c6 cell organism test Flashcards

Question

What is the name of the model of cell membrane?

Answer 1

fluid mosaic model.

Answer 2

1. Nucleus: contains DNA, double membrane 2. Cytoskeleton: acts as skeleton and muscle (provides shape and structure), helps move organelles around the cells made of 3 types of filaments: microtubules, actin filaments, intermediate filaments) 3. Endoplasmic reticulum (rough and smooth) - highway of the cell, connected to nuclear membrane Rough: studded with ribosomes- makes proteins Smooth: no ribosomes- makes lipids 4. Ribosome: site of protein synthesis, found attached to rough ER or floating free in cytosol, produced in nucleolus 5. Glogi apparatus: looks like a stack of plates, stores/modifies/packages proteins (post office), transports molecules through vesicles (lil balls) 6. Lysosome: garbage disposal of the cell- breaks down wastes with digestive enzymes 7. Mitochondria: performs cellular respiration to release energy for the cell to use, double membrane, has its own strain of DNA 8. Centrioles: aid in cell division, made of microtubules 9. Cytoplasm: holds components of the cell at their places and protects them from damage, provides structure for the cell 10. Nucleolus: sphere, produces and assembles the cell’s ribosomes 11. Vesicles: A small sac formed by a membrane and filled with liquid. Vesicles inside cells move substances into or out of the cell.

Answer 3

Rough ER -> Golgi apparatus -> Lysosome

Answer 4

1. Chloroplasts: found only in plant cells, protists and monera; contains chlorophyll; site of food production (glucose); double membrane 2. Cell wall: found in plant and bacterial cells, rigid protective barrier, located outside of cell membrane, made of cellulose (indigestible) fibre 3. Large central vacuole: storage compartment for food, water, waste, enzymes (e.g. lysosome), pigments, etc.

Answer 5

Active transfer.

Answer 6

Microbes in their stomach are able to break down cell wall.

Answer 7

(google for ans)

Answer 8

ans on google

Answer 9

1. Protect cell 2. Control incoming and outgoing substances 3. Maintain ion concentrations of various substances 4. Selectively permeable- allows some molecules in, some kept out.

Answer 10

Solvent- the liquid in which the solute is poured and dissolved. (e.g. water, alcohol, petrol) Solute- substance that is dissolved or put into the solvent. (e.g. salts, sugars)

Answer 11

1. diffusion: movement of molecules from an area of high concentration to an area of low concentration 2. osmosis 3. facilitated diffusion 4. active transport

Answer 12

Nucleus, nucleolus, large central vacuole, cell membrane, chloroplast, cytoplasm, cell wal

Answer 13

Any organelles.

Answer 14

movement from one side of a membrane to another, un-facilitated.

Answer 15

Water moving from a high concentration of water (less solute) to a low concentration of water (more solute). -> water would cross a selectively permeable membrane from a dilute solution to a concentrated solution (more dissolved in it).

Answer 16

Lots of water, less solute.

Answer 17

Less water, more solute.

Answer 18

The direction most of the water is travelling in.

Answer 19

Water is always moving both ways across a membrane.

Answer 20

Plasma membrane.

Answer 21

The measurement of concentration change as particles travel across one membrane to another.

Answer 22

When the concentration gradient is 0, where the 2 sides have exactly the same amount of the same particle.

Answer 23

The passive movement of molecules across the cell membrane via the aid of a membrane protein. - Utilised by molecules that are unable to freely cross the phospholipid bilayer (e.g. large, polar molecules and ions)

Answer 24

When enzymes use energy in the form of ATP to transport molecules against a concentration gradient -> moving water towards a diffused solution.

Answer 25

Through microscopic pores in the membrane.

Answer 26

Low amount of solute, less salts than cytosol (water)>

Answer 27

High amount of solute, more salts than the cytosol. (e.g. dead sea)

Answer 28

Selectively permeable.

Answer 29

dissolution or disruption of cells.

Answer 30

Cytolysis is a cell death which occurs as the result of a rupture in the cell's membrane. When a cell experiences cytolysis, it bursts, scattering its contents in the process.

Answer 31

Plasmolysis is the process of shrinking of plasma membrane from the cell wall when the cell is placed in a hypertonic solution. This happens due to exosmosis as water moves out of cell into the solution. water leaves cell -> shrink -> membrane pulls away from cell wall -> no structure -> wilts

Answer 32

The larger the surface area:volume ratio is, the higher the diffusion rat. As that means the substance has more surface area to diffuse across, despite having a smaller volume.

Answer 33

the process of maintaining salt and water balance (osmotic balance) across membranes within the body- form of homeostasis. Done by keeping the concentration of body fluids outside the cell the same as it is inside.

Answer 34

Excess water in the body that is not used goes to the bladder and gets excreted. (contains harmful urea)

Answer 35

If the concentration of the cell sap (liquid inside large central vacuole of cell) is greater in one cell than in its neighbour, water will pass by osmosis from the less concentrated to the more concentrated.

Answer 36

- heat is given off - oxygen is used up - co2 produced - glucose used up

Answer 37

- Endocytosis: taking particles into a cell - Exocytosis : when vacuoles expel their contents to the outside (e.g. osmosis)

Answer 38

Engulfing a liquid= pinocytosis Engulfing a solid= phagocytosis

Answer 39

- The cell membrane acts as a selectively permeable membrane - the cell wall is freely permeable to water - The vacuole contains a solution of salts and sugars (*concentrated solution) - water diffuses into the vacuole if there is water outside the cell - vacuole expands, pushing cytoplasm outwards against the cell wall and makes the plant turgid. - the pressure of the vacuole against the cell wall makes the cell very firm because the cellulose cell wall cannot stretch

Answer 40

- CELL WALLS ARE EXPANDABLE AND SAID TO BE STILL PLASTIC - when the vacuole takes in water, it expands, pushing out on the cell wall, and increasing the size of the cell

Answer 41

1. number of cells 2. size

Answer 42

It expands to push the excess water out of a cell to prevent it from bursting.

Answer 43

- Blood (animal) Biconcave - Large surface area for absorbing oxygen - no nucleus so they won’t carry it mitosis/meiosis

Answer 44

- found in the muscles (animal - can stretch to allow lengthening of muscles

Answer 45

- found in the ovary (animals and plants) - contains large food storage and genetic material to grow and develop - Lots of energy for growth - 1/2 DNA

Answer 46

- Testes (animal) - Long flagellum which allows cell to swim - Lots of mitochondria to power movement - Enzymes in the head to break into egg cell - carries DNA

Answer 47

- found in the plant stem (plant) - acts like a straw and draws water up the plant, function is transpiration - hollow to carry water DEAD

Answer 48

- anther (plant) (the juicy bit that contains pollen) - small and light to be easily transferred to the egg cell in the plant - lots of energy - 1/2 DNA

Answer 49

- found in the plant root (plant) - large perturbation maximises SA:V, therefore maximises water absorbed into plant cells - no chloroplast - has lots of mitochondria

Answer 50

- found in the leaf of plant - transparent, regular shaped cells with chloroplasts for photosynthesis - prevent water getting out and stopping unwanted substances/organisms getting in. - not many mitochondria because they don’t require a lot of energy

Answer 51

Cilia, external - lines cavities (e.g. airways) (animal) - cilia all beat together to move mucous and trapped particles up&out of the trachea - prevents aspiration (particles entering lungs and causing infection)

Answer 52

- connect sensors to the brain (animal) - long length for transmitting signals over a long distance quickly (GO OVER STRUCTURE)

Answer 53

Mitosis: growth, replace worn out cells, repair damaged tissue Meiosis: sex cells

Answer 54

Differentiation is the ability of cells to become different shapes or sizes to carry out specialised jobs

Answer 55

A unicellular organism depends upon just one cell for all of its functions while a multicellular organism has cells specialized to perform different functions that collectively support the organism. therefore multicellular… - can grow larger - more complex

Answer 56

1. All organisms are made of cells 2. All existing cells are produced from a previous cell 3. A cell is the most basic sub-unit of life.

Answer 57

23 pairs, 46 chromosomes in total. Homologous.

Answer 58

Sex cells. Because they will be paired with egg cell/ sperm cell that gives them the other half.

Answer 59

Genetically identical.

Answer 60

A cilium, or cilia (plural), are small hair-like protuberances on the outside of eukaryotic cells. They are primarily responsible for the movement of the cell or fluids on the cell surface., either of the cell itself or of fluids on the cell surface.

Answer 61

A hairlike external body part that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility.

Answer 62

When the concentration gradient is 0- isotopic solutions.

Answer 63

Mitosis and meiosis both involve cells dividing to make new cells. This makes them both vital processes for the existence of living things that reproduce sexually. Meiosis makes the cells needed for sexual reproduction to occur, and mitosis replicates non-sex cells needed for growth and development.

Answer 64

1. Each chromosome is copied (DNA replication) 2. Cell resting 3. Spindle forms. Chromosomes arranged along the equator. 4. Chromosome single strands get dragged to the poles of the cell. 5. Two genetically identical cells are produced

Answer 65

Cell type: N/A Organism type: bacteria

Answer 66

Epidermal cell

Answer 67

6CO2+6H2O→C6H12O6+6O2

Answer 68

- Control gas diffusion by regulating opening and closure of stomatal pores - Found in the epidermis layer of plant STOMATA function: controls the rate of gas exchange, amount of water loss and gas loss is controlled by pore size and pressure

Answer 69

Lots of water -> root hair cell -> stem -> xylem -> fills large central vacuole of stomata and pushes it open -> water loss by vapour

Answer 70

- dead tissue - function: transports minerals and water from root to stem of the leaf - function: provides physical support for the plant - found in all vascular plants and all flowering plants - transpiration

Answer 71

Cohesion Cohesion draws up water to top for photosynthesis

Answer 72

Water evaporating via passive movement

Answer 73

- function: transport and distribution of sugars and organic nutrients produced by photosynthesis - translocation - A high concentration of organic substances, particularly sugar, inside cells of the phloem at a source, such as a leaf, creates a diffusion gradient (osmotic gradient) that draws water into the cells from the adjacent xylem. This creates turgor pressure, also known as hydrostatic pressure, in the phloem.

Answer 74

Locomotion

Answer 75

- stomata in a small pit - embedded into the leaf layers rather than on the surface of the leaves - protects against the escaping water vapor from air currents - decreasing water loss from the leaf - decreasing transpiration

Answer 76

Multicellular: Lysosome for waste disposal Smaller SA:V ratio (compared to unicellular organism Slower diffusion rate Complex structures to obtain substances like co2 for survival Complex transport systems are necessary Osmoregulation done by homeostatic processes --------------------------------------------------------- Unicellular: Disposes of waste substances with diffusion Very big SA:V ratio compared to multicellular organism High diffusion rate Relies on diffusion for survival No need complex transport systems as diffusion rate is high Osmoregulation with contractile vacuole

Answer 77

Amoeba, paramecium, euglena

Answer 78

A cell with the ability to differentiate into al the types of cells in the human body.

Answer 79

- Switches off all the other genes except for the gene of the specialisation it wishes to have

Answer 80

1. The substance is being transported against its concentration gradient (low concentration to high concentration.) 2. a charged particle unable to be moved across the membrane 3. substance y is too large to pass through the phospholipid bilayer.

Answer 81

have/ don’t: have membrane bound organelles have/ don’t: have distinctive nucleus

Answer 82

Microvilli increased SA:V ratio of the cell which leads to an increased diffusion rate.

Answer 83

- temperature - SA:V ratio - thin membrane

Answer 84

- hypotonic/ hypertonic - type of diffusion, what happens with substance movement - direction of movement - reason for more/ less beating - refer to specific data Distilled water is more hypotonic compared to pond water. Therefore, more water enters the cell by osmosis, from a low to high concentration (1). The contractile vacuole must beat faster to remove the excess water (1

Answer 85

- hypotonic/ hypertonic/ isotonic - type of diffusion, what happens with substance movement - direction of movement - reason for less/more/no beating - refer to specific data As the salt concentration of the solution increases, it becomes less hypotonic. Therefore, less water enters the cell by osmosis (1). Less water needs to be expelled out of the cell, so the contractile vacuole beats at a lower rate (from 3.3 to 1.5 bpm

Answer 86

- hypotonic/ hypertonic/ isotonic - type of diffusion, what happens with substance movement - direction of movement - reason for less/more/no beating - refer to specific data At 0.25% the solution becomes isotonic to the cell. There is no overall net movement of water (1) into or out of the cell. The volume of the cell remains constant and the contractile vacuole does not need to beat (1).

Answer 87

Cell A would have the highest SA: V ratio due to its villi/ microvilli, which maximizes its absorption of food.

Answer 88

Palisade cells. Its square/ rectangle structure allows it to stack tightly against each other. It has chloroplasts that conduct photosynthesis, where its stacking structure allows the plant to grow taller in order to maximize exposure to light.

Answer 89

Chloroplast conducts photosynthesis and produces glucose as a product. Glucose contributes to the osmotic gradient, added turgor increases pressure on the guard cell and opens the stomata.

Answer 90

The movement of potassium ions increases the solute concentration of the guard cell, causing osmosis to occur in order to achieve isotonic equilibrium. This leads to the cell swelling up and increasing turgor pressure, opening up the stomata.

Answer 91

- increase occurs when... - concentration gradient and rate of diffusion (connection between them) - when temp is different... - more molecular activity= higher rate of diffusion Z (½). An increase in the rate of diffusion occurs when the concentration of solute is higher or when the solute is the most/very hypertonic to the beaker (½). The greater the concentration gradient/ difference in concentrations (½) the faster the diffusion/ osmosis. When the temperature/ temperature difference is highest (½), the more kinetic energy (½) and the rate of molecule activity would increase (½) the higher the rate of diffusion.

Answer 92

Organism D has a much smaller SA:V ratio compared to C, therefore it also has a much smaller diffusion rate. This can be beneficial in a poisonous solution, where the slower absorption rate of poison delays its impact. Where it would also be beneficial in a cold situation, where heat would be lost at a slower rate. (organisms with larger SA:V ratio would have to use lots of energy to keep themselves warm as their heat loses faster.

Answer 93

(DRAW Measured longest length/ DRAW length of scale)*scale FOV length

Answer 94

C and D have the same shape but largely different sizes. C is much smaller than D but has a much larger SA:V ratio due to its size. Therefore C would turn red much more quickly than D when placed in a red dye solution as it has a much higher diffusion rate.

Answer 95

Water reaches these cells by cohesion through the root hair cell where it is absorbed from the soil to the xylem, and finally to the guard cell.

Answer 96

- need to be near the stomata to collect Co2 and water for photosynthesis - as well as being at the surface (upper part) of plant to collect as much sunlight as possible.

Answer 97

at time R the one cell has completely split cytokinesis(1/2) and formed two new cells so the existing cell has now the same amount of DNA as it began with.

Answer 98

(a) In cell B and C osmosis has occurred (½) which is the movement of water from a dilute solution to a stronger solution through a semi permeable membrane (1). The plant cell B and C is evidently in a hypertonic solutions (½)) It has lost water due to osmosis shown by the shrinking of its large vacuole. (1) C had a stronger concentration gradient so lost more water compare with B in the same time frame (1 minute). (1)

Answer 99

(b) In red blood cells the 1% solution (B) would have been close to isotonic for the red blood cell and as such little change in water across the membrane would have been evident. In (A) solution fresh water would be an example of a Hypotonic solution and water would move into the cell by osmosis. This would continue until the cell would burst. (1) In solution C at 5% saline it is a hypertonic solution with reference to the cell and as such water would move out of the cell and cause it to shrivel up. (1)

Answer 100

(a) Structure 1: Cell membrane & Structure 3 is cell wall / capsule (1 mark). Differences in function: Cell membrane controls exchange of substances between the cell and its external environment (1 mark), whereas cell wall provides structural support and protection (which is enhanced by capsule especially) (1 mark).

Answer 101

Cell B is prokaryotic ( mark), Evidence: lacks membrane bound organelles (although this is hard to tell due to nature of diagrams), nuclear material not in a membrane bound nucleus, presence of capsule surrounding the bacterium (1 mark for each), Up to 1 mark for mentioning that bacteria are prokaryotic organisms while humans are not.

Answer 102

Cell A is suited to its function – cilia projections (micro – hairs) (1/2) on the edges of the cell filter the air by trapping debris such as dust, bacteria and other foreign matter from going into the lungs. (1) Directs the flow of air down the passage and foreign matter the opposite direction. (1/2) and gives protection. (students may mention mucus secretions by goblet cells but they are not pictures and we have not taught this yet.)

Answer 103

- ‘Cells exchange materials and wastes in an aqueous/interstitial fluid environment across a plasma membrane (1). - Concentration gradients and dissolved substances help increase the rate of exchange (1)’. - The complexity of an organism is largely due to its SA: Vol ratio (½). - An effective exchange with the environment requires sufficient material (nutrients such as glucose, gases O2 & CO2) to cover the whole body (½) and removal of waste (½), at a certain rate. As the volume of a cell increases so does the surface area but at a much smaller rate (½), hence creating a smaller SA: Vol ratio(½). - As the SA: Vol ratio decreases the efficacy of diffusion also decreases (½)as it takes longer for important nutrients to diffuse to all parts of the cell to keep it alive (as well as removal of waste). - Therefore, size becomes a limiting factor. (½) UNICELLULAR organisms are small in size and have an effective exchange rate (high rate of diffusion) (½) across a plasma membrane due to a large SA: Vol ratio and short diffusion distance (1). - Living in an aqueous environment requires specialised process such as osmoregulation or osmo-conforming, cilia or flagellum for movement (½) and transport processes (endocytosis, exocytosis) to maintain a homeostatic balance. (½) Multicellular organisms are larger and have smaller SA:V ratio (½) therefore with groups of cells (skin, muscle, blood, nerve etc.) (½) differentiating to take on work together (specialised functions) they can carry out metabolic processes and increase SA: V. (½) The metabolic process requires specialised cells and in most cases a transportation/circulatory system (½) (for movement of nutrients, gases and waste) (½) to carry out their function efficiently. Cells that require a large amount of diffusion to occur such as intestinal epithelium cells contain microvilli to increase the surface area (½) or red blood cells (specialised shape) have a biconcave shape to increase SA:V ratio hereby increase functionality (½), they will have a much larger SA: Vol ratio then storage cells (fat cells) that do not wish to lose what they are storing(½). Muscle cells require more mitochondria to carry out cellular respiration (½)to provide ATP for movement (½), white blood cells to fight infections belonging to the lymphatic system (½).

Answer 104

As ribosomes are the site of protein synthesis (1), binding of tetracycline must stop this process. If the bacteria cannot make the proteins it needs (½) (such as enzymes needed in cellular reactions (½)), this must lead to death of the bacterial cell.

Answer 105

Diagram C shows 2 daughter cells forming (1) marks * 2 daughter cells form, whereas in meiosis 4 haploid cells form (1) mark * There is only 1 round of cell division, meiosis undergoes 2 cell divisions (1) mark * Identical daughter cells (½) or genetically identical daughter cells (1) * Splits into two (½) mark * If correct comparison with meiosis (½) mark

Answer 106

Enzymes are proteins (½). RER is the site where mRNA is read by ribosomes (three nucleotides at a time) as the code is translated into polypeptides or proteins (1). The RER then acts as channel for the proteins to move along towards the Golgi (½). The Golgi is where the polypeptides may be combined into proteins, (½) or the already formed proteins are packaged into vesicles for transport in or out of the cell (½).

Answer 107

To distinguish between diffusion and osmosis: the diagram would need to show water molecules moving down their concentration gradient by osmosis (½). There would have to be solute concentrations identified on each side of the membrane to determine which direction the water molecules would move (1). For diffusion: gas or solute molecules (½) would need be in different concentrations on either side of the membrane and arrow showing movement down their concentration gradient (1) Different proteins identified – aquaporin for water molecules to move through by osmosis or channel protein for charged ions or larger nutrients/solutes to diffuse through (1).

Answer 108

dna, nuclear membrane, plasmid, ribosomes

Answer 109

dna, nuclear membrane, vacuole, ribosomes

Answer 110

Any plausible reasoning such as: Algae are eukaryotic cells as they have a defined nucleus and membrane bound organelles. (1) Algae are not animal cells as they have a cell wall and chloroplasts (½), they are not plant cells as they have a contractile vacuole (½), they are likely to be neither and be a different classification such as protists (½).

Answer 111

Size: As the size of a cell increases, its volume increases much faster (x3 ) than its surface area (x2 ). The smaller the cell, the greater its SA:Vol ratio and the more efficient it is at exchanging materials. At some particular size, the surface area will not allow the exchange of sufficient materials to supply the needs of all the organelles which make up the volume of the cell. This limits the size of the cell and explains why cells are usually microscopic. Shape: A sphere is the shape with the lowest SA:Vol ratio and is the least efficient at exchanging materials. Any change in this shape (elongating, flattening, the presence of microvilli etc.) will increase both the SA:Vol ratio and the efficiency of the cell. The function of a cell may also determine its shape. Specialized cells that function to absorb material (e.g. the cells that line the small intestine) or excrete material (e.g. kidney cells) have a larger SA:Vol generally due to modifications like microvilli. Photosynthetic cells tend to be long and thin which enhances SA:Vol ratio. Active animal cells are smaller than less active cells or plant cells. Examples can be given here. Some cells are specialized to have limited exchange of materials such as adipose tissue which stores fat, dormant eggs in the ground or even some seeds. These have a low SA:Vol ratio and are often spherical.

Answer 112

The process is osmosis (½) because the RBC is swelling/ increasing in volume/ the solution is entering the cell (½). The solution is moving from the hypotonic/ low solute conc./ high water conc. (½) to the hypertonic/ high solute conc. / low water conc. Inside the RBC (½) until equilibrium/isotonic environment is reached (½) or the RBC burst (haemolyse) (½).

Answer 113

Plant cell walls are made of cellulose and bacterial cells are made of polysaccharides and amino acids (peptoglycan = murein) or are made of different material to bacterial cells (1). The plant cell wall limits the size that the cell can swell to and therefore the amount of water it can absorb, preventing it from bursting (1).

Answer 114

. B (½) Crossing over mixes (½) up chromosomal material. This increases genetic variability (½) in the gametes and ultimately the offspring. This results in offspring that are different to their parents and each other (½). [other variations were awarded marks providing the idea being expressed was the same].

Answer 115

In the green part of a plant, a leaf or stem. It is a plant cell because of the presence of the thick rigid cell wall to provide support. A large vacuole as reservoir of water and metabolites/ or to provide turgor/ or any reasonable function. Chloroplasts needed for photosynthesis. ½ mark each.

Answer 116

Feature Bacteria Viruses Capsid A P Cell wall P A Flagellum P A Plasma P A

Answer 117

Virus: have a protein coat (capsid) surrounding it for protection (1 often have spikes that allows it to stick to host cells(1 covered in surface proteins that allows it to enter and exit a host cell (1 contain DNA or RNA that allows them to replicate on a host cell (1 extremely small allowing them to infiltrate host cells easily and replicate in large numbers (1 Bacteria: contains ribosomes to make proteins (1 cell wall giving protection (1 capsule coated cell wall protecting against antibiotics (1 very small for high sa:v ratio for fast diffusion of materials (1 contains plasmids with genes that enhance survival of bacteria (1 shape of some allows stacking, to take up area efficiently when multiplying (1 extremely small, enabling easy entrance into body (1

Answer 118

Cells need to exchange materials such as nutrients and waste products with their environment through their cell membrane (1). A cell with a larger volume must support this with more metabolic activity. (1) A large SA:V means more capacity for material exchange as there is more surface area supporting the volume (1), with smaller diffusion distances (1). This is particularly important for cells that have a secretory role (such as those secreting enzymes) or absorption role (intestinal epithelium) that have higher metabolic rates (1). A small SA:V would be more beneficial to cells storing substances (such as fat/adipose cells), with a lower metabolic rate, as they need to contain material and not exchange it (1). At least two examples of cells needed to be included for full marks.

Answer 119

The cell membrane is selectively permeable and regulates what enters and leaves the cell. Through active transport the membrane controls the concentration of nutrients and ions within the cell by selecting which substances enter and leave and is therefore responsible for regulating the cell's internal environment.

Answer 120

The nuclear membrane separates the DNA from the rest of the cell. *The endoplasmic reticulum provides a transport system. *The cristae of the mitochondria provide a large surface area on which the reactions of respiration can occur. *Compartmentalisation allows a large number of activities to proceed simultaneously. Any two of the above or any two other appropriate examples were accepted.

c6 cell organism test Flashcards

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