What’s the difference between introns and exon

What's wrong with this ecological pyramid? (multiple choice)1. secondary consumers should be at the bottom of the pyramid2. the sun has an arrow leading to decomposers 3. primary consumers should come after the sun4. energy retained should increase from the bottom to the top5. the sun should be at the bottom of the pyramid

Match each symbol with its description.

Three applications for admission to a local university are checked, and it is determined whether each applicant is male or female. the number of sample points in this experiment is