Cell structure, Variety, Levels of Organisation

Question 1

Define the term respiration

Answer 1

The release of energy (production of ATP) from food

Question 2

Define the term growth

Answer 2

A permanent increase in size; an increase in the total number of cells in an organism

Question 3

Define the term homeostasis

Answer 3

The maintenance of a constant internal environment

Question 4

Define the term reproduction

Answer 4

Producing offspring

Question 5

Define the term sensitivity

Answer 5

An organism’s response to changes in its surroundings

Question 6

Define the term excretion

Answer 6

The removal of waste products of metabolism from an organism (e.g. carbon dioxide, water(sweat), urea)

Question 7

Give three examples of organelles

Answer 7

Mitochondria, chloroplasts, ribosomes, cytoplasm, cell membrane, cell wall, vacuole, nucleus etc.

Question 8

State the function of the cytoplasm

Answer 8

Where chemical reactions take place; jelly-like substance in which organelles are suspended

Question 9

State the function of the cell membrane

Answer 9

Controls the movement of substances into/out of the cell

Question 10

State the function of the mitochondria

Answer 10

Site of aerobic respiration (release of energy; production of ATP)

Question 11

State the function of chloroplasts

Answer 11

Contain chlorophyll, a green pigment, which absorbs light for photosynthesis (making glucose)

Question 12

State the function of the cell wall

Answer 12

Maintains the rigidity/structure of a cell

Question 13

State the function of ribosomes

Answer 13

Site of protein synthesis

Question 14

State the function of the nucleus

Answer 14

Controls the cell; contains the instructions (DNA) needed to make new proteins

Question 15

State the function of the vacuole

Answer 15

Contains cell sap and maintains/supports the shape of the cell

Question 16

Give three examples of specialised cells

Answer 16

Red blood cells, white blood cells, root hair cells, liver cells etc.

Question 17

Define the terms prokaryotic and eukaryotic, giving an example of each

Answer 17

Eukaryotes contain membrane-bound organelles (e.g. mitochondria, nucleus, chloroplasts) whereas prokaryotes do not. Eukaryotic kingdoms include animals, plants, fungi and protoctists; prokaryotes are bacteria

Question 18

State three common characteristics between animals

Answer 18

Animals have nervous coordination (only kingdom that does), cannot carry out photosynthesis, do not have cell walls, can move from one place to another, store carbohydrates as glycogen

Question 19

Give three differences between an animal cell and a bacterial cell

Answer 19

Animal cells have NO cell wall, they have a nucleus (bacteria have a single, twisted chromosome), mitochondria and larger ribosomes; bacteria have plasmids (extra loops of DNA)

Question 20

Give three differences between an virus and a bacterial cell

Answer 20

Viruses have no cell membrane, no cell wall, no cytoplasm, no flagella, no plasmids and they cannot respire, feed, move etc.; viruses rely on a host cell to replicate themselves; viruses are smaller than bacteria

Question 21

Define the term pathogen

Answer 21

An infective organism that causes disease

Question 22

Give three structural differences between a plant cell and an animal cell

Answer 22

Plant cells have chloroplasts, a cellulose cell wall and a permanent vacuole. They also store carbohydrate as starch/sucrose as opposed to glycogen (animals)

Question 23

Describe how fungi feed

Answer 23

By saprotrophic nutrition; they secrete extracellular enzymes from their thread-like hyphae and digest dead/decaying matter before reabsorbing the digested products

Question 24

Give one example of a unicellular fungus and a multicellular fungus

Answer 24

Unicellular: yeast; multicellular: Mucor

Question 25

True/False: Bacteria are always unicellular. Give two examples of bacteria

Answer 25

Lactobacillus (non-pathogenic; used to make yoghurt); Pneumococcus (pathogenic; causes pneumonia)

Question 26

Give examples of two diseases caused by a virus

Answer 26

AIDS (caused by HIV); Flu (influenza); Ebola; Zika

Question 27

Give the name of a virus that causes discoloration in plants meaning their leaves lose their green colour

Answer 27

Tobacco Mosaic Virus

Question 28

State how animals, plants, fungi and bacteria all store carbohydrates

Answer 28

Animals, fungi and bacteria all store carbohydrates as GLYCOGEN; plants store carbohydrates as starch or sucrose

Question 29

State how the composition of the cell wall is different in animals, plants, fungi and bacteria

Answer 29

Animals do NOT have a cell wall; plants (CELLULOSE); fungi (CHITIN); bacteria (MUREIN)

Question 30

Give three examples of protoctists, including one which is a pathogen

Answer 30

Amoeba (animal cell-like); Chlorella (plant cell-like); Plasmodium (pathogenic; causes malaria)

Question 31

Give the name of a bacterium used to make yoghurt

Answer 31

Lactobacillus

Question 32

Describe the differences in DNA structure/organisation between animals, plants, bacteria, fungi and viruses

Answer 32

Animals, plants, fungi and protoctists all have a NUCLEUS (they are all eukaryotes so contain membrane-bound organelles); bacteria have a single twisted DNA chromosome; viruses have either DNA or RNA

Question 33

True/False: Protoctists are always unicellular

Answer 33

TRUE

Question 34

State the correct order of levels of organisation in an organism

Answer 34

Organelle, Cell, Tissue, Organ, Organ System

Question 35

Define the term tissue

Answer 35

Many different cells working together to perform a function

Question 36

Define the term organ

Answer 36

Many different tissues working together to perform a function

Question 37

Give three examples of organ systems

Answer 37

Circulatory, excretory/urinary, digestive, nervous, endocrine, reproductive, respiratory etc

Question 38

State a source of stem cells from which specialised cells originate

Answer 38

Bone marrow