Cells

Question 1

Nucleus

Answer 1

The cells control centre, containing most of the cells DNA

Question 2

Mitochondria

Answer 2

The site of fat and sugar digestion in the cell, produces energy

Question 3

Lysosomes

Answer 3

Produce powerful enzymes that aid in digestion and excretion of substances and worn out organelles

Question 4

Ribosome

Answer 4

A small structure that functions in protein assembly

Question 5

Cell membrane

Answer 5

The cells wall that regulates the flow of substances into and out of the cell

Question 6

Smooth endoplasmic reticulum

Answer 6

A network of tubes and flat curved sacs that help to transport materials through cell, site of calcium storage, main location of fat metabolism

Question 7

Golgi

Answer 7

Organelle that processes and repackages proteins produced in rough endoplasmic reticulum for release at cell membrane

Question 8

Rough endoplasmic reticulum

Answer 8

Folded membranes extending throughout cell, studded with ribosomes, help transport materials through cell, site of much protein manufacture.

Question 9

Cytoplasm

Answer 9

Jelly-like fluid in which organelles float, primarily water but also contains enzymes and amino acids

Question 10

Microtubules

Answer 10

Part of the cells cytoskeleton, aid movement of substances through the watery cytoplasm.

Question 11

Diffusion

Answer 11

Small molecules such as glycerol, water,oxygen and carbon dioxide across the membrane by diffusion.
Many molecules naturally move from an area where they are in high concentration to one in which their numbers are fewer.

Question 12

Facilitated diffusion

Answer 12

Molecules that cannot cross into the membrane have to use facilitated diffusion.
A carrier protein binds with a specific molecule, such as glucose, outside the cell, then changes shape and ejects the molecule into the cell

Question 13

Active transport

Answer 13

Molecules bind to a receptor site on the cell membrane, triggering a protein, which changes into a channel through which molecules can pass through.

Question 14

Epithelial cells

Answer 14

These cells form skin, cover most organs and line hollow cavities. The cells shown here are from the top surface of the intestinal tract.

Question 15

Photoreceptor cells

Answer 15

A cone cell is a type of light-sensitive cell that is found in the retina of the eye. Cone cells are activated by bright light and are responsible for colour perception.

Question 16

Red blood cells

Answer 16

The red cell(erythrocyte) is a bag of oxygen-carrying haemoglobin molecules. It’s double-dished shape allows for rapid, maximum oxygen absorption

Question 17

Adipose(fat) cell

Answer 17

The main adipose cells, adipocytes, are bulky and crammed with droplets of fat(lipids) which store energy in case the diet cannot meet requirements.

Question 18

Smooth muscle cell

Answer 18

The large, elongated, spindle-like cells of smooth muscle are known as muscle fibres. The shape allows for contraction by means of sliding strands of protein inside.

Question 19

Nerve cell

Answer 19

Each cell has a configuration of short extensions to receive nerve signals, and a long wire(axon) to send signals to other cells.

Question 20

Sperm cell

Answer 20

Each sperm cell has a head that carries the paternal set of genetic material, and a long, whip-like tail which propels it towards the egg.

Question 21

Ovum(egg) cell

Answer 21

These giant cells contain the material complement of genetic material, and energy resources for the first cell division that shape the early embryo.