In biology gcse level i am dumb : )

Which of these is not a function of some membrane proteins ? a.allowing polar molecules to enter the cell b.recognizing other types of cells c.receiving messeges from other cells b.carrying messages to oher cells

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a