacterium
1. First, the bacteriophage attaches to the Bacterium host cell
2. the bacteriophage then enters the host cell and begins to degrade the host DNA
3. the bacteriophage’s viral genome and viral proteins begin to synthesize
4. spontaneous assembly of more phage particles occur
5. Lytic Enzymes are produced during this replication processes. Phages are released from the host cell, and
these lytic enzymes destroy/even kill the host cell in the process
a. *Hence the “Lytic Cycle” ~ “Lysis” of host cell
b. Bacterial Defenses Against Bacteriophages: What is the evolutionary advantage behind the Lytic Cycle if it kills
the bacterium host cells?
1. A Bacterium’s Defense Against Bacteriophages 1: As you know, Natural Selection will favor those
bacterial mutants that do NOT have the surface receptors that are recognized by the
bacteriophage/virus…that way viruses cannot detect and then attach to these bacterium
2. A Bacterium’s Defense Against Bacteriophages 2: Restrictive Enzymes in the Bacterium host cell
recognize the foreign DNA of the bacteriophage/virus and cut up the virus/invader
a. These Restrictive Enzymes are able to only attack the Bacteriophage’s DNA because the
actual Bacteria//host cell’s DNA is methylated, which protects the bacteria’s DNA from lysis
2. Lysogenic Cycle: the second way viruses may undergo replication, the Lysogenic Cycle offers the virus an opportunity to
replicate without destroying the host cell…now, this doesn't mean that Lysis of the host cell is impossible after undergoing the
Lysogenic Cycle… it merely provides an opportunity for the host cell to be spared
find more resources at oneclass.com
find more resources at oneclass.com
You're Reading a Preview

Unlock to view full version