There was a positive sucrose uptake. Sucrose probably entered the cells by-?

Question

a) endocytosis
b) osmosis
c) exocytosis
d) phagocytosis
e) active transport
I think it's not osmosis or exocytosis. That leaves endocytosis, phagocytosis, and active transport. Active transport is the taking in of materials through protein channels from an area of low concentration to an area of high concentration. Endocytosis is the process of taking in substances through engulfing something or creating a tiny vacuole for it. Then phagocytosis, which is a form of endocytosis. but it's the engulfing of large material such as food i'm guessing. Please tell me what it is and why.

Answer 1

Actually your question is a bit tricky, since you don't define the exact conditions and what type of cells you are referring to...

Osmosis is definetely excluded since it refers to the movement of water.
Exocytosis is definetely excluded since it refers to secretion
Phagocytosis (as Need_Help said) refers to big things like organelles and even whole cells

So we are left with endocytosis and active transport.

Endocytosis is possible (for fluid and solutes uptake via small vesicles it is termed pinocytosis)

Active transport requires that within the cell the concentration of sucrose is higher than outside. I think this is highly unlikely in general. If it were glucose then it is possible and it actually occurs in intestinal epithelial cells.

The most probable way would be passive transport, but they don't give you this option.

From the options you have endocytosis seems more plausible, though you really need to define the cells and conditions before ruling out active transport.

Answer 2

phagocytosis generally refers to the endocytosis of large molecular objects like apoptosized cells, so it's not that. endocytosis is the absorption of large molecules that active transport can't bringe in. sucrose is just a disaccharide - glucose+fructose - i think active transport is the answer.