What does using <> in a class header mean in python

Shown below is the start of a coding region within the fist exon of a gene. 5'--3' 3'--5' how many cas9 pam sequences are present?

Given int variables k and total that have already been declared, use a while loop to compute the sum of the squares of the first 50 counting numbers, and store this value in total. thus your code should put 11 + 22 + 33 + + 4949 + 50*50 into total. use no variables other than k and total.

In which part of a professional email should you try to be brief, but highly descriptive?