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36 Cards in this Set

  • Front
  • Back
What is the first of the 8 major classification groups of the earth's known living organisms?
Darwin's theory of natural selection is mainly concerned with:
how adaptations evolve.
Biologists have identified _____ species in the world today.
1.5 million
What is a genus?
A group of closely related species.
What are the three levels of variation for the human population on earth?
-differences among individuals of the same race
-differences among family members
-differences among races
All members of the same species:
have the ability to reproduce with each other.
What is selective breeding?
selecting a desirable trait from the random variations that occur in the population.
What maintains the changes of the DNA in living organisms over time?
natural selection
What are some post-zygotic reproductive barriers?
reduced hybrid viability and fertility, and offspring of hybrids have reduced fertility or viability
What are breeds?
Individuals within one species that share many traits; they are developed artifically through selective mating.
Selective breeding is also called:
artifical selection
About how many generations of breeding are needed for a breeder to derive a population of individuals having the same traits?
10 to 15
How does adaptation occur?
Exploitation of biological niches through natural selection.
What are the 4 ideas of darwin's natural selection?
1. organisms produce a surplus of offspring and the members of a population differ from one another.
2. there is inheritable variation of the offspring.
3. organisms compete for limited resources and their differences affect how well it adapts to the environment.
4. individuals that are better adapted to their environment are more likely to survive and reproduce.
Why do living organisms undergo change?
mutation causes the change and natural selection maintains the change.
How does bacteria become antibiotic resistant?
They develop antibiotic resistance when they are exposed to antibiotics for a long period of time and through random mutation.
What is the basic unit of classification of biological organisms?
How many kingdoms are there?
_____ dominate the living world by their diversity.
How does a species come into being?
Individual variations and reproductive isolation.
How does reproductive isolation occur?
By geographical seperation of two populations of the same species.
What causes a species to become extinct?
Environmental Changes
What are the 7 groups in the classification system?
Kingdom, Phylum, Class, Order, Family, Genus, Species.
What is speciation?
A process in which two populations achieve reproductive isolation.
All life shares common:
biochemical, cellular, molecular, and genetic mechanisms
The Earth was formed ______ years ago.
4.5 billion
Early life formed ______ years ago.
3.8 million
The Earth was formed ______ years ago.
4.5 billion
Early life formed _____ years ago
3.8 billion
Prokaryotes appeared _____ years ago
3.8 billion
Eukaryotes appeared _____ years ago
2.5 billion
What is taxonomy?
The scientific classification of organisms.
The driving force behind allopatric speciation is:
geographical isolation and environmental change.
Mating Barriers
habitat isolation, behavior isolation, temporal isolation
Fertilization Barriers
mechanical isolation, gametic isolation
Hybrid Barriers
inviable hybrid, infertile hybrid, infertile offspring