Reproductive Strategies

looking for patterns in reproduction

Benny compares the parental care of a grizzly bear with an amoeba. Stella looks at the number of parents that contribute genetic information to the offspring of leafy sea dragons and that of salmonella. Peter contrasts the genetic variation of a baby spider plant and a blue headed wrasse.

The seventh graders are taking a close look at the reproductive strategies of various organisms—some of which they are familiar with, others they are considering for the first time. It’s part of the Reproductive Strategies Life Science unit taught by Gregg Kastanis. “As soon as I say we’re doing a unit on reproduction their hands go up,” said Kastanis. “They want to focus on human reproduction. We look for patterns in sexual or asexual reproduction across many different species.”

considering the ways living things mate and raise offspring

Students record their observations on data sheets

Learnings are shared by a gallery walk in the hallway

comparing the advantages of asexual and sexual reproduction

When the class regroups, Kastanis asks: “Which is a better way to reproduce?”

“Asexual reproduction is much safer,” said Jackson. “In sexual reproduction, the parent could die. Asexual reproduction is also not as complex. It takes less time.”

Lucy agrees. “It’s easier. Only one parent is needed.”

“But genetic problems get passed down,” said Susanna. “All offspring are genetically the same.”

“Sexual reproduction takes more time and energy, and it’s not as convenient,” said Caleb, “but it’s a good thing for a species.” Kastanis clarifies his idea; sexual reproduction is good because it adds genetic diversity to species.

“The climate is changing,” said Kastanis. “Living things are under a lot of stress to survive. Species that pass on good genetic traits may be more likely to survive.”