Why is research commonly repeated in science?

Which of the following describes this plant?

1. There are no examples of scientific research prior to the Scientific Revolution in Europe in the 16th century.

The envelope of enveloped viruses is derived from the plasma membrane of the original host cell.

What generation of a fern’s life cycle is this?     

There is more than one correct way to show relationships using a phylogenetic tree. Three of the four trees displayed below show the exact same relationship between species A, B, and C. Which tree shows a different relationship?

Label the evolutionary tree below by placing (drag and drop) the number for each characteristic at the appropriate place on the tree. (This question is worth 4 points.)1. Double fertilization                           5. Sporophyte dominant life-cycle2. True leaves (euphylls)                        6. Annulus3. Gametophyte dominant life-cycle     7. Cones4. Seeds                                                 8. Gemmae

Which of the following describes the structure pictured below?

Which of the following are true about developmental regulatory genes?

What are the extensions of cytoplasm in this protist called?