A: Cells & Classification

Question 1

Active transport

Answer 1

The process by which dissolved molecules (solutes) move across a cell membrane from a lower to higher concentration. This requires energy from respiration.

Question 2

Animal kingdom

Answer 2

Kingdom of organisms which can (usually) move around but cannot photosynthesise so must obtain food from other organisms.

Question 3

Animal cell

Answer 3

Animal cells have a nucleus but do NOT have cell walls or chloroplasts and only have small vacuoles (if any). They store food as glycogen.

Question 4

Bacteria

Answer 4

Single-celled micro-organisms with no nucleus. Most are beneficial as decomposers, a few cause disease. Singular = bacterium.

Question 5

Cell

Answer 5

Basic unit of life that can carry out all life’s processes. Unicellular organisms only have one cell. Multicellular organism have many cells.

Question 6

Cell membrane

Answer 6

Partially permeable surface layer of a cell; the cell membrane [ also called plasma membrane] controls what enters and leaves the cell.

Question 7

Cell wall

Answer 7

Permeable cellulose ‘box’ surrounding cells of plants; fungi also have walls but not of cellulose. The wall offers support to the cell and stops it from bursting.

Question 8

Cellulose

Answer 8

A carbohydrate which forms the cell wall in plant cells.

Question 9

Chloroplast

Answer 9

Organelle containing chlorophyl found in green plant cells. Chloroplast perform photosynthesis.

Question 10

Cilia/ciliated

Answer 10

Ciliated cells are covered with cilia - tiny hairs which beat continuously to move mucus (e.g. carrying dirt up the bronchi and trachea)

Question 11

Cytoplasm

Answer 11

The jelly-like substance inside a cell, but outside the nucleus. Most of the cell’s chemical reaction occurs here, in various organelles.

Question 12

Diffusion

Answer 12

The movement of particles (molecules or ions), by random heat energy from an area of higher or lower concentration.

Question 13

Element

Answer 13

A substance consisting of one kind of atom only.

Question 14

Epidermis

Answer 14

The outer protective layer of the skin.

Question 15

Fungi

Answer 15

Kingdom of non-photosynthesising organisms with cell walls made of chitin. They have nuclei in their cells, which usually form long strands called hyphae.

Question 16

Goblet cells

Answer 16

Cells in the lining of the trachea and bronchi which make mucus.

Question 17

Impermeable

Answer 17

Not allowing water to pass through

Question 18

Membrane

Answer 18

A very thin layer of tissue; be careful not to confuse with with ‘cell membrane’.

Question 19

Metabolism

Answer 19

The sum of all chemical processes taking place in our cells, and the rate at which these proceed.

Question 20

Mitochondria

Answer 20

Structures of the cytoplasm of all cells where respiration takes place. Singular is mitochondrion.

Question 21

Molecules

Answer 21

A collection of two or more atoms held together by chemical bonds. The fundamental unit of compounds.

Question 22

Multicellular

Answer 22

Having more than one cell.

Question 23

Nucleus

Answer 23

Large organelle, often near the centre of a cell, where generic information is stored. This information controls all the cell’s activities.

Question 24

Organ

Answer 24

Group of tissues doing a particular job between them, e.g. the heart.

Question 25

Organ system

Answer 25

Group of organs doing a particular job between them, e.g. the circulatory system.

Question 26

Organelle

Answer 26

Microscopic structure which does a particular job in a cell, e.g. the nucleus or chloroplast.

Question 27

Organism

Answer 27

A living being - plant, animal, fungus or bacterium. Some people include viruses.

Question 28

Osmosis

Answer 28

The movement of water molecules across a partially permeable membrane down a concentration gradient; a special type of diffusion.

Question 29

Partially permeable

Answer 29

Allowing some particles to pass through but not others; e.g. the cell membrane.

Question 30

Permeable

Answer 30

Allowing water to pass through

Question 31

Plant

Answer 31

Type of organisms with chloroplasts and cellulose cell walls. By photosynthesis, plants are the ‘producers’ of food for all other organisms.

Question 32

Protoctista/Protozoa

Answer 32

Kingdom of minute, usually single-celled, organisms with a nucleus, e.g. Amoeba (protozoa is an old term).

Question 33

Sperm

Answer 33

Swimming male sex cell, which carries genetic information to the ovum (egg).

Question 34

Tissue

Answer 34

Group of cells of the same type doing a particular job, e.g. the blood (a liquid tissue)

Question 35

Unicellular

Answer 35

Having only one cell

Question 36

Vacuoles

Answer 36

A space within the cytoplasm of plant cells that contains cell sap. Vacuoles help support the cell by outward pressure on the wall.

Question 37

Virus

Answer 37

Parasitic non-cellular organism (no cytoplasm, just DNA in a protein coat). Too small to see with a light microscope, viruses infect living cells and ‘high-jack’ their metabolism ro replicate inside the cell.