Answer Key: On Butterfly Wings

Lesson Plan: Science Soars On Butterfly Wings!

II. While Reading Activities

Word Inference

  1. knocked our socks off informal idiom –amaze or impress someone.
  2. melanin |ˈmelənən| noun-a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight.
  3. species |ˈspēsēzˈspēSHēz| noun (pl.same) (abbr.: sp., spp. )Biology a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g., Homo sapiens.
  4. evolve  |ēˈvälv|verbdevelop gradually, especially from a simple to a more complex form: [ no obj. ] : the company has evolved into a major chemical manufacturer | the Gothic style evolved steadily and naturally from the Romanesque | [ with obj. ] : each school must evolve its own way of working.
  5. DNA |ˌdē ˌen ˈā| noun-Biochemistry deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
  6. genes |jēn| noun Biology-(in informal use) a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring: proteins coded directly by genes.
  7. pattern |ˈpadərn| noun-a repeated decorative design: a neat blue herringbone pattern.
  8. delete |dəˈlēt| verb [ with obj. ] remove or obliterate (written or printed matter), especially by drawing a line through it or marking it with a delete sign: the passage was deleted.
  9. expand |ikˈspand| verb-become or make larger or more extensive: [ no obj. ] : their business expanded into other hotels and properties | [ with obj. ] : baby birds cannot expand and contract their lungs.
  10. pigment noun |ˈpiɡmənt|the natural coloring matter of animal or plant tissue.

Source: New Oxford American Dictionary

Reading Comprehension


The WntA gene becomes active in the caterpillar stage, impressing its patterning information on the embryonic wing structures. Dr. Martin sees the WntA gene as a sketching tool that defines the outline of the wing design, and the optix gene studied by Dr. Reed’s group as a “paintbrush” gene that fills in the color.

Grammar Focus: Prepositions

The biologists had already suspected that optix played a role in activating the butterfly’s brown pigment. But they were surprised that the black pigment was turned on in the absence of optix.  Dr. Reed hopes in time to understand the patterning mechanism so well that he will be able to recreate the pattern of one butterfly’s wings on those of a second species. But understanding butterfly wing patterning is just a step toward addressing larger questions in evolutionary biology.