Comp TIA A+ midterm review

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?

1. which of the following is a search engine? a) mozilla firefox b)internet explorer c)google d)safari 2. which of the following statements is true? a) all search engines will provide the same results when you enter the same query. b) all search engines use the same amount of advertisements. c) some search engines are also browsers. d) search engines often provide different results, even when you enter the same query.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?