Question

Jens Clausen and colleagues, at the Carnegie Institution of Washington, studied how the size of yarrow plants (Achillea lanulosa) growing on the slopes of the Sierra Nevada varied with elevation. They found that plants from low elevations were generally taller than plants from high elevations, as shown in the diagram. Clausen and colleagues proposed two hypotheses to explain this variation within a species: (1) There are genetic differences between populations of plants found at different elevations. (2) The species has developmental flexibility and can assume tall or short growth forms, depending on local abiotic factors. If you had seeds from yarrow plants found at low and high elevations, how would you test these hypotheses?

Short answer

1. Genetic variation is observed in plants of different heights by seed sowing.
2. The comparison of the difference in plant height at two different elevations is made to determine the developmental flexibility.

Step-by-step solution

Seed

The term ‘seed’ refers to a fertilized and matured ovule of a flowering plant that raises into a young plant, such as seedling by a complex physiological process like germination.Various uses of seeds are consumption, used as food, and manufacturing products such as starch, flour, and alcohol.

The different advantages related to seed are protection by the seed coat, nourishment through gametophyte tissue, embryo protection, and parental care to the developing embryo.

Explanation for part (1)

The yarrow plant is a flowering plant with feathery leaves that grows best in well-drained soil and is used in herbal medicine.

The sowing of seeds (planting of seeds) is done at two different elevations, such as lower and higher, to observe the genetic variation among plant populations.

Explanation for part (2)

The hypothesis involves the control group, such as low and high elevation of plant strains.

The comparison is made between the high-elevation plants growing next to the plants at lower elevations. This comparison will determine if the difference in plant height is due to conditions such as developmental flexibility.