Answer and Explanation:
12. The water has a lower osmotic pressure than the cell sap of the root hairs. Due to the osmotic difference water is drawn by osmosis across the cell wall and cell membrane into root hairs. Water moves by osmosis into adjacent cortex cells and their osmotic pressure is lowered drawing water by osmosis. Water passes to the successive cortex cells and through the endodermis to the xylem vessels. At the leaves, the xylem passes into the petiole and then into the veins of the leaf. Water leaves the veins and enters the cells of the spongy and palisade layers.
13. Food and other manufactured material are translocated by the phloem. They enter the sieve elements through plasmodesmata connecting them to adjacent companion cells which are sites of high metabolic activity. The manufactured food are translocated through sieve tube along the cytoplasmic strands.
Answer:
E. It takes a picture of the brain according to oxygen levels. More oxygen in an area indicates more activity in that area.
Explanation:
Haemoglobin is diamagnetic when oxygenated but paramagnetic when deoxygenated. This distinction in magnetic characteristics leads to tiny variations in the blood MR signal. Since blood oxygenation differs, these variations can be used to identify brain activity depending on the concentrations of neural activity.
