Answer:
Constant variables
Explanation:
Elaina's investigation lacked the critical ingredient of constant variables which are important components of every scientific investigation. In every research, there are 3 important variables, namely:
1. Dependent variables: the actual variable to be measured during the course of investigations and whose values are dependent on another variable (independent variable) supplied by the investigators.
2. Independent variable: one of the variables that are supplied by investigators whose values are often manipulated to see the kind of changes it will cause to the dependent variable.
3. Constant variables: other variables that are neither independent nor dependent but constant for all the various experimental groups in investigations.
Earths lithospere is solid and sits on top of the softer asthenosphere.
Primary growth or lengthening of plants results from mitotic division in cells of the apical meristem tissue. The apical meristem can be found in the top of plants. When the plant divides, it helps to lengthen it. The correct choice is C.
Answer - sea oats
Sea oats play a vital role in the development of sand dunes. The structure of their leaves and roots help in the trapping of the wind blown sand, promoting the growth of sand dunes and their stabilization. Sea oat plantation is encouraged in coastal areas to protect damage from heavy winds and high tide.