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Biology iGCSE > B1 and B2 - Characteristics of Living Organisms and Cells > Flashcards

B1 and B2 - Characteristics of Living Organisms and Cells Flashcards

1
Q

Characteristics of life: MRS GREN

A
  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
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2
Q

Movement

A

An action by an organism or part of an organism causing a change of position or place

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3
Q

Sensitivity

A

The ability to detect or sense stimuli in the internal or external environment and to make appropriate responses

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4
Q

Respiration

A

The chemical reactions that break down nutrient molecules in living cells to release energy for metabolism

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5
Q

Growth

A

A permanent increase in size and dry mass by an increase in cell number or cell size or both

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6
Q

Reproduction

A

The processes that make more of the same kind of organism

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7
Q

Excretion

A

Removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirements

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8
Q

Nutrition

A

Taking in of materials for energy, growth and development; plants require light, carbon dioxide, water and ions; animals need organic compounds and ions and usually need water

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9
Q

Parts of an animal cell

A

Nucleus, cytoplasm, cell membrane, mitochondria

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10
Q

Parts of a plant cell

A

Cell wall, cell membrane, cytoplasm, mitochondria, chloroplasts, vacuole

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11
Q

Function of nucleus

A

Directs all the cells activities; contains the cells DNA

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12
Q

Function of cell membrane

A

Partially permeable membrane which controls substances that move in and out of the cell

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13
Q

Function of chloroplasts

A

Structures found in the cells of green parts of plants only (leaves and stems) which contain a green pigment called chlorophyll in which photosynthesis occurs

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14
Q

Function of vacuole

A

Stores materials such as water, salts, proteins and carbs

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15
Q

Function of rough endoplasmic reticulum

A

Membrane-bound structure involved in protein synthesis; covered in ribosomes and forms around the nucleus

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16
Q

Function of cytoplasm

A

Liquid that makes up most of the cell in which chemical reactions happen

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17
Q

Function of mitochondria

A

Floating in the cytoplasm where energy is released from glucose from food; where most respiration happens

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18
Q

Function of cell wall

A

A tough outer layer of the cell, which contains cellulose to provide strength and support to the plant

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19
Q

Function of ribosomes

A

Protein synthesis (making proteins)

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20
Q

Function of enzymes

A

Biological catalysts, increase rate of chemical reactions

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21
Q

Solute

A

A substance that is dissolved in a solvent

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22
Q

Solvent

A

The substance in which the solute dissolves

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23
Q

Soluble

A

A substance able to dissolve

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24
Q

DNA

A

Contains genetic information for the building and functioning of the cell

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25
Electron microscope
Microscope that forms an image by focusing beams of electrons onto a specimen
26
Light microscope
Microscope that uses a beam of light passing through one or more lenses to magnify an object
27
Nosepiece
Holds the objectives and can be rotated to change the objective lens to the specific lens one you want to use
28
Diaphragm
Controls the amount of light passing through the slide; located below the stage and is usually controlled by a round dial
29
Illuminator
Low voltage bulb which supplies light through the stage and onto to the specimen (sometimes mirrors)
30
Solution
The final product of dissolving (solute + solvent)
31
Eyepiece (ocular lense)
Magnifies an image, usually 10x
32
Eyepiece tube / body tube
Holds the eyepieces in place above the objective lens
33
Objective lense
Most compound microscopes come with three or four objective lenses that revolve on the nosepiece (low, medium, high) The most common objective lenses have power of 4X, 10X and 40X
34
Arm
The Arm connects the base to the nosepiece and eyepiece; also used to carry the microscope.
35
Stage
Where the specimen is places; supports the slide being observed
36
Stage clips
Holds the slide in place on the stage
37
Coarse focus
Knob that allows you to make major focusing adjustments (large knob)
38
Fine focus
Knob that allows you to make fine focusing adjustments in smaller increments (small knob)
39
Base
The main support of the microscope
40
Magnification equation
Magnification = Image size ÷ Actual size
41
Image size equation
Image size = magnification x actual size
42
Actual size equation
Actual size = image size ÷ magnification
43
Magnification of light microscope equation
Magnification of light microscope = Magnification of eyepiece lens × Magnification of objective lens
44
Specialisation
The adaptation of an organism or organ to a special function or environment
45
Ciliated epithelial cell function
Move dust and bacteria trapped in mucus out of the windpipe
46
Ciliated epithelial cell adpatations
Small projections called 'cilia' to move mucus up the windpipe - the mucus is produced by the goblet cells within the epithelial cell - the sticky mucus traps particles, pathogens like bacteria or viruses and dust
47
Sperm cell function
To fertilise the egg cell
48
Sperm cell adaptations (4)
- Flagella to help it swim - Mitochondria to release energy for swimming - Acrosome contains chemicals to break down egg membrane - Only half the DNA needed for a new person in nucleus
49
Egg cell function
To be fertilised and grow into an embryo
50
Egg cell adaptations (4)
- Lots of cytoplasm for cell division - Only half the DNA needed for a new person in nucleus - Cytoplasm contains nutrients for growth of the developing embryo - Jelly membrane forms impenetrable barrier so no more than one sperm can fertilise
51
Root hair cell function
To absorb water and minerals from the soil
52
Root hair cell adaptations (4)
- Large surface area - increases the rate of the absorption of water by osmosis and mineral ions by active transport - Lots of mitochondria to release energy (sometimes needed to absorb minerals) - No chloroplast - Thin cell wall for quick and easy water movement
53
Red blood cell function
Transport oxygen
54
Red blood cell adaptations (4)
- Large surface area due to biconcave shape - No nucleus (so more space for oxygen) - Contains haemoglobin - Small and flexible to fit through tiny blood vessels
55
Palisade cell function
To carry out photosynthesis
56
Palisade cell adaptations (2)
- Lots of chloroplasts - increase rate of photosynthesis - Large surface area to absorb light
57
Net movement
The movement of all the particles considered together as a group - not individual particles
58
Active movement
The movement of molecules from an area of low concentration to high concentration with the use of energy (ATP) - they move against their concentration gradient (absorption) and so need additional energy
59
Passive movement
The random movement of molecules across a membrane without the input of energy, from a high concentration to a low concentration
60
Osmosis
The net movement of water molecules from a region of higher concentration to a region of lower concentration across a partially permeable membrane
61
Diffusion
The net movement of particles from an area of higher concentration to an area of lower concentration
62
Molecules that generally can diffuse through a partially permeable membrane (3)
water, glucose, amino acids
63
Molecules that generally can't diffuse through a partially permeable membrane
protein, starch
64
Partially permeable membrane
A membrane that allows only certain (smaller) particles to diffuse through it
65
Factors of diffusion (5)
* medium/state * distance of travel * concentration gradient * surface area : volume * temperature
66
How does the concentration gradient affect diffusion?
Difference in the concentration of a substance between 2 places - steep (greater difference): increase - not steep (smaller difference): decrease
67
How does the medium/state affect diffusion?
The difference in rate of diffusion if a substance is liquid or gas - liquid: decrease (slower) - gas: increase (faster)
68
How does the distance of travel affect diffusion?
The distance molecules have to travel through the membrane - longer distance: decrease (slower) - shorter distance: increase (faster)
69
How does the surface area affect diffusion?
The greater the surface area, the more space there will be for particles to diffuse - large surface area: increase (faster) - smaller surface area: decrease (slower)
70
How does the temperature affect diffusion?
The temperature provides more kinetic energy to the particles, making them move faster - high temperature: increase (faster rate) - low temperature: decrease (slower rate)
71
Dilute solution
Contains high concentration of water molecules
72
Water potential
The quantity of water molecules within a substance
73
Concentrated solution
Contains low concentration of water molecules
74
What does more water mean in terms of water potential?
More water = higher water potential
75
What does less water mean in terms of water potential?
Less water = lower water potential
76
Metabolism
The chemical processes that occur within a living organism in order to maintain life
77
Turgor pressure
The pressure that water molecules exert against the cell wall - cell wall helps plant cells from bursting
78
3 stages of osmosis in animal and plant cells
Hypertonic, Isotonic, Hypotonic
79
Hypertonic plant cells
Cells placed in a solution with a low water concentration compared to their contents (concentrated sugar solution) will lose water by osmosis - called plasmolyzed
80
Isotonic plant cells
The solution which it is placed in has equal concentration of solutes so water diffuses by osmosis in and out of the cell - called flaccid
81
Hypotonic plant cells
Plant cells placed in a solution with a high water concentration compared to their contents (eg water) will gain water by osmosis and swell up - called turgid
82
Hypertonic animal cells
Red blood cells placed in a solution with a lower water concentration compared to their contents (eg 1.7 percent salt solution) will lose water by osmosis and shrink - called crenated
83
Isotonic animal cells
Normal cell, balance concentration of water
84
Hypotonic in animal cells
Red blood cells placed in a solution with a higher water concentration compared to their contents (eg pure water) will gain water by osmosis, swell up and burst - called lysis

Biology iGCSE (13 decks)

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