BSC Unit 5

The Spanish flu infected one-third of the world's population, killing between ______ and _____ million people

30, 50

Which of these explains one of the processes by which the influenza virus evolves?

A mutation that changes the viral spikes is introduced into the genetic material.

Drag each characteristic to the method of influenza evolution it describes.

Antigenic drift --> Is the result of the introduction of mutation, Results in a change to the surface spikes of the influenza virus, Can be attributed to RNA polymerase inefficiency, May make the annual vaccine less effective and cause local outbreaks Antigenic shift --> Typically involves animal hosts, Poses a relatively greater threat, A host cell manufactures particles from two forms of the virus, Delays immune response and may cause an outbreak

Why is Archaeopteryx considered to be a transitional fossil?

Because it has features of both birds and dinosaurs

Which of these choices explains how the process of evolution relates to the study of biology?

Biology is the study of the natural world and the process of evolution is a part of that world.

Select all that apply. If you were to create a list to summarize the scientific evidence that supports the idea that populations evolve over time, which of these items would you include?

DNA molecules fossils homologous structures

Which of these offers an explanation of the relationship between biology and evolution?

Evolution is the unifying theme of biology. This process helps to explain nearly every aspect of the biological sciences.

In the quest to produce effective influenza vaccinations, what are the consequences of evolution in the virus?

Sometimes the vaccines are not effective because predictions about the path of the viral evolution don't hold up.

Which best describes the consequences of evolution on producing effective influenza viruses?

The process is more challenging because the virus evolves quickly.

Which of these explains one of the processes by which the influenza virus evolves?

Two different forms of the same virus infect the same host cell and a new virus is created with parts of each form.

Which of the following is a pair of analogous structures?

a butterfly's wing/ a bird's wing

Structures that serve the same purpose but evolved independently are called _____ structures.

analogous

Local influenza outbreaks are most likely the result of which mechanism of influenza evolution?

antigenic drift

Which method of influenza evolution can be attributed in large part to the efficiency of RNA polymerase?

antigenic drift

The evolution of a species is driven by genetic ________ , which can be passed from one generation to the next.

changes

Evolution, by its scientific definition, refers to

changes in a species or population over time.

The study of homologous and analogous structures, also called _________ anatomy , studies the similarity of both living and fossilized species' structures to infer evolutionary relationships.

comparative

Which type of selection favors both extremes, making the most common variant for a trait in a population detrimental?

disruptive selection

Antigenic ______ is a mechanism of influenza evolution that causes changes to the spikes on the viral surface.

drift

The influenza vaccine produced for the 2017-2018 flu season was only 30% effective because of an evolutionary mechanism called antigenic

drift

The influenza vaccine produced for the 2017-2018 flu season was only 30% effective because of an evolutionary mechanism called antigenic _________ .

drift

Global influenza outbreaks are most likely the effect of

evolution of the virus via antigenic shift.

The forelimbs of modern vertebrates are homologous structures, meaning that they may have changed evolutionarily to perform different functions, but they

evolved from the same body part in a common ancestor.

If a favorable mutation increases the ability of an individual to reproduce then natural selection would

favor this variation.

One of the components of the process of natural selection is based upon an individual's ability to compete for resources in order to survive and reproduce. This component addresses the

fitness of individuals.

Reproductive success among individuals with favorable traits, which they pass on to the next generation is often described using the term

fitness.

Evolution is the result of

genetic changes within a species or population over time.

Select all that apply. Which of these are possible consequences of antigenic shift in the influenza virus?

global outbreak a new combination of H and N spikes on the surface of the virus slow adaptation by the immune system

Categorize the structures that appear above as either homologous or analogous.

homologous --> dolphin flipper and wing of a bat analogous --> legs of a spider and legs of a dog

Structural similarities due to common descent are seen in

homologous structure

The evolution of a species is driven by

inheritable genetic changes.

When fossils are arranged and compared according to their age, from _________ to _________ , successive evolutionary change becomes apparent.

oldest, youngest

Select all that apply. Which of these are consequences of antigenic drift as it applies to the influenza virus?

reduced effectiveness of influenza vaccine local influenza outbreaks

One of the steps in the process of natural selection involves the individual's struggle to exist, which is based upon competition for available _________ like food and shelter

resources

Antigenic ________ is a mechanism by which the flu virus may evolve in such a way that slows the ability of the immune system to react, threatening widespread outbreak.

shift

Which type of selection favors the most common variant for a trait in a population?

stabilizing selection

Antigenic drift is a process that occurs when

there are changes on the surface spikes of the influenza virus because of mutations.

Fossils that provide some information about intermediate organisms between groups, like birds and reptiles, are called ______ fossils.

transitional

Antigenic shift is a process that occurs when

two different forms of the influenza virus infect the same host cell, which reproduces elements of both virus to create a new form.