M1 U1 Cells (keywords)

Question 0

Resolution

Answer 0

Is the degree to which it is possible to distinguish between two objects that are very close together. The higher the resolution, the greater the detail you can see.

Question 1

Magnification

Answer 1

The degree to which the size of an image is larger than the object itself. Numerically, it is the image size divided by the actual size of the object, measured using the same units. It is usually expressed as x10, x1.5, etc.

Question 2

A micrometre

Answer 2

Is equal to one millionth (10^-6) of a metre. It is the standard unit for measuring cell dimensions.

Question 3

A nanometre

Answer 3

Is one thousandth (10^-3) of a micrometre. It is therefore one thousand millionth (10^-9) of a metre. It is a useful unit for measuring the sizes of organelles within cells and for measuring the size of large molecules.

Question 4

Staining

Answer 4

In microscopy refers to any process that helps to reveal or distinguish different features. In light microscopy, stains may be colours or fluorescent dyes. In electron microscopy, they are metal particles or metal salts.

Question 5

The cytoskeleton

Answer 5

Refers to the network of protein fibres found within cells that gives structure and shape to the cell, and also moves organelles around insides cells.

Question 6

The term organelle

Answer 6

Refers to a particular structure of a cell that has a specialised function. Some organelles are membrane bound, others are not. All perform a particular role in the life processes of the cell.

Question 7

The phospholipid bilayer

Answer 7

Is the basic structural component of plasma membranes (cell surface membranes). It consists of two layers of phospholipid molecules. Proteins are embedded in this layer.

Question 8

Fluid mosaic

Answer 8

Refers to the model of cell membrane structure. The lipid molecules give fluidity and proteins in the membrane give it a mosaic (patchwork) appearance. The molecules can move about.

Question 9

Cell signalling

Answer 9

Cells communicate with one another by signals. Many molecules act as signals- some signal during processes taking place inside cells; others signal from one cell to others. Cytokines are an example of cell signals.

Question 10

Diffusion

Answer 10

Is the movement of molecules from a region of high concentration of that molecule to a region of lower concentration of that molecule down a concentration gradient.

Question 11

Active transport

Answer 11

Refers to the movement of molecules or ions across membranes, which uses ATP to drive protein ‘pumps’ within the membrane.

Question 12

Solute

Answer 12

A solid that dissolves in a liquid.

Question 13

Solvent

Answer 13

A liquid that dissolves solids.

Question 14

Solution

Answer 14

A liquid containing dissolved solids.

Question 15

The cell cycle

Answer 15

Describes the events that take place as one parent cell divides to produce two new daughter cells which then grow to full size.
In some organisms, the cell cycle is the life cycle, and each daughter is a new single celled organism.

Question 16

Mitosis

Answer 16

Refers ti the process of nuclear division where two genetically identical nuclei are formed from one parent cell nucleus.

Question 17

Clones:

Answer 17

Genetically identical cells or organisms derived from one parent.

Question 18

Differentiation

Answer 18

Refers to the changes occurring in cells of a multicellular organism so that each different type of cell becomes specialised to perform a specific function.

Question 19

Tissue

Answer 19

A collection of similar cells that carry out a specific function

Question 20

Organ

Answer 20

A collection of tissues that work together to carry out a specific function