2 - Connectivity and Diversity of Life

Question 1

What are viruses?

Answer 1

acellular infectious agents

Question 2

How do viruses reproduce?

Answer 2

Use a host cell’s machinery, energy and building blocks

Question 3

What is a virus’ structure?

Answer 3

organized structure made up of organized macromolecules

Question 4

What encloses a virus’ DNA or RNA?

Answer 4

protein capsules

Question 5

What are many human viruses enclosed in?

Answer 5

lipid membrane

Question 6

Why do mutations that allow viruses to be more successful arise?

Answer 6

because viruses have genetic material (DNA or RNA) encoding their structure

Question 7

What are the steps of viral reproduction?

Answer 7

1) uses its’ host cells replication system to make more copies of itself
2) bind to specific receptors on the host cells’ surface
3) insert their genetic material (RNA or DNA)
4) viral genetic material then gets inserted into the host cell’s DNA

Question 8

What do viral genes do once they take over common of the cell?

Answer 8

instructs cell to make more copies and once cell is full with copies, they are released or the cell ruptures releasing copies to infect other cells

Question 9

What factors would affect the entire food web within an ecosystem?

Answer 9

• link becomes scare or overabundant
• changes in physical environment

Question 10

What types of interaction exist in an ecosystem?

Answer 10

1) Between individuals of same species
- Competition for resource and mates; cooperation
2) Between individuals of different species
- Competition for food and resources, herbivory, predation, parasitism, mutualistic symbioses
3) With physical environment
- weather conditions, seasons, availability of resources

Question 11

What happens to energy in a system within an ecosystem?

Answer 11

Energy is lost from the system as it moves through the web in the form of heat

Question 12

What is the energy web in an ecosystem like?

Answer 12

producers: convert light energy and chemical energy
consumers: east chemical energy from producers and/or other consumers
decomposers: obtain energy from absorption of organic molecules from dead organisms or their tissues

Question 13

What happens to nutrients in an ecosystem?

Answer 13

nutrients are never lost

Question 14

What is the nutrient web in an ecosystem like?

Answer 14

physical environment: reservoir for water and nutrients
producers: assimilate nutrients from physical environment and use it to grow and develop
consumers: ingest nutrients from producers and/or other consumers to grow and develop
decomposers: breakdown complex organic molecules into simpler inorganic forms

Question 15

What are genes?

Answer 15

specific segments of DNA that hold instructions to make one or a few proteins

Question 16

What is each protein responsible for?

Answer 16

one or more traits within an organism

Question 17

What is evolution?

Answer 17

descent with modification in characteristics; changes in genetic traits with successive generations

Question 18

What is vertical descent?

Answer 18

New species evolve from pre-existing species through the accumulation of new beneficial mutations which are passed down from one generation to the next over a long period of time

Question 19

What are mutations?

Answer 19

errors that occur each time a cell divides a copy of every gene

Question 20

What is natural selection?

Answer 20

Mutation will become more prevalent and passed down if it allows the organism to survive and reproduce better

Question 21

What is horizontal gene transfer?

Answer 21

Evolution through the exchange of genes between 2 different species that happens within lifetime of the organisms

Question 22

What type of organisms is horizontal gene transfer most commonly between?

Answer 22

unicellular

Question 23

What type(s) of evolution has diversity evolved through?

Answer 23

both vertical descent with mutation and horizontal gene transfer

Question 24

What do taxonomists do?

Answer 24

Use a hierarchical system to group organisms with similar characteristics together

Question 25

What are the 8 levels of classification?

Answer 25

1) Domain
2) Kingdom
3) Phylum
4) Class
5) Order
6) Family
7) Genus
8) Species

Question 26

How are species organized?

Answer 26

Species are placed into progressively smaller groups of organisms that are believed to be more closely related to one another evolutionary