Exam 4

Question 1

Define the term “Adaption” within Biological Evolutino

Answer 1

A characteristic that makes an organism able to survive and reproduce in its environment. Helps explain the diversity of life.

Question 2

Darwin vs. Lamarck’s proposal

Answer 2

Darwin: Living things change over time, evolution. Those with best traits survived and passed on those traits. (Natural Selection)

Lamarck: Species didn’t die out in extinctions, Lamarck claimed. Instead, they changed into other species. Living things evolved in a continuously upward direction

Question 3

What is the Fossil Record and how does it support evolution?

Answer 3

The Fossil Record is the history of life recorded by fossils. Most direct evidence that evolution has occurred, the species found in ancient rock are not species we see today. Record is complete enough to tell us that life has progressed from simple to complex.

Question 4

What are Transitional fossils within the Fossil Record?

Answer 4

Transitional fossils are those with characteristics of 2 different groups, they tell us who is related to whom and how evolution occurred.

Question 5

What does Biogeography study?

Answer 5

The study of distribution of plants and animals in different places throughout the world.

Question 6

How does Biogeographical Evidence support the theory of evolution?

Answer 6

Species on Earth being distributed around the planet based on their genetic relationships to each other. (Desert plants vary on different continents)

Question 7

How does Anatomical Evidence support the theory of evolution?

Answer 7

All vertebrate forelimbs contain same sets of bones organized in similar ways, despite their dissimilar functions; basic forelimb plan belonged to a common ancestor.

Question 8

What is a Homologous Structure?

Answer 8

Structures that are anatomically similar because they are inherited from a common ancestor.

Question 9

What is an Analogous Structure?

Answer 9

Serve the same function but are not constructed similarly; nor they they share common ancestry. (wings of birds & insects)

Question 10

What is a Vestigial Structure?

Answer 10

Anatomical features that are fully developed in one group of organisms but are reduced and may have no function in similar groups. (Whales have pelvis and legs)

Question 11

How does Biochemical Evidence support the theory of evolution?

Answer 11

All organisms have similar DNA, ATP and enzymes. Organisms use the same DNA code and 20 amino acids in their proteins. Many developmental genes are shared in animals ranging from worms to humans. Only slight difference in regulation of genes.

Question 12

Did humans evolve from apes?

Answer 12

No, they share a common ancestor and are considered cousins

Question 13

Define the Replacement Model within Evolution

Answer 13

Proposes that modern humans evolved from earlier Homo species only in Africa, and then migrated to Asia & Europe, where they replaced early Homo species about 100,000 years ago

Question 14

Examples of Human Variation

Answer 14

People have different ethnicities. Suspected human variations to adapt to local environment conditions: dark skin for high UV light areas, light skin for lower UV light areas.

Question 15

What is the Biosphere?

Answer 15

Portion of the Earth that contains living organisms, from the atmosphere above to the depths of the oceans below and everything in between.

Question 16

What is an Ecosystem?

Answer 16

Specific areas of the biosphere where organisms interact and contains the physical and chemical environment.

Question 17

What defines a terrestrial ecosystem, or biome?

Answer 17

Temperature and rainfall levels

Question 18

Define abiotic components of an ecosystem

Answer 18

The non-living components of the ecosystem, including sunlight, water, temperature, wind, and nutrients.

Question 19

Define biotic components of an ecosystem

Answer 19

Living organisms that can be categorized according to their food source, generally organized as autotrophs or heterotrophs

Question 20

Describe what happens during a Trophic Cascade within the environment and the food chain

Answer 20

An ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling.

Question 21

What is a Keystone Species within an Ecosystem?

Answer 21

A keystone species helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. Helps to keep populations under control (wolves, sharks, starfish, etc.)

Question 22

Define Bioaccumulation

Answer 22

Process by which toxins enter the food web by building up in individual organisms

Question 23

Define Biomagnification

Answer 23

Process by which toxins are passed from one trophic level to the next (and thereby increase in concentration) within a food web, ie., many organisms

Question 24

Define Reservoir vs. Exchange pool

Answer 24

Reservoir: source of chemicals unavailable to producers (carbon in shells on ocean bottoms)

Exchange pool: Source which organisms able to take chemicals (atmospheric or soil)

Question 25

Define what runoff is within the water cycle

Answer 25

Water that flows directly into nearby streams, lakes, wetlands, or the ocean.

Question 26

What are fossil fuels made of?

Answer 26

Plant and animal remains millions of years old, transformed into coal, oil, and natural gasses.

Question 27

Explain the Greenhouse effect

Answer 27

Nitrous oxide and methane act as panes of glass; allow solar radiation to penetrate to Earth but infrared rays can’t escape back into space.

Question 28

How is the growth rate determined within a population?

Answer 28

Number of people born per year vs. number of people who die per year.

Question 29

Define Nonrenewable Resources

Answer 29

They are limited in supply and eventually will run out (amount of land, fossil fuels, and minerals)

Question 30

Define Renewable Resources

Answer 30

Capable of being naturally replenished, a new supply will always be forthcoming (water, certain energy forms “solar energy”, harvesting plants and animals for food)

Question 31

Define Minerals

Answer 31

Nonrenewable raw materials in the Earth’s crust that can be mined and used by humans.

Question 32

Define Biodiversity

Answer 32

The variety of life on Earth and described in terms of the number of different species

Question 33

What are Alien Species?

Answer 33

Nonnative members of an ecosystem, usually introduced by humans.