By exploring a variety of seeds and seed pods and creating a seed of their own, students understand the benefits that the development of pods have for plants’ survival.
Construction paper leaves (pre-made)
Prior to the activity, the teacher obtains a variety of seeds and seed pods. The teacher also creates large leaves out of construction paper and string that will become the pods protecting the students’ seeds.
The student will:
Examine seeds and seed pods both tactually and with magnification if possible.
Split open seed pods and examine the seeds inside the pod noting how they are attached to the pod.
Examine some leaves, noting the feel of the vein structure and the shapes.
Examine the construction paper leaf noting the string forming the veins.
Using glue or tape attach beads to the edges of the leaf at the end of each vein.
students doing pea pod activity
Note what happens to the beads as the leaf is shaken and the seeds fall. Did the seeds necessarily fall where they could receive needed nutrients to grow?
Reposition the seeds on to the leaf, then carefully fold the leaf in half enclosing the beads/seeds and tape the pod shut.
Notice how the shape of the folded leaf actually is very similar to the shape of the pods already on the tray.
If tape or glue are difficult for a student to use independently, use of adhesive foam shapes are readily attached to the construction paper leaves. Also, the leaves can be made as large as possible to help students who who find it difficult to manipulate small items, such as beads.
LS4.B: Natural Selection
Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information—that is, trait variation—that leads to differences in performance among individuals. (HS-LS4-2),(HS-LS4-3)
The traits that positively affect survival are more likely to be reproduced, and thus are more common in the population. (HS-LS4-3)
Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment. (HS-LS4-2)
Natural selection leads to adaptation, that is, to a population dominated by organisms that are anatomically, behaviorally, and physiologically well suited to survive and reproduce in a specific environment. That is, the differential survival and reproduction of organisms in a population that have an advantageous heritable trait leads to an increase in the proportion of individuals in future generations that have the trait and to a decrease in the proportion of individuals that do not. (HS-LS4-3),(HS-LS4-4)
Adaptation also means that the distribution of traits in a population can change when conditions change. (HS-LS4-3)
Changes in the physical environment, whether naturally occurring or human induced, have thus contributed to the expansion of some species, the emergence of new distinct species as populations diverge under different conditions, and the decline–and sometimes the extinction–of some species. (HS-LS4-5),(HS-LS4-6)
Species become extinct because they can no longer survive and reproduce in their altered environment. If members cannot adjust to change that is too fast or drastic, the opportunity for the species’ evolution is lost. (HS-LS4-5)