Why do scientists use controlled experiments

Which statement correctly describes other ways in which nebulae and stars are different? A. A star always has a higher density than a nebula. B. Stars can form inside a nebula but a nebula can never be produced by any star. C.

Where are promoters usually located? A. Upstream of the start site B. Downstream of the start site C. Near nucleotide + 25 D. Near the hairpin loop E. Downstream of the terminator

Which part of the body does the pelvis protect? A. spinal cord B. lungs and heart C. reproductive organs D. brain

What is IBD (more specifically, Chrohn's Disease) ?

Primate females: a. give birth to more offspring than do many other mammals b. give birth to twins regularly c. invest less in their offspring than do many other mammals d. give birth to fewer offspring than do many other mammals

The greenhouse effect is related to the increase in average surface temperatures known as

Which of the following is true about spring tides but is not true about neap tides? they must occur during a new moon in spring they occur during the moon's first quarter and third quarter phases they only occur during a full moon they can occur

Animal cells are bathed in an isotonic fluid, and plant and bacteria cells have a cell wall. What does this protect the cell membrane from?

Explain why latin is the basic for many scientific names

What is incomplete penetrance and what causes it? incomplete penetrance means the heterozygote has an intermediate phenotype between the two homozygous phenotypes because of interactions with environmental factors.