Key terms

Question 1

Cell

Answer 1

The basic unit of living material

Question 2

Tissue

Answer 2

A group of cells - joined together to carry out a particular task

Question 3

Organ

Answer 3

A collection of tissues joined together to carry out a specific function

Question 4

Electron microscope

Answer 4

A microscope used to see inside cells

Question 5

Photomicrograph

Answer 5

A photograph of a microscopic object, taken with the aid of a microscope

Question 6

Organelle

Answer 6

A tiny body inside a cell which carries out its own function

Question 7

Protoplasm

Answer 7

Meaning ‘first material’ - the colourless material comprising the living part of a cell, including the cytoplasm, nucleus, and all other organelles

Question 8

Cytoplasm

Answer 8

‘cell material’ - refers to anything (the protoplasm of the cell)inside the plasma membrane and outside of the nucleus/excluding circular DNA in Prokaryotic cells

Question 9

Nucleus

Answer 9

The central part of the cell, it is enclosed in a membrane and is usually darker than the rest of the cell as contains the genetic material

Question 10

Metabolism

Answer 10

The sum of all the chemical reactions involved in maintaining the living state of an organism and all its cells

Question 11

Chromatin network

Answer 11

The dark tangles mass seen in the nucleus of a resting cell

Question 12

Ribonucleic acid (RNA)

Answer 12

Nucleic acid found in both the cell and the nucleus, responsible for the manufacture of cell proteins (e.g. pigments, enzymes and hormones)

Question 13

Chromosomes

Answer 13

Long threads of DNA and protein seen in a dividing cell, which contains the genetic material, or genes, responsible for transmitting inherited characteristics

Question 14

Deoxyribonucleic acid (DNA)

Answer 14

Nucleic acid found only in the chromatin network and the chromosomes of the nucleus, which is responsible for the control the cell, and passing on inherited characteristics

Question 15

Centrioles

Answer 15

Organelles that play an important part in spindle formation during cell division

Question 16

Mitochondria

Answer 16

Spherical or rod-shaped bodies scattered in the cytoplasm, concerned with energy release

Question 17

Cristae

Answer 17

Folds of the inner layer of mitochondrial membrane, on which the enzymes responsible for the oxidation of glucose are situated

Question 18

Adenosine triphosphate (ATP)

Answer 18

A chemical in mitochondria capable of trapping and storing energy, to supply to the cell when needed

Question 19

Adenosine diphosphate (ADP)

Answer 19

A chemical left after ATP has released its stored energy to do work

Question 20

Diffusion

Answer 20

The movement of a substance from an area of high conc to an area of low conc

Question 21

Osmosis

Answer 21

The passage of water molecules from an area of high conc (of water mols) to an area of low conc, through a partially permeable membrane

Question 22

Arterial blood

Answer 22

Flows Away from the heart and is usually bright red oxygenated blood

Question 23

Venous blood

Answer 23

Flows towards the heart and is usually dark red deoxygenated blood

Question 24

Collagen

Answer 24

Structural protein in the form of fibres for extra strength

Question 25

Central nervous system

Answer 25

The brain and spinal cord

Question 26

Autonomic nervous system

Answer 26

Part of the NS responsible for controlling the internal organs

Question 27

Antagonistic muscles

Answer 27

Muscles that work in pairs. When one muscle or sheet of muscles contract while the other relaxes

Question 28

Homeostasis

Answer 28

The process of maintaining a constant internal environment despite changing circumstances

Question 29

Myelin

Answer 29

An insulating sheath around many nerve fibres, formed of proteins and phospholipids, which increases the speed of nerve conduction

Question 30

Catabolism

Answer 30

The breaking down of molecules into smaller units, releasing energy

Question 31

Anabolism

Answer 31

The building up of complex molecules using the energy released in catabolism

Question 32

Gene

Answer 32

Unit of heredity on a pair of chromosomes

Question 33

Allele

Answer 33

Half a gene or the location of a characteristic on one chromosome

Question 34

Homozygous

Answer 34

Having two dominant or recessive alleles

Question 35

Heterozygous

Answer 35

Having one dominant and one recessive allele

Question 36

Dominant

Answer 36

The allele that, when present, displays in the individual

Question 37

Recessive

Answer 37

An allele that does not show when a dominant allele is present

Question 38

Punnett square

Answer 38

A diagram used to determine the probability of an offspring having a particular genotype

Question 39

Phenotype

Answer 39

The outward display of a characteristic that is observable

Question 40

Genotype

Answer 40

An individual's genes, which are not outwardly observable, or the identification of alleles an individual inherits for a gene

Question 41

Gamete

Answer 41

Reproductive/sex cells - each cell is haploid and carries only one copy of each chromosome

Question 42

Zygote

Answer 42

Cell produced when a sperm fertilises and ovum, it contains all the genetic material for a new individual - half from the sperm and half from the ovum