Question

1. many kinds of bacteria are killed by antibiotics. some bacteria, however, develop a mutation that allows them to survive even when treated with antibiotic drugs. a group of scientists grows two groups of bacteria. in one group, they insert the mutant gene that prevents bacteria from being killed by antibiotics, which they call

\ for resistant. the other group of bacteria, called \c\ for control, they leave alone. they set up four petri dishes. the contents of each dish and kind of bacteria are shown in the table. the scientists tape the dishes closed, and keep them in a warm, dark place for three days. the illustration shows what plate 3 looks like after three days. the color shows that bacteria grew in the petri dish. predict what the other plates will look like by completing the model. - draw what the other plates will look like by completing the model. - draw and label what should happen on each plate. - write a caption for each petri dish, explaining why the bacteria will or will not grow. petri dish | contents of petri dish | bacteria type 1 | food only | bacteria r 2 | food and antibiotic | bacteria r 3 | food only | bacteria c 4 | food and antibiotic | bacteria c petri dish 1 petri dish 2 petri dish 3 petri dish 4

Explanation:

1. Petri Dish 1: Bacteria R has the resistant gene and access to food (no antibiotic to hinder growth), so it will grow fully.
2. Petri Dish 2: Bacteria R has the mutation that makes it antibiotic-resistant, so it can grow even with the antibiotic present alongside food.
3. Petri Dish 3: Bacteria C (non-resistant) has food and no antibiotic, so it grows fully (as shown in the illustration).
4. Petri Dish 4: Bacteria C has no resistance to antibiotics, so the antibiotic will kill them, preventing growth.

Answer:

• Petri Dish 1: (Draw a fully colored circle, labeled "Bacteria R growth")

Caption: Bacteria R grows; no antibiotic, has food.

• Petri Dish 2: (Draw a fully colored circle, labeled "Bacteria R growth")

Caption: Bacteria R grows; it is antibiotic-resistant.

• Petri Dish 3: (Fully colored circle as shown, labeled "Bacteria C growth")

Caption: Bacteria C grows; no antibiotic, has food.

• Petri Dish 4: (Draw an empty circle, labeled "No bacteria growth")

Caption: Bacteria C dies; it is not antibiotic-resistant.