Chapter 25-26

most viruses have _____ but do nt have

capsids/envelopes

The shape of the viruses is determined by the

capsomers

Phylogenetic tree that uses clades to show evolutionary relationships is called a ______.

cladogram

according to ____ hypothesis, viruses appeared early in the history of life, even b4 three domains diverged.

coevolution

homoplastic structures are a result of ______ evolution.

convergent

_____________ describes the independent evolution of similar structures in distantly related organisms.

convergent evolution

____________ is the study of diversity and of organisms and their evolutionary relationships.

Systematics

when faced with multiple possible cladograms the criteria of ____ is employed

parsimony

The phenetic system is based primarily on:

the number of shared characteristics

TAxanomy is the science of:

naming,describing, and classifying organisms

shared ancesteral charcters may also be called:

plesiomorphic charcters

The specificity of viruses to diffrent types of cells is due to _____ sites on the host cell.

receptor

features that appeared a long time ago and remained in the in the descendants of that organisms are called ___________.

shared ancestor characteristics

THe worldwide variety of oranisms and ecosystems is termed:

biodiversity

In 1969 RH Whittaker proposed a 5 kingdom classification based mainly on?

cell structure and how an organism derived nutrition

temperate viruses:

do not always destroy their hosts

human viruses can enter human cells by fusion with the cells membrane or by:

endocytosis

viral infecitons in humans spread via the circulatory system. iral infections in plants spread from cell to cell via:

plasmodesmata

viruses have all the following EXCEPT:

have mitochondria

Viral DNA that is intergrated into host DNA is called a ______ and bacterial cells carrying intergrated viral DNA are called _______

prophage-lysogenic cells

RNA viruses called _____ transcribe their RNA into a DNA strand.

retroviruses

gene swapping between organisms in one taxon and related organisms in another taxon is called ______________________.

horizontal gene transfer

viruses were first identified:

because they caused an infection and were small enough to pass through filters that trapped bacteria.

according to the _________ hypthesis viruses may have originated as mobile genetic elements such as transposons or plasmids.

cellular orgin

Bears and dogs are

chordates,mammals, and carnivores

virulent phages

destroy bacteria

Phages are being considered for:

antibiotics in bacterial infections

a symptom of a transmissable spongiform encephalopathy is:

degenerative of the brain and central nervous system.

Viroids are generally found within the host cell ________ and appear to interfere with ________.

nucleus, gene regulation

The original two kingdoms that were established to organize living organisms were_________.

plantae and anamalia

features that occured in a recent common ancestor and remain in the descendants of that organism are called ___________.

shared derived characters

when the organisms in a given taxon do not share a common ancestor the group is said to be _____________.

paraphyletic group

viruses that cause diseases

pathogens

comparison of ______ has been recently used to support the hypothesis that fungi are most clsley related to animals than to plants.

ribosomal RNA sequences

an example of homologous structures is the wing of a bat and:

the arm of a human

IN Linnaeus taxanomy is closley related species are assigned to the same genus, and closley related genera are grouped into

families

the two types of reproductive cycles observed amounf viruses are ____ and _____

lytic-lysogenic

a taxon that includes all the descendents of an ancestor is called:

monophyletic

When organisms in a given taxon include the ancestoral species and all of its descendants, the group is said to be _____________.

monophyletic group

The Broadest most inclusive group is called a _____

Domain

the evolutionary history of a group of organisms form a common ancestor is termed

phylogeny

which classification level would be the most inclusive

phylum

When the organism in a given taxon do not include all the descendants of an ancestoral species __________.

polyphyletic group

viroids cause a variety of plant diseases and are composed only of:

strands of RNA

the variety of living organisms and ecosystems is referred to as ___________.

Biodiversity

_______ developed the binomial system of nomenclature.

Carolus Linnaeus

Some biologists are considered adopting a diffrent classification scheme based on common ancestors called:

Phylocode

Before the developmental of microscope, organisms were only placed in to a kingdom ______ or __________.

Plantae or Anamalia

The first kingdom to be recognized beyond plantae and anamalia was:

Protista

viroids are hardy and resist heat and ultraviolet radiation because of the condensed folding of their ______.

RNA

_______ is credited with the discovery of prions as a new biological principle of infection

STanley Prusiner

the scientific study of the diversity of organisms and the evolutionary relationships between them is referred to as:

Systematics

The term clade most closley refers to:

a group of organims that share common characteristics inherited from a common ancestor

viruses are classified by:

an international committee

a taxon that diverges earlier than the other taxa being considered in acladistic analysis is

an outgroup

Viruses:

cannot ind. perform metabolic activities

the protein coat of a virus is called the:

capsid

Phylogenetic systematics produces branching diagrams called:

cladograms

the bacterium that causes botulism disease is harmless until it:

contains a certain prophage DNA

a ______ character is a trait that has evolved relatively recently.

derived

closley related or similar species are grouped into a single:

genus

Retroviruses differ from other RNA viruses by:

having reverse trans. instead of RNA dependent RNA polymerase

which of the following diseases is not caused by a virus

herpes virus

a cladogram is based on:

homologous characteristics

Viruses can be classified based on the type of organisms they infect or on their

host range

a prophage

is phage DNA that is intergrated into bacterial DNA

_____ conversion occurs when a bacterium carrying viral genes takes on new atypical characteristics.

lysogenic

IN the late 1970's Woes argued that Prokaryotes account for 2 or 3 major branches of organims because:

of diffrences in sequence analysis of 16sRNA of difrent group of prokaryotes

an _______ is a taxon that is considered to have diverged earlier than the taxa under investigation.

outgroup

viral proteins can damage host cells by:

overwhelming the host cell with large numbers of viruses

The principle_________ is based on the experience that the simplest explanation is probably the correct one.

parsimony

viruses that attack bacteria are called:

phages

Mad cow disease is an example of an infection caused by a:

prion

according to the ______ hypothesis, viruses evolved from small independent cells that were parasites in larger cells.

regressive

the five stages of a lytic infection are attachment, penetration, _______, assembly, and release.

replication

the DNA polymerase used by retroviruses in transcription is called_________.

reverse transcriptase

the genome of most plant viruses consist of _________

single strand RNA

Satellites are ____ agents that depend on co infection of host cell with a helper virus

subviral

Prions are found in the brains of patients with fatal degenerative brain disease called:

transmissable spongiform encephaiopathies

Genes are transmitted from parents to offspring in a process called _______.

vertical gene transfer

viruses that have only lytic cycle are said to be ______

virulent

Most biologist recognize ____ domains

3

viruses range from size _____ to _____ nm

20-300

scientist using evolutionary systematics to construct a phylogenetic tree would use:

a combination of ancestoral and derived characters