How does crossing over result in diversity within a species?

The body of water found at number 4 on the map above is the

Drag each description to the correct location on the image. not all descriptions will be used. describe the parts of a comet. the frozen part of the comet the atmosphere of gases and dust formed when the nucleus vaporizes tail made of small, solid dust particles tail made of ions that appears to point away from the comet's orbit

What are the pros and cons of transect sampling?