How Do Plant Adaptations Compare?

Plants have adaptations that enable them to survive in their specific environments. In this activity, you will observe the plants in your neighborhood and describe their adaptations.

Problem 

What are some methods of plant reproduction, growth and development, and adaptations to the environment?

Materials 

• camera (optional)

• containers (plastic bags and jars with lids)

• small trowel or spade

• magnifying glass

• glass slides

• microscope

• coverslips

• dropper pipette

Skills 

Observing, Measuring, Inferring

Procedure 

Part A: Preparing for the Field Trip



1. Read the guidelines in the Lab Tips box and in Planning the Trip.

2. Prepare a data table similar to the one below so you can record your observations.

3. Review Sections 22-1, 24-1, and 24-2. Gather information on each consideration below.

   • Plants need light in order to make food, and they compete to obtain sunlight. Think of possible adaptations for this competition.

   • Plants have adaptations that enable them to obtain and retain water.

   • Plants depend upon mechanisms of seed dispersal and vegetative propagation to find new, suitable places to grow.

   • Plants have adaptations that enable them to reproduce sexually, such as flower structure and ways of enabling pollen to reach flowers.

4. Write a plan for the field trip. Have your teacher review the plan.


Part B: Working at the Site



5. On the day of your trip, read and follow the guidelines in During the Trip.

6. When you locate an interesting plant, record your observations in your data table, shown below. Number that plant and record its number in the table. Then, as you supplement your observations with drawings or photographs, place that number on each image.

   
   

7. For each plant, make the following kinds of observations:

   • Where is the plant found? Is its location sunny or shady, moist or dry? Is the soil sand, clay, or humus? What plants or other organisms are on or near it?

   • Observe the amount and source of water in the environment. Is the soil moist or dry? Is there a body of water nearby?

   • What kind of leaves does the plant have? Are they broad or narrow, large or small? What color are they?

   • How does the plant compete for sunlight? Is it tall? Does it have a thick stem or trunk to support its height? Does it climb on other plants? If so, how? Does it float on the surface of the water?

   • How does it get water? Does it have a long taproot or fibrous branching roots? You may need to dig to observe this.

   • Is there evidence of vegetative propagation? Look for runners (overground stems with new plants at the end), rhizomes (underground stems that sprout new leaves along the length), bulbs that form clusters, and so on.

   • Is there evidence of sexual reproduction? Are there cones, flowers, seeds, or fruits?

   • Most seed plants absorb all their minerals from the soil and produce their food by photosynthesis. Some seed plants are parasitic, however. Others that live in nitrogen-poor soil may supplement their diets by eating insects. What evidence is there for the manner in which your plants get food?

8. Collect the following samples to bring back to the classroom, if they are available:

   • leaves, pine cones, seeds, and fruits from various plants (make sure you know which plants they came from)

   • small plants or parts of plants that you may wish to press or otherwise preserve

9. Wash your hands with soap and warm water.


Part C: Following the Field Trip



10. Examine the size and shape of the leaves you collected. In general, the larger the leaf, the more rapidly it loses water.

11. Examine the flowers you collected. Look for adaptations to prevent self-pollination. Some adaptations that are easy to see are separate male flowers (stamens only), female flowers (pistils only), and flowers in which the pistil extends significantly beyond the anthers.

12. Look for adaptations to aid pollination. Are the petals large or small, brightly colored or greenish? Are the flowers odorless or do they have strong odors? Are the pollen grains small and powdery or large and sticky? Prepare a wet mount of the pollen grains and examine them with a microscope. Always keep track of which plant specimen you are examining.

13. Examine the fruits and seeds you collected to identify adaptations that aid dispersal by either animals or wind. Are the fruits fleshy or dry? Do they smell like food? Are they brightly colored or basically green or brown? Do the dry fruits have structures that look like parachutes, feathers, or wings? Do they have spines or hooks like burrs?

14. Wash your hands with soap and warm water when you are finished.

Analyze and Conclude 

1. Comparing and Contrasting Describe the most unusual plant adaptations you observed. How do they compare with the more common plant structures you examined?

2. Observing Describe ways that the plants you observed are adapted to obtain light.

3. Analyzing Data Examine your observations to determine the relationship between availability of water and the size and shape of the leaf. Explain how this relationship contributes to the plant's survival.

4. Analyzing Data What relationship is there between a particular plant's reproductive structures, such as flowers and pollen? How do the structures contribute to the plant's reproductive success?

5. Inferring How do the structures you observed on seeds or fruits aid in the dispersal of plants?

6. Drawing Conclusions What overall patterns did you observe in the number, size, and type of plants? How are those patterns related to the environment's physical factors such as amount of sunlight, availability of water, and type of soil?

7. SAFETY How did you demonstrate safe practices during this investigation?