life science final exam (4) Flashcards
(51 cards)
Codominance occurs when…
Both maternal and paternal alleles contribute equally and separately to the phenotype
Which of the following is not a polygenic trait?
A. blood type
B. height
C. skin color
D. hair color
A. blood type is codominance
Males typically have higher levels of the hormone ______ than females.
Testosterone
What pattern of natural selection has occurred when phenotypes of a population are at both extremes of a range?
Disruptive Selection
Is the change in the average woman’s dress size from size 8 to size 14 over time considered an evolutionary change?
No, because it is due to women consuming a higher calorie intake, which is not geneti
Tuna and penguins both developed football-shaped bodies for better hydrodynamic efficiency. What concept does this best represent?
Convergent evolution
Which is not an example of a vestigial trait?
A. Humans and great apes having tailbones
B. Whales having functionless femurs and pelvises
C.Ostriches and penguins having wings, despite being flightless birds
D.Humans having opposable thumbs
D.
________ describes similarities due to common ancestry, while _______ describes organisms that are not closely related developing similar adaptations due to similar environments and challenges.
Homology; convergent evolution
How are fossils dated?
Relative and radiometric dating only
Is the fossil record a complete record of past life on Earth?
No, since not all organisms are preserved or leave behind a trace
What is evolution?
Change in the characteristics of a population of organisms that occurs over generations
Pesticide resistance in crop-eating organisms and antibiotic resistance in infectious bacteria are examples of:
Microevolution
About 65 million years ago, an asteroid approximately 6 miles across hit Earth, eliminating many organisms and causing a shift in allele frequencies in many populations. What type of nonadaptive evolution does this event display?
Genetic Drift
Which of the following conditions is not needed for a trait in a population to evolve?
A. The trait is heritable
B. Genetic variation in the trait within the population
C. Individual fitness varies depending on the trait
D. The trait must be favorable for the health of the organism
D.
To follow the visual representation of the occurrence of phenotypes across generations, you can examine a:
Pedigree
Antibiotic-containing environments favor resistant strains of bacteria, meaning that the environment selects for phenotypes towards one end of the spectrum. What type of selection is being displayed?
Directional Selection
Oxygen began to accumulate in Earth’s atmosphere about 3.0-2.5 billion years ago. This creation of oxygen was directly related to the emergence of:
Unicellular photosynthetic organisms
Humans’ skin tone (dictated by Melanin, a pigment in skin cells) began to change drastically when our ancestors migrated from Africa millions of years ago.Variability in skin tone is an organism’s direct adaptation to:
Local solar conditions
A trait not selected for in Homo sapiens is…
Quadrupedalism
When extremes of the phenotypic range fare worse than phenotypes in the middle of the traits range (favoring the “moderate” or “middle” phenotype)
Stabilizing Selection
When extremes of the phenotypic range fare better than phenotypes in the middle of the traits range (favoring both extremes)
Disruptive Selection
Favoring 1 phenotype
Directional Selection
What is the movement of alleles from one population to another existing population?
Gene flow
What is the change in allelic frequencies purely by chance
Genetic drift
