Question

ose l17 name: _____________________________ date: ________ period: __
c. consider the histogram that shows tree height data from the two areas plus the combined, total area of the redwood forest. develop a model in the space below to explain how both genetic and environmental factors in differing amounts could cause the range of height variation among all the redwoods in these areas.

Explanation:

To explain the height variation in redwoods, we consider genetic and environmental factors. Genetically, different redwood populations may have alleles (e.g., for growth - regulating genes) that influence maximum potential height. Some genotypes might be inherently more likely to grow taller, like if a redwood has a gene variant that promotes efficient cell elongation in the trunk. Environmentally, factors such as soil quality (e.g., nutrient - rich vs. nutrient - poor soil), water availability (more water supports better growth), and sunlight exposure (more sunlight for photosynthesis to produce energy for growth) vary between areas. In one area with rich soil and ample water, even redwoods with average genetic potential for height might grow tall. In another area with poor soil, only redwoods with very favorable genetics for growth might reach a decent height. The combined data (from two areas and total) shows a range because of the interaction: some redwoods have good genes and good environment (tallest), some have good genes but bad environment (moderate), some have bad genes but good environment (moderate), and some have bad genes and bad environment (shortest). We can model this as a flowchart or a concept map: start with "Genetic Factors (alleles for growth)" and "Environmental Factors (soil, water, sunlight)" as two input branches, then show how they interact to produce "Height Variation" (with different levels like short, moderate, tall) and relate it to the histogram's data distribution (e.g., more redwoods in a height range where gene - environment interaction is favorable).

Answer:

A model to explain redwood height variation:

1. Genetic Factors: Different redwood genotypes have alleles affecting growth (e.g., genes for cell elongation, nutrient uptake efficiency). Some genotypes have a higher “potential height range” (e.g., Genotype A: 50–100 m; Genotype B: 30–80 m).
2. Environmental Factors: Areas differ in soil quality (nutrient availability), water supply, and sunlight. A “favorable environment” (rich soil, ample water, full sun) maximizes a genotype’s growth; a “harsh environment” (poor soil, drought, shade) limits it.
3. Interaction & Variation:

• In Area 1 (favorable environment): Even Genotype B (lower genetic potential) can grow to 70 m (near its upper genetic limit). Genotype A can reach 100 m (its genetic upper limit).
• In Area 2 (harsh environment): Genotype B only grows to 30 m (its genetic lower limit). Genotype A grows to 80 m (below its genetic upper limit, due to environment).
• Combined data (total area) shows a range: from the shortest (Genotype B + harsh environment) to the tallest (Genotype A + favorable environment), with intermediate heights from other gene - environment combinations.

Visually, this can be represented as a concept map:
Genetic Potential (Genotype A/B/...) ↔ Environmental Quality (Favorable/Harsh) → Height (Short/Moderate/Tall) (aligned with histogram’s height - frequency distribution).