Answer:
Because each subject in an experiment has to have equal conditions to ensure the most accurate results. And water temperature is known to impact plant growth. An experiment using different water temperatures is a terribly inaccurate experiment.
Answer:
A human heart is roughly the size of a large fist.
Explanation:
but the size varies according to an individual's age, health and size. The heart weighs 7 to 15 ounces.
Answer:
The correct answer is None of these choices are correct.
Explanation:
Crossing over doesn't occur only between heterozygous genes, it also doesn't happen only in some chromosomes and it never reduces de variation, otherwise, the crossing over is one of the main causes of variation among species.
Explanation:
In Earth’s history before the Industrial Revolution, Earth’s climate changed due to natural causes not related to human activity. Most often, global climate has changed because of variations in sunlight. Tiny wobbles in Earth’s orbit altered when and where sunlight falls on Earth’s surface. Variations in the Sun itself have alternately increased and decreased the amount of solar energy reaching Earth. Volcanic eruptions have generated particles that reflect sunlight, brightening the planet and cooling the climate. Volcanic activity has also, in the deep past, increased greenhouse gases over millions of years, contributing to episodes of global warming