plz help A disease resistance gene is a gene that either lessens the symptoms of a disease or helps an organism avoid getting the disease in the first place. Explain why the mutation to the CCR5 gene results in an allele that provides disease resistance.

How does land development destroy ecosystems? it increases human carrying capacity too rapidly. it converts them into residential or agricultural areas. it forces humans to import non-native plants and animals. it expands the natural range of native wildlife species.

Match the examples to the correct level of organization. 1. system level roses, snakes, puppies 2. organism level roots, stamens, leaves 3. tissue level bone, cartilage, blood 4. organ level heart, veins, arteries

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.