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Questions and Answers
Variation within a population is solely caused by mutations.
Variation within a population is solely caused by mutations.
False (B)
Which of the following processes contribute to the generation of variation within a population? (Select all that apply)
Which of the following processes contribute to the generation of variation within a population? (Select all that apply)
Explain how crossing over contributes to genetic variation.
Explain how crossing over contributes to genetic variation.
Crossing over is the exchange of genetic material between homologous chromosomes during meiosis. This process shuffles alleles, creating new combinations of genes and increasing diversity within a population.
The process of ______ refers to the random separation of homologous chromosomes during meiosis, leading to different combinations of alleles in gametes.
The process of ______ refers to the random separation of homologous chromosomes during meiosis, leading to different combinations of alleles in gametes.
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Match the following concepts with their descriptions:
Match the following concepts with their descriptions:
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What is the effect of the distance to the smelter on hair density in honeysuckle?
What is the effect of the distance to the smelter on hair density in honeysuckle?
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Stomata density in sandwort plants increases with the distance from the smelter.
Stomata density in sandwort plants increases with the distance from the smelter.
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Which of the following statements is supported by the data presented in Figure 16.7? (Select all that apply)
Which of the following statements is supported by the data presented in Figure 16.7? (Select all that apply)
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Based on Figure 16.7, describe the relationship between distance from the smelter and stomata density in sandwort plants.
Based on Figure 16.7, describe the relationship between distance from the smelter and stomata density in sandwort plants.
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What plant species was the main focus of the study?
What plant species was the main focus of the study?
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Stomata density was found to be higher in plants collected closer to the smelter.
Stomata density was found to be higher in plants collected closer to the smelter.
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What were the types of pollution analyzed in the soils surrounding the smelting operation?
What were the types of pollution analyzed in the soils surrounding the smelting operation?
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The legs of the smelting operation are located in __________.
The legs of the smelting operation are located in __________.
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Match the following measurements with their respective locations of plant collection:
Match the following measurements with their respective locations of plant collection:
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What impact did the researchers aim to study regarding the smelting operation?
What impact did the researchers aim to study regarding the smelting operation?
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Stomata and hair densities of honeysuckle were collected at only one time.
Stomata and hair densities of honeysuckle were collected at only one time.
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What method did the researchers use to grow the honeysuckle seeds?
What method did the researchers use to grow the honeysuckle seeds?
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What does hair density do with increasing distance from the plant?
What does hair density do with increasing distance from the plant?
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There is no genetic component to the differences in hair densities observed in honeysuckle.
There is no genetic component to the differences in hair densities observed in honeysuckle.
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What do common garden experiments demonstrate about sandwort and honeysuckle?
What do common garden experiments demonstrate about sandwort and honeysuckle?
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What is the main focus of the predator exclusion experiment?
What is the main focus of the predator exclusion experiment?
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Hair density __________ with distance from the plant.
Hair density __________ with distance from the plant.
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The presence of a snail predator can lead to developmental changes in acorn barnacles.
The presence of a snail predator can lead to developmental changes in acorn barnacles.
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Match the shell types with their descriptions:
Match the shell types with their descriptions:
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What factor is being studied in relation to hair density in plants?
What factor is being studied in relation to hair density in plants?
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Match the following organisms with their respective phyla:
Match the following organisms with their respective phyla:
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Common garden experiments can show both genetic and environmental influences on plant traits.
Common garden experiments can show both genetic and environmental influences on plant traits.
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Which of the following might be a result of predator exclusion on acorn barnacles?
Which of the following might be a result of predator exclusion on acorn barnacles?
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The bent shell shape of acorn barnacles develops in the absence of predators.
The bent shell shape of acorn barnacles develops in the absence of predators.
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What does the term 'genotype' refer to?
What does the term 'genotype' refer to?
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Phenotype refers to the genetic makeup of an organism.
Phenotype refers to the genetic makeup of an organism.
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What does the term 'environmental gradient' mean?
What does the term 'environmental gradient' mean?
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The _____ experiment is used to study genetic diversity by planting different populations in the same environmental conditions.
The _____ experiment is used to study genetic diversity by planting different populations in the same environmental conditions.
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Match the following terms with their definitions:
Match the following terms with their definitions:
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Which of the following statements about phenotype variation caused by the environment is true?
Which of the following statements about phenotype variation caused by the environment is true?
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Plants grown from seeds in different populations will have the same height if they are genetically the same.
Plants grown from seeds in different populations will have the same height if they are genetically the same.
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What is indicated by plants being different colors in a Common Garden Experiment?
What is indicated by plants being different colors in a Common Garden Experiment?
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Variation that occurs in populations is due to both _____ and environmental factors.
Variation that occurs in populations is due to both _____ and environmental factors.
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Study Notes
Integrating Concepts in Biology - Chapter 16: Variation and Population Genetics
-
Section 16.1: What Causes Individual Variation?
- Biology learning objectives include evaluating variation generation in organisms, its population-level impact, and its link to natural selection. Also, differentiating between independent assortment and crossing over is important.
Review
- Genotype: The genetic makeup of an organism.
- Phenotype: An observable trait. The phenotype is influenced by the genotype and the environment.
Individual Variation
- Individuals make up populations.
- Populations of organisms can show variation (differences) in many traits (phenotypes).
Variation
- Variation is a distinct form or version of something.
- Variations can be genetic (inherited) or environmental (acquired).
- Genotype/environment --> phenotype
Variation Caused by the Environment
- Environmental Gradient (cline): A change in abiotic factors (like temperature or elevation).
- Common Garden Experiment: A method to determine if a difference in trait is due to genetics or environment. It establishes if traits are the same even in different environments.
Plants Growing Near a Smelting Operation in Pennsylvania
- Methods:
- Collected samples at various distances from the smelter.
- Recorded pollution levels at the places where samples were collected.
- Counted stomata and hairs on plants.
- Grew seeds under standard conditions nearby.
Zinc Contamination in Soils
- Figure 16.6 reports zinc concentration in soils near, medium, and far from a smelting operation.
- Key finding: Higher concentration of zinc in the soils closer to the smelter.
- Data related to zinc contamination was collected and represented via a graph which detailed zinc contamination levels near, medium, and far from a smelting operation.
Copper Contamination in Soils
- Figure 16.6 reports copper concentration, also related to distance from smelters.
- Key finding: Copper levels tended to be higher near the smelter.
Stomata and Hair Densities
- Figure 16.7 shows stomata and hair densities of honeysuckle and sandwort plants at different distances from the smelter.
- Key Finding: Stomata and hair density showed significant variation in correlation with proximity to the smelter.
Barnacles
- Key Finding: Predation by snails lead to development changes in the barnacle species studied, with the shell shape of the barnacles changed in response to the snail presence.
Intertidal Habitat
- This describes the habitat where many different marine life species may coexist, including barnacles.
Experimental Set-up
- Exclusion Experiments: Methods used to determine how a certain species will interact with other organisms in the environment.
- Survival Experiments: Studying the capacity of a given species in an environment to survive against the influence of other species in their context.
Responses of Acorn Barnacle to Snail Predation
- Key Finding: Snail presence appears to impact barnacle survival and development, leading to changes in their features (shapes). Either the barnacle doesn't receive the predator detection cue, or the species may not have the genetic propensity to develop in the bent form.
Take Home
- Environmental factors can affect physical appearance, but only within the scope of an organism's genetic potential.
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Description
Explore the key concepts of variation and population genetics in Biology Chapter 16. This quiz covers individual variation, the links between genotype and phenotype, and the influence of environmental factors on genetic traits. Test your understanding of how these concepts apply to natural selection and population dynamics.
