Cell structure

Question 1

Why would a secretory cell require lots of mitochondria (2)

Answer 1

• secretory cells involved in active processes/ metabolically active
• require ATP
• hormone synthesis require ATP

Question 2

Describe the function of the rough endoplasmic reticulum (2)

Answer 2

• site of protein synthesis
• polypeptide chains build up at ribosomes
• transports polypeptides/ proteins
• ribossomes read genetic code

Question 3

Describe the function of the golgi body (2)

Answer 3

• buds off vesicles packing proteins into vesicles
• these contain molecules for secretion
• transport protein molecules to cell surface / membrane
• synthesis of glycoproteins / modification of proteins

Question 4

In a cell why does two organelles which are the same differ in appearance (1)

Answer 4

cut in a different plane

Question 5

Name a device containing an enzyme that can be used to detect a specific compount in a fluid (1)

Answer 5

biosensor

Question 6

Name an aggregation of similar cells carrying out the same function (1)

Answer 6

tissue

Question 7

Give on structural difference between prokaryotic and eukaryotic cells (1)

Answer 7

• prokaryotic has no nucleus vs eukaryotic cells have a nucleus
• eukaryotic membrane bound organelles vs prolaryotic no membrane bound organelles
• prokaryotics smaller riboomes 70s vs eukaryotic larges ribosomes 80s
• DNA circular vs DNA in chromosomes or strands

Question 8

Give one structural difference between chloroplasts and mitochondria (1)

Answer 8

• chloroplasts contain chlorophyll vs mitochondria have no chlorophyll
• grana vs no grana
• stroma vs matrix
• cristae vs no cristae
• thylakoid vs no thylakoids
• cristae vs grana
• infolding of membrane in mitocondira not in chloroplasts

Question 9

Sime cells produce and secrete digestive enzymes. Describe the part played by each of the organelles involved in the production and secretion of enzymes (10)

Answer 9

• nucleus
• contains DNA code for amino acid sequence
• carries out transcription / make RNA copy
• nucleoulus
• makes riboomes/ organises transcritption/ make rRNA
• rough ER translate mRNA put amino acids together / protein synthesis
• endoplasmic reticulum
• transport protein
• to golgi body
• packages protein into vesicle
• modifies protein or description
• secretory vesicle
• vesicle migrates towards plasma membrane
• vesicle fuses with plasma membrane
• contents of vesicles empties by exocytosiss

Question 10

Descrivbe the function og a nuclear pore (1)

Answer 10

• allows mRNa to pass out of the nucleus

Question 11

Describe the functon of the nucleolus (1)

Answer 11

• synthesis of ribosome

Question 12

Describe the function of the nuclear envelope

Answer 12

• seperates DNA from the rest of the cellular contents
• holds DNA

Question 13

Describe the role of chromatin (1)

Answer 13

• condenses to form chromosomes code for protein synthesis

Question 14

Describe the difference of smooth and rough endoplasmic reticulum when viewing through a mircoscope

Answer 14

• Prescence of ribosomes and no ribomes
• In parallel lines vs other one is less organised

Question 15

Describe the function of the golgi body (1)

Answer 15

• modification of proteins
• storage of digestive enzymes
• synthesis of secretory vesicles / packing proteins

Question 16

What tissues would contain a lot of mitochondria (1)

Answer 16

• liver
• muscle
• nervous tissue
• meristem

Question 17

What is a smaller organelle, numerous in cells , surrounded by an outer membrane has an inner membrane folded to form cristae (1)

Answer 17

mitochondria

Question 18

Describe the function of mitochondria (2)

Answer 18

• aerobic respireation
• release energy

Question 19

Describe the proces when a cell takes in a food particle (2)

Answer 19

• phagocytoses / endocytosi
• cell membrane engulfs to form a vesicle around the food particle

Question 20

Name the process when cell ejects something out it

Answer 20

exocytosis

Question 21

Suggest why mitochondria are needed while amoebas are feeding (1)

Answer 21

• carry out phagocytosis
• synthesis of digestice enzymes
• form lysosomes

Question 22

Describe three ways in which the strucuture of a prokaryotic cell would differ from an amoeba (3)

Answer 22

• no nucleus / nuclear membrane / DNA is free in cytoplasm
• no membran bound organelles/ posess mesosome
• a loop of DNA / circular DNA
• Smaller / 70s ribosomes
• cell wall
• capsule / flagelllum / plasmid

Question 23

Describe the role of the nucleus (1)

Answer 23

• contains DNa Which codes for protein synthesis

Question 24

Where a cubodial epithelial cells found (1)

Answer 24

kidney tubule

Question 25

Where are ciliated epithelial cells found (1)

Answer 25

trachea / oviduct/ fallopian tube / bronchio / bronchioles

Question 26

Describe the structure and function of the rough endoplasmic reticulum , golgi body and lysomes (10)

Answer 26

Rough endoplasmic reticulum * flattened saces / cristernae * continours with nuclear membrane * with atttatched ribsomes * ite of protein synthesis / translation Golgi body * golgi consists of a stack of flattened sacs * function in packaging proteins for secretion * vesicles containing prodteins from RER fuse with golgi membrane and contents are shed ito golgi saces * contents are built into more complex molecules such as enzymes * other golgi functions is carbohydrate secretion / transporting or storing lipids * vesicle are budded off * exocytosis of contents Lysosomes * contain digestive enzymes * function is to break down worn out orangelles / diget foreign material / intracellular breakdown * lyosomes fuse with membrane of diesitve vacuoles * enclosed by phagocytosis

Question 27

Outline how a vesicle is formed and is used in the secretion of a glycoprotein within an animal cell (3)

Answer 27

* golgi body * vesicle buds off and moves towards cell membrane * vesicle membrane fuses with cell membrane

Question 28

Describe the features of the vacoules ofund in plants cells and give one function of the vacuole (3)

Answer 28

* permanent / large * surrounded by tonoplast * storage site / turgor pressure

Question 29

Describe how the appearance of a turgid plant cell viewed under a microscope would change if it was places into a concentrated salt solution (4)

Answer 29

* vacuole volume decreases * less cytoplasm * cell membrane puller away from cell wall / plasmo;ysed * cell wall stays the same shape

Question 30

Describe the roles of the vesicle in the passage of the pollen tubes through the style of a flower (4)

Answer 30

* secretory vesicle releases digestive enzymes vesicle releases enzyme via exocytosis * the enzyme digest a path through tissues of the style * mitochondria provide ATP * Rough ER synthesize the enzymes * golgi bodies - formation of vesicle processing and modifying packaging

Question 31

Describe the digestion of the yeast cell including role of the golgi body (2)

Answer 31

* golgi body processes enzymes packages into lysosomes * lysosomes fuse with phagocytic vesicle and releases enzmyes

Question 32

Describe the structure of a virus and why it is not considered to be a cell (2)

Answer 32

* molecule of nucleic acid surrounded by a protein coat * acellular does not have membranes no cell membranes

Question 33

Explain why the volume of water released from a cell increases as the water potential of external solution increases (4)

Answer 33

* water moves into cell * by osmosis * down a water potential gradient lowering water potential outide * as water potential of the external solution increases the water potential of gradient becomes steeper * rate of osmosis increases * conctractile vacoules empty to get rid of excess water from the cell