Morphology
What type of diagram is based on morphological structures?
A dichotomous key
Define mutation
A mutation is a harmful, beneficial or neutral change in the DNA sequence of an organism.
What are the 4 nucleotide bases in DNA?
Adenine, Thymine, Guanine, Cytosine
What 2 scientists developed the theory of Natural selection in the 19th century (1858/1859).
Charles Darwin and Alfred Wallace
List 3 scientific concepts that are evidence for Evolution
Fossil Record
Comparative Anatomy/homologous structures
Genetics and Molecular Biology
Biogeography
Embryology
Define morphological structures
Morphological structures are the physical characteristics of an organism’s body, both external and internal, that help scientists Identify an organism, understand how it functions, and determine evolutionary relationships.
List 3 potential causes for mutation
Error in DNA replication
Radiation exposure
Chemical exposure
Define genetic drift
A random change in allele frequencies that occurs due to chance events, particularly in small populations.
State the theory of Natural Selection
Traits that enhance survival and reproduction become more common in a population over generations.
What is true of older fossils?
Older fossils are found in deeper rock layers, helping scientists establish evolutionary timelines.
Define homologous versus analogous structures
Homologous structures:similar anatomy, different function.
Analogous structures different anatomy, similar function.
List 3 mutations seen in humans
Lactose tolerance
Sickle cell anemia
Red hair
Cystic fibrosis
Color blindness
Widow's Peak
Albinism
Freckles
A population undergoes a sharp reduction in size, usually due to a disaster such as a fire or flood. The surviving population may have very different allele frequencies than the original population.
What animal did Darwin observe on Galapagos islands and what characteristic was being observed?
He observed various species of finches that has varying beak sizes and shapes dependent on their food sources and location.
What is said about the link between DNA and evolutionary relationships?
The more similar two species' genetic sequences are, the more closely related they are.
List 5 morphological structures that are common to the mammalian class
Four-chambered heart
Mammary glands
Diaphragm
Fur/hair
Bilateral symmetry
Live birth (except monotremes)
Endothermy (warm-bloodedness)
External ears
Highly developed brain (especially the cerebral cortex)
4 limbs
There are 3 types of point mutations. What are they and how do they differ?
Insertion: one nucleotide base is added somewhere within the DNA sequence.
Deletion: one nucleotide base is removed from the DNA sequence.
Substitution (most common): one nucleotide base is changed out for another.
What is the founder effect?
A small group of individuals breaks off from a larger population and establishes a new population in a different location. Because the group is small, it carries only a limited sample of the genetic variation found in the original population.
What are 3 human traits that have been phased out due to Natural Selection?
Wisdom teeth
Body hair
Larger Jaws
Enlarged Appendix
Acute sense of smell
Webbed fingers
Changed coccyx structure
Millions of years ago, Earth's continents were connected in a supercontinent called Pangaea. As the continents drifted apart, species were isolated, leading to distinct evolutionary paths. What is this called?
Continental Drift
In flowers, what are the main male and female reproductive structures called?
Male: the stamen is made up of the anther and filament.
Female: the pistil is composed of the stigma, style, and ovary
Why are mutations important for evolution?
Introduces variation, Enables adaptation, Feeds other evolutionary forces like natural selection and genetic drift.
Does genetic drift create variation? Explain
No — it only changes the frequencies of existing alleles. This is different from mutation where new genetic material is introduced.
Natural selection isn’t just about competition. It also involves cooperation, symbiosis, and adaptation.
How is cooperation different from symbiosis? Provide an example of each.
Both involve interactions between organisms.
Cooperation: when species evolve traits that benefit the group, not just the individual. This occurs within a group of common species. Ants cooperate within their colony for common goals of nesting, foraging and defending.
Symbiosis: Many species evolve close partnerships that improve survival. This occurs between different groups of species. Bees have a symbiotic relationship with flowering plants.
Developing embryos often show traits shared by evolutionary ancestors before they disappear. What are two examples of this seen in human embryos?
Pharyngeal arches
Tail-like extensions