1. Testing only one variable
A controlled variable means its the one that stays the same. In a controlled experiment, it means there is only one manipulated, (changed) variable.
The dorsal side<span> of the </span>leopard frog<span>: a. Is a light, solid colour b. Is a coloured and patterned. Is initially cut during a dissection</span>
The statement environmental influences begin at birth and continue throughout life is definitely False.
<h3>What do you mean by Environment?</h3>
Anything which is present in the surrounding of an organism is called its environment. The environment is surrounded by abiotic and biotic factors.
Environmental influences will not remain the same throughout life. If a human is affected by a natural disease, it will definitely be cured with medications. Environmental influences sometimes behave as genetic diseases, which stay long or sometimes endless.
Therefore, the statement environmental influences begin at birth and continue throughout life is definitely False.
To learn more about Environmental influences, refer to the link;
brainly.com/question/503225
<span>By filtering the air so that the lungs so the lungs don't get infected</span>