Cell Biology

Question 1

What does the Cell Theory state ?

Answer 1

1) Living things are made of cells.
2) Cells are the smallest unit of life.
3) Cells come from pre-existing cells by division.

Question 2

Define nutrition.

Answer 2

Feeding by either the synthesis of organic molecules or the absorption of organic matter.

Question 3

Define metabolism.

Answer 3

The web of all the enzyme-catalysed reactions in a cell or organism.

Question 4

Define growth.

Answer 4

Living things can grow or change size or shape.

Question 5

Define response.

Answer 5

Living things can respond to and interact with the environment.

Question 6

Define homeostasis.

Answer 6

The maintenance and regulation of internal cell conditions.

Question 7

Define reproduction.

Answer 7

Living things produce offspring, either sexually or asexually.

Question 8

Define excretion.

Answer 8

The removal of metabolic waste.

Question 9

Define differentiation.

Answer 9

The development of cells in different ways to perform different functions.

Question 10

Define stem cells.

Answer 10

Cells that are unspecialised and retain the ability to differentiate along different pathways throughout their lives.

Question 11

Define induced pluripotency.

Answer 11

When some types of cells are reprogrammed to become pluripotent.

Question 12

Define prokaryotic cells.

Answer 12

Cells that do not have a membrane-bound nucleus or membrane-bound organelles.

Question 13

Define eukaryotic cells.

Answer 13

Cells that have a membrane-bound nucleus and membrane-bound organelles.

Question 14

Define plasma membrane.

Answer 14

The membrane that surrounds a cell and controls the entry and exit of substances/nutrients in cell.

Question 15

Define passive transport.

Answer 15

Movement of substances across cell membrane without any input of energy.

Question 16

Define diffusion.

Answer 16

The passive movement of particles from a region of high concentration to a region of low concentration.

Question 17

Define simple diffusion.

Answer 17

It involves particles passing between the phospholipids in the membrane.

Question 18

Define facilitated diffusion.

Answer 18

It is when large particles diffuse through the membrane by using specific protein channels.

Question 19

Define osmosis.

Answer 19

The passive movement of water from a region of lower solute concentration to a region of higher solute concentration through a partially permeable membrane.

Question 20

Define endocytosis.

Answer 20

A process by which cells take in substances by surrounding them with membrane.

Question 21

Define exocytosis.

Answer 21

A process by which cells secrete substances to external environments when vesicles fuse with the inner surface of the plasma membrane.

Question 22

Define active transport.

Answer 22

The movement of substances across a membrane against a concentration gradient.

Question 23

What are hypertonic, hypotonic and isotonic solutions and how does this affect water movement if the solutions are outside of the cells?

Answer 23

Hypertonic = high [solute], water leaves cell.
Hypotonic = low [solute], water enters cell.
Isotonic = same [solute], no net movement of water.

Question 24

Define vesicle.

Answer 24

A small sac of membrane that contains various substances.

Question 25

Define the endosymbiotic theory.

Answer 25

Organelles such as mitochondria and chloroplasts originated as symbioses between separate single-celled prokaryotic organisms.

Question 26

Define interphase.

Answer 26

An active period in the life of a cell where many metabolic reactions occur.

Question 27

Define mitosis.

Answer 27

The division of an eukaryotic nucleus to form 2 genetically identical nuclei.

Question 28

Define cytokinesis.

Answer 28

The division of the cytoplasm to form 2 separate daughter cells.

Question 29

Define emergent properties.

Answer 29

Properties that arise from the interactions between cellular components of the organism.