Question

	1..The plasma (cell) membrane	is composed of a bilayer of proteins
		is composed of a bilayer of phospholipids
		is composed of chains of carbohydrate molecules
		is a compl;ex of carbohydrates and proteins

H..Which of the following is not a function of membrane proteins?

		act as carrier molecules for various solutes
		cell nutrient
		act as anchors or stabilizers for the cell membrane
		regulate the passage of ions
		bind to ligands

I...The control center for cellular operations is the

		mitochondria.
		Golgi apparatus.
		endoplasmic reticulum.
		nucleus.
		ribosome.

J.During the G1 phase of the cell cycle:

		growth and normal metabolism occur
		the DNA replicates
		the nuclear membrane disappears
		the centrioles separate

K..Crenation of a cell may occur when it is placed in a(n)________ solution

		neutral
		isotonic
		hypertonic
		hypotonic

Answer 1

1) B. Is composed of bilayer of phospholipid.

A cell membrane is a biological membrane which is formed By a double layer of lipids and proteins that surrounds a cell and separates the cytoplasm from its surrounding environment.

2) B. Cell nutrition.

The plasma membrane helps in providing structure and protection to the cell. It has no nutritional role. I regulates the membrane permeability and binding of different molecule it hormones.

3)D. Nucleus

Nucleus is an organelle found in almost all eukaryotic cell which contains all DNA and hereditary information. It controls and regulates the function in a cell.

4) A. Growth and normal metabolism.

The G1 phase is the time in which a cell grows. During this phase, the cell synthesizes various enzymes and nutrients that are needed later on for DNA replication and cell division.

5) C. Hypertonic

In hypertonic solution, the water from the cell leaves and moves outside, making cells flaccid. This is know as crenation. It is due to osmosis of water.