To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
Melting of ice and island decreasing in level
The awnser is b there is a mutation in the gene
it gives off protons because it's in a basic solution (pH>7)
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.
