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.
Answer:
Influenza (The Flu)
Explanation:
Influenza (the flu virus) is a real-life example of natural selection that is most evident during an annual time period when the influenza virus infection peaks. The repeated or cyclical nature of flu outbreaks is caused by the natural selection of the virus for traits that allow it to evade the immune system and replicate, a process that actually results in new distinct strains of influenza virus.
Answer: Species stay the same for a long time and then
change quickly due to environmental changes.
A punctuated equilibrium theory
states that
individual species tend to stay the same or no change over a long period of
time and then enter a period of rapid change due to environmental changes,
which gives rise to new species. Moreover, it generally applies to sexually
reproducing organisms but other biologists have applied the model to non-sexual
species like virus.
Answer:
the sun
Explanation:
All the energy in oil, gas, and coal originally came from the sun, captured through photosynthesis. In the same way that we burn wood to release energy that trees capture from the sun, we burn fossil fuels to release the energy that ancient plants captured from the sun.
hope this helps
Answer:
money
Explanation:
Potable water is the water, which is tested and safe for drinking purposeS and cooking preparations. The water is tested and purified in industries. So, potable water is costly.