if one group is given some medicine that may cure a disease and the other group is given a sugar pill, the group who got the medicine is the:
Which of the following is NOT true of cell membranes?
They are composed of four carbohydrate layers.
They contain protein molecules.
They regulate movement of some substances into and out of the cell.
They contain phospholipids.
Aerobic cellular respiration requires the use of:
_ describes how a cell makes a protein from the protein coding sequence of a gene.
A gene that can be masked by another gene is called:
Hybrid plants are produced by:
Many kinds of disease-causing bacteria are resistant to the standard antibiotics that we use to control them. This is because:
when bacteria are exposed to antibiotics, they mutate.
there is genetic variety within the species and those that already have genes for resistance are the ones that reproduce.
new species of bacteria have evolved that are resistant to antibiotics.
when the size of the population of a species of bacterium is reduced, genetic variety decreases.