quiz 18 Flashcards
What is the equation for calculating image size?
actual size x magnification= image size
What is the defintion of osmosis?
the movement of water molecules from a low to high concentration through partially permeable membrane
Why do nerve cells have lots of mitochondria?
To release the energy needed to send messages
What is the function of a sperm cell?
to swim to the egg and fertilise it
What is the function of the permanent vacoule?
it contains cell sap(to keep the cell rigid)
What is the function of mitochondria?
Where respiration takes place
What do we call a solution that is more concentrated than in a cell?
Hypertonic
What is the function of a root hair cell?
to take in water and minerals
When do most cells differentiate?
At an early stage of development, starting after the 8-cell stage of an embryo
What are the 3 organelles that may be present only in plant cells?
cell wall,vacoule and chloroplasts
Give an example of stem cells in plants
in the meristems, found in the shoot tips and root tips
Give 3 adaptations of muscle cells
fibres,store glycogen and lots of mitochondria
Give an example of a plant cell that uses active transport
root hair cell
In order to enter a cell, which part of the cell must particles cross?
the cell membrane
What is DNA?
the way cells store genetic information
