Unifying Themes & Biological Hierarchy

Question 1

What is scientific theory?

Answer 1

an explanation of some aspect of life based on facts, experimentation, and evidence

Question 2

What are the 2 elements of scientific theory?

Answer 2

1. Pattern
2. Process

Question 3

What is cell theory?

Answer 3

1. All organisms are made of cells
2. All cells came from pre-existing cells

Question 4

What does the cell theory tell us about life?

Answer 4

Life is continuous: The cells of an organism came from a single fertilized egg, which came from the parent’s gametes’, etc.

Question 5

What is evolutionary theory?

Answer 5

1. Evolution explains variation, how that variation occurred and what can happen if environmental conditions change.
2. All species are related through common ancestry.

Question 6

What is the connection between cell theory and evolutionary theory?

Answer 6

Cell theory states that all cells come from pre-existing cells, thus all organisms must be descended from a common ancestor.

Question 7

What is evolution?

Answer 7

The heritable/genetic change in a population over time

Question 8

What is the mechanism for evolution?

Answer 8

Natural selection rules evolutionary change.

Question 9

What is the biological hierarchy?

Answer 9

1. The organization of life
2. atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere.

Question 10

What are the 3 important elements of the biological hierarchy?

Answer 10

1. There is similarity between individuals within each level of the hierarchy.
2. The units of one level of the hierarchy define the next.
3. Emergent properties

Question 11

What is an emergent property?

Answer 11

A collection of units at 1 level take on a trait that is greater than the sum of the parts

Question 12

Explain how reproduction is an emergent property of both the organismal and population levels.

Answer 12

1. Organ systems, themselves, cannot reproduce but an organism has the ability to. Asexually reproductive organisms are able to use their organ systems to reproduce. It’s the units of one level (organ systems) gathering to take on a trait/action greater than themselves.
2. Many sexually reproductive species require two organisms for reproduction. Thus, a (small) population of species is required for reproduction. It is the collection of multiple units (multiple organisms) in a level to take on a trait/action that is greater than the sum of the parts.

Question 13

What are communities?

Answer 13

Collections of populations of different species living together in one area. Boundaries of this area may be set up by natural structure (e.g. shorelines) or arbitrarily determined by us.

Question 14

What are ecosystems?

Answer 14

Ecosystems are communities plus abiotic factors.

Question 15

What is the biosphere?

Answer 15

The collection of all the ecosystems.

Question 16

What is the relationship between natural selection, evolution, individuals, and populations?

Answer 16

Natural selection acts on individuals. Those selected individuals are part of a population that evolves as a result of natural selection.

Question 17

What is the importance of the term “nested hierarchy”?

Answer 17

Changes at each level affect the next level. If a change occurs at the organismal level, then it will affect the population level, then the community level, and then the ecosystem level.

Question 18

What is biological fitness?

Answer 18

The amount of offspring you can produce, or the amount of genes you can get into the next generation

Question 19

What is social vigilance?

Answer 19

An emergent property of the population level, that allows populations to watch out for each other.

Question 20

How does energy flow fit into the biological hierarchy?

Answer 20

Energy flow fits into the ecosystem level because energy flows through both abiotic and biotic factors.

Question 21

What is a biome?

Answer 21

A collection of similar ecosystems.

Question 22

Why aren’t biomes a part of the biological hierarchy?

Answer 22

Biomes don’t have any emergent properties.