How difficult is it for a sperm to reach the egg?

In the diagram below, the northern hemisphere would be in what season at position a a.fall b. winter c.summer d.spring

Which best describes the nucleus of an atom a. it is where all of the particle s of the atom are located b. it is the negatively charged part of the atom c. it is where the electrons and the protons are located d. it is the part of the atom with the greatest mass

Describe the two types of vascular tissue