Question

Alice wants to test how warmer temperatures that occur over onenight can affect pollen germination in the Nicotianatabacum plant. She knows that the plant prefers 20–30 °C(68–86 °F). She sets up an experiment where her plants are storedin an incubator with regulated temperature: the incubator is keptat 20–30 °C (68–86 °F) during the day and increases to 35-40 °C(95-104°F) at night. She will leave the plants in the incubator for24 hours. Alice hypothesizes that plants exposed to warmertemperature for a night will have increased germination.

A) What is her positive control?

-Nicotiana tabacum plant left at 20-30 °C

-Aloe maculata plant left at 20-30 °C

-Nicotiana tabacum plant left at 35-40 °C

-Aloe maculata plant left at 35-40 °C

B) What is her independent variable?

-The temperature of the incubator

-Nicotiana tabacum plant

-Percent germination

-Elongation rate

C) What is her dependent variable?

-Percent germination

-Initiation time

-If the pollen germinates

-The temperature of the incubator

D) What is her ideal negative control?

-A temperature that prevents Nicotiana tabacum pollen growth

-A temperature that prevents Aloe maculata pollen growth

-Immature Nicotiana tabacum pollen

-Nicotiana tabacum pollen in cedar oil