Prelims (Mod 1-4) Flashcards
1
Q
organic chemicals
biomacromolecules
A
based on carbon, hydrogen, and oxygen, many are polymers made by joining many smaller molecules
carbohydrates
lipids
nucleic acids (nitrogen and phosphorus)
proteins (nitrogen and maybe sulfur)
2
Q
use of carbon dioxide and oxygen in cell
A
reactants and products in biochemical processes
3
Q
use of mineral salts in cell
A
co-enzymes that help enzymes speed chemical reactions
Cl and Na ions needed for cell membrane function, nerve, muscle cell functioning
calcium salts needed for bones and teeth
iron needed for red blood cells
4
Q
use of water in cell
A
transport medium for substances inc ell
solvent, substances dissolve in it
reactant and product in chemical processes
5
Q
inorganic chemicals
A
water: hydrogren and oxygen
mineral salts (ions): K+, Cl-
Carbon dioxide: carbon and oxygen
6
Q
function of lipids
A
used as a way to store excess energy
all cell membrane are built from lipids
can be broken down and used in respiration to produce energy
7
Q
lipids
A
carbon, hydrogren, oxygen
fats and oils
1 glycerol molecule + 3 fatty acid chains
contains more than twice the energy of carbohydrates
8
Q
carbohydrates
A
carbon, hydrogren, oxygen
sugars, starch and others
monosaccharides= glucose
disaccharides= sucrose (table sugar)
polysaccharides= (many) starch, glycogen (made by animals to store sugar), cellulose
9
Q
uses of carbohydrates
A
sugars: energy chemical, fuel for cellular respiration (ATP)
starch & glycogen: polymer molecules used to store sugar as food reserve
cellulose & lignin; polymers of sugar used structurally by plants
10
Q
nucleic acids
A
2 types: DNA and RNA
basic unit: nucleotide
DNA: deoxyribonucleic acid, genetic information stored in chromosomes, controls cell functions and organism characteristics
RNA: ribonuleic acid, needed for protein synthesis
DNA is polymer of sugars, phosphate, nitrogen bases in double helix shape
11
Q
function of proteins in chemicals in cells
A
needed for body growth and repair
e.g. ezymes, hormones
12
Q
proteins
A
main structral chemical of organelles
polymers made from amino acid molecules chained together
most abundant organic molecule in the shell
13
Q
head of phospholipid bilayer
A
hydrophilic phosphate head
14
Q
tails of phospholipid bilayer
A
hydrophobic fatty acid tails
15
Q
fluid mosaic model
A
describes the cell membrane as a double layer of lipids, a lipid bilayer, with the ability to flow and change shape, like a two-dimensional fluid. Specialised protein molecules are
embedded in the lipid in various patterns like a mosaic. Both proteins and phospholipids help to control the exchange of materials
between the external and internal environments.
16
Q
where is cholesterol located on the cell membrane
A
interspersed among the phospholipid molecules in animal cells. This makes the membrane more flexible.
17
Q
membrane proteins
A
adhesion, transport, recognition, receptor
18
Q
adhesion protein
A
link cells together and help maintain the organism’s three-dimensional structure.
19
Q
transport protein
A
passageways that allow specific substances to move across the membrane.
21
Q
recognition proteins
A
or glycoproteins are made up of a protein molecule with a
carbohydrate molecule attached. These proteins identify the cell and are called antigens or marker
molecules. They allow the immune system to distinguish between foreign particles (‘non-self’) and the body’s own (‘self’) cells.
21
Q
receptor protein
A
cause the cells to respond only to certain signals from substances such as hormones that bind to them, giving them specific functions.
22
Q
What goes in and out of a cell
A
in: glucose, water, salts, oxygen
out: urea, carbon dioxide, water, salts
23
Q
what does permeability depend on
A
molecules size, electrical charge, lipid solubility
24
Q
diffusion
A
net movement of molecules from a region of high concentration to a region of low concentration of that substance, until equilibrium is reached
25
what influences th rate of diffusion
heat since kinetic energy makes the particles move more, temperature can slow or speed the rate
26
examples of simple diffusion
oxygen and carbondioxide
27
facilitated diffusion
large molecules (glucose or amino acids) or charged particles (ions) trequire certain proteins called
carrier proteins and channel proteins in the cell membrane to assist them in diffusing into the cell.
28
how does the cell membrane diffuse large molecules over
carrier proteins
29
how do ions diffuse over cell membrane
channel proteins
30
osmosis
the process by which water moves through the cell membrane
the movement of water molecules through a semi-permeable membrane from a region of high water concentration to a region of low water concentration
31
dilute solution
contains a small amount of solute in relation to the amount of water and the water is said to be in high
concentration.
32
a solution of 1% salt/sugar
has the same water and salt/sugar concentration as an average cell
33
hypertonic
higher salt/sugar concentration and a lower water concetration than a cell
34
hypotonic
lower salt/sugar concentration and a higher water concentration than a cell
35
isotonic
same salt/sugar concentration and the same water concentration as a cell
36
animal cells when surrounding solution is hypotonic
haemolysis (swells and bursts)
37
animal cells when surrounding solution is hypertonic
shrinks
38
plant cell when surrounding solution is hypotonic
turgid
39
plat cells when surrounding solution is hypertonic
plasmolysis
40
active transport
movement of molecules from a region of low concentration to a region of high
concentration, and requires the input of energy. against concentration gradient
requires a carrier protein that spans the membrane to actively move chemicals from a low to a high concentration, utilising cellular energy
41
endocytosis
When a large particle has to be moved into a cell, the cell membrane can change its shape to surround the particle and engulf it
requires energy
42
phagocytosis
if solid particle is engulfed by cell membrane
43
pinocytosis
when liquid is engulfed by cell membrane
44
exocytosis
process by which these substances are transported to the external
environment of the cell. in an membrane vesicle
requires energy
45
factors affecting exchange of materials across membrane
chemical factors (being soluble in lipid), physical factors (size of particle), concentration gradient, SA:V ratio
46
high SA:V ratio
smaller cell has more surface area in relation to its volume
47
low SA:V ratio
A larger cell has a smaller amount of surface area in relation to its volume
48
function of carbohydrates
sources of quick energy, break down to glucose and convert into energy in respiration process
49
function of lipids?
used as a way to store excess energy
all cell membrane are built from lipids and proteins
50
what does denatured me?
when a protein's shape alters when heated too much or wrong pH environment
51
use of carbon dioxide and oxygen in cell
reactants and products in biochemical processes
52
use of carbon dioxide and oxygen in cell
reactants and products in biochemical processes
53
use of carbon dioxide and oxygen in cell
reactants and products in biochemical processes
54
what are the two stages of photosynthesis and what are their main products
light dependent stage( hydrogen) and light-independent stage (glucose)
55
cholesterol and phytosterols
(in animals) or (in plants) provide some flexibility to the membrane.
56
what makes the rate of diffusion quicker
higher temperature and steeper concentration gradient
57
where is the recognition protein
pheriperal membrane
58
where are transport proteins
transmembrane
59
where are adhesion proteins
transmembrane
60
where are receptor proteins
transmembrane
61
cellular wastes
CO2: from CR, eliminated through respiratory system
Urea (nitrogenous waste: from digestion of proteins, eliminated by excretory system
Lactic acid: from anaerobic respiration (fermentation of acid), eliminated by liver
Hydrogen peroxide: from metabolic processes, eliminated by peroxisomes
Ethanol (alcohol): from fermentation in yeast and plants, eliminated by diffusion
Hydrogen sulfide: anaerobic cellular respiration (prokaryotes), eliminated by diffusion
62
photosynthesis equation
Carbon dioxide + water → oxygen + glucose +ATP
63
Cellular respiration equation
Oxygen + glucose → carbon dioxide + water + ATP
64
CR waste product
Carbon dioxide
65
Photosynthesis waste product
oxygen
66
Types of CR
Aerobic: presence of oxygen, complete breakdown of glucose, more ATP
Anaaerboic: absence of oxygen, partial breakdown of glucose, less ATP
67
Enzymes
Protein molecules that control metabolic reactions, act as biological catalysts
68
Production of enzymes
Present in the cytoplasm of a cell, produced by ribosomes
69
Composition of enzymes
Globular proteins, consisting long chains of amino acids folded into specific shape
Polypeptide chain (consisting of amino acids)
Contains specific active site and catalyses a distinct chemical reaction
Molecule on which enzyme acts is called substrate
70
Types of enzyme reactions
Anabolic reaction: combining of two simpler substances to form more complex substances
Catabolic reaction: the breakdown of large, complex substances into smaller simpler ones
71
Example of an anabolic and catabolic reaction
Anabolic: photosynthesis making glucose
Catabolic: cellular respiration breaking glucose down
72
Two types of models to describe how enzymes work
Lock and key model: the active site of the unbound enzyme is precise in shape to the substrate
Induced fit model: the enzyme changes shape on contact with the substrate. When the substrate (or its products) is released the enzyme returns to its original form/shape.
73
Factors affecting enzyme activity
Temperature
Enzyme have an optimal temperature
Becoming too hot or to cold: denaturation
Denaturation: active site changes shape so the substrate can no longer bind
pH
The optional pH is different for different types of enzymes depending on their environment
In body optimal pH between 6-8
Enzyme activity can decrease further from optimum pH
The pH changes bonds that give enzyme its 3D tertiary structure
bonds become disrupted and shape of enzyme changes
Substrate concentration
Number of reactions is limited to number of available enzymes
The substrate concentration increase, the chemical reaction will increase, more substrate becoming occupied by free enzymes
When concentration is higher than of enzymes, rate of reaction can no longer increase (point of saturation), no effect if all active sites are occupied
74
Multicellular organism
Require system for nutrients and waste removal
Different cells specialise to perform different functions
75
characteristics that enable them to overcome the problems of their large overall size
1. Each cell which makes up the multicellular organism is itself very small.
2. Each cell in the multicellular organism has a specialised structure and function.
3. Many cells work together in a coordinated fashion to keep the organism alive.
4. The multicellular organism has a longer lifespan than a unicellular organism.
76
Unicellular organisms
Using diffusion, osmosis and active transport to take nutrients and remove waste through cell membrane
77
Colonial organisms
Individual cells living in a colony
Individually carry out metabolic functions
Simple specialised cells within the colonial organisms can improve efficiency of overall functioning
78
Importance of specialised cells
Each cell cannot perform every function (MRS GREN) in order for organism to survive
This would be waste of nutrients, energy and processes would be slower
Increases efficiency and utilisation of biological resources
79
Location of stem cells
In the embryo (embryonic stem cells)
In the human brain and bone marrow (adult stem cells)
Plants → In meristematic tissue, young growing regions like roots, shoot tips
80
Red blood cell structure, function, relationship between the two
Flat disk/doughnut shape, which is round with an indentation in the centre, but isnt hollow
Lacking nucleus
To carry oxygen to cells and carbon dioxide away from cells/tissues
Disc shaped- fits more easily through small capillaries. No nucleus to free up space to hold more oxygen. Many mitochondria to power the movement around bloodstream
No nucleus allows change in shape and move through body easier
81
Root hair cells structure, function and relationship between the two
Long tubular shaped outgrowths from root epidermal cells
To absorb water and nutrients from the surrounding soil
The projection of the root hair increases the SA over which water can be absorbed by the roots
82
Squamous cells in Alveoli structure function and relationship between the two
Large, flattened cells
Smooth surface
Lines internal organs, protecting them by secreting lubricating fluid
Secrets lubricating substance in heart
Oxgyen and CO2 must diffuse across the cells of the alveoli into the lungs
Single layer of flattened cells make up the alveoli walls- this reduced the distance over which the gases have to diffuse, hence diffusion is faster
83
Palisade cells in leaf tissue structure, function and relationship between the two
Cells are packed tightly together and contain chloroplasts
Contains largest number of chloroplasts per cell
Chloroplasts in the palisade cells is the site of photosynthesis
Being close together maximise light absorption
Many chloroplasts help maximise energy transfer, conversion of light to chemical energy
The palisade cells are round in upper layer of the lead which is the layer exposed to sunlight. This enables the leaf to make the most of sunlight failing on its surface.
84
Examples of hierarchy of multicellular organisms
Mitochondria → cell → cardiac muscle tissue → ventricular muscle heart → circulatory system → human
Axon → motor neutron → motor nerve → sympathetic nervous system → nervous system → frog
Chloroplast → spongy cell → spongy mesophyll → leaf → foliage → tree
Beta cell → pancreatic tissue → pancreas → endocrine system → organism
85
Organic substances
glucose, amino acids, fatty acids, glycerol, nucleotides, vitamins
86
Inorganic substances
phosphates, sodium, chloride ions, and water
87
Autotrophs
organisms that can produce their own organic nutrients and need to obtain water, mineral ions and the gases carbon dioxide and oxygen from external sources (producers)
88
Vascular autotrophs
Plants with a transport system for support and movement of substances
89
Non-vascular autotrophs
Without a transport system providing support or moving substances
osmosis and diffusion is used to receive and eliminate wastes
90
Heterotrophs
organisms that cannot produce their own food, services its nutrition from other sources (consumers)
91
3 organs of a plant
Shoot, root, vascular systems
92
4 types of tissues in plants
meristematic, dermal, vascular, ground tissue
93
meristematic tissue
| found?, function
Found at the tips of roots and shoots
Function: Cells divide in meristematic tissue to produce new cells and therefore growth
Cell differentiation can also take place to produce specialised cells
94
Dermal tissue
| function
Function: protects the plant tissues from damage and controls interactions with the plant’s surroundings
95
# Dermal tissue
Epidermis layer
| definition, function
Epidermal layer is the outermost layer of the dermal tissue
Secretes a waxy layer called the cuticle (reduces water loss from plant)
96
vascular tissue
| function, main types
Function: Transport of substances around the plant
Found in roots, stem and leaves
Xylem: transports water and mineral salts from roots to the leaves
Phloem: transports sucrose (glucose from PS) around the plant
97
Ground tissue
| definition, features
All of the internal cells of a plant other than the vascular tissue
Is bulk of the plant tissue
Different cell types specialised for food storage, support and photosynthesis.
98
Adaptive radation
Where one species diversifies into many different species as they moe into new areas with differing selection pressures.
99
Natural selection
| Stpes of process
1. Varation in the population
2. Overproduction of species (competition)
3. Selection pressure and selection
4. Reproduction (survive to reproduce)
5. Adaption
100
Marco evolution
change in an species over milliions of years
101
Micro evolution
change in species over some generations and a much shorter period of time
102
Speciation
the formation fo new species
| divergence?
103
allopatric
geographical isolation
104
sympatric
any isolation that is not due o geographical barriers
105
Adaptive radation
The evolutionary variation in a species that evolved from a common ancestor
106
Darwin and Wallace's thoery has two parts...
1. Common decent (ancestor)
2. Natural selection
107
homologous
| organs/structures
have the same basic plan to their sutrcture but show modifictions bevause thy are used in different ways
108
vascular plants
| function, example
Possess a transport system to move substances around
Trees
109
Non-vascular plants
| Function, example, transport used?
Do not possess a transport system
uses passive transport
Moss
110
Stomata
| Found?, structure, features, when they open and close and what they let
Found on the underside of the leaves of plants
The wazy cuticle of leaves does not allow water and gas to get through it
Structure: Each stoma is regulated by guard cells which enable the stomata open and close under different environmental circumstances
Scarce water: stoma will close to reduce water loss through transpiration, not obtain CO2 or remove oxygen wastes
Abundant water: stomata will open to maximise CO2 intake and oxygen outtake, water loss to transpiration
They open in the light and close in the dark to prevent water loss
111
lenticels
| definiton
Pores where gas exchange occurs in woody parts of plants (trunks, branches)
Small dots on wood
Diffusion of gases and water vapour is relatively slow
112
Xylem
| definition, shape on stem, what it trasnports, direction of transport
Type of transport tissue in plants
Transports water and nutrients absorbed from roots up to leaves, where water is a reactant of photosynthesis to occur
Unidirectional transport, carry only up the plant
Shaped like a star/cross inside stem
113
Phloem
| what it transports, to where, what direction, shape on stem
Transport tissue for sugars (form of glucose), result from photosynthesis
From leaves to the rest of the plant
Bidirectional transport, both up and down the plant
Shape of small circles outside stem
114
Composition of xylem
Dead cells, reinforced with lignin, no metabolic support required
115
Composition of phloem
Sieve cells that are living, comparison cells are associated with siese cells metabolic support
116
Function of dermal tissue system
protection, prevention of water loss
117
Function of ground tissue system
Photosynthesis
Food storage
Regeneration
Support
protection
118
Function of vascular tissue system
Transport of water and minerals
Transport of food
119
Tap roots
large central root reaches deep water sources underground, penetrate deeply into the soil
120
Fibrous root
branching roots hold soil in place to prevent soil erosion, close to the soil surface
121
Root hairs
| function
increases surface area for water and mineral absorption
122
# Plants
meristem
region where new cells are produced
123
Root cap
protects tip of growing root
124
Cortex
| Definition
in between the epidermis and the vascular tissue. It acts as a storage area for excess materials, and has air spaces for gas flow.
125
# Plants
Cortex
| Function
To provide anchorage
To provide storage of food
To absorb water and mineral salts
To conduct water and mineral salts to the stem and leaves
126
Role of epidermis in root system
the outermost layer of the root, and specialised epidermal cells absorb water and minerals.
Have a very large surface area that allows water and inorganic mineral salts to be absorbed efficiently.
127
How to substances move into the roots?
Water: osmosis
Mineral ions: diffusion, sometimes faciltiated difusion or active transport if not along the concentration gradient
128
What is the vascular system responsible for?
transport of water and minerals which were absorbed from the soil through the root system
129
Root pressure
Transerve osmotic pressure within cells of root system cause sap to ride through plant stem to leaves
130
# Plants
Capillarity
Movement caused by attraction of molecules of liquid to molecules of solid
131
Cohesion
Water molecules bond to each other
132
Adhesion
Water molecules bind to walls of xylem tubes
133
# Plants
Transpiration
Evaporation from leaves pull water through xylem
134
What type of transport does the phloem use for sugars and nutrients?
Active transport into sinks
Nutrients moved into phloem
135
Shoot system (stem)
| functions
Dermal: Waterproofing, protection, gas exchange
Vascular: composed of the xylem and the phloem within vascular bundles
Ground tissue: fills in around vascular tissue
136
shoot system (leaves)
| function
Absorbs sunlight and carbon dioxide and produce glucose in the process of photosynthesis
137
Structure of leaves
| epidermis
Thin, flat structure of leaves: large SA allows maximum absorption of light energy by chlorophyll inside chloroplasts. Cell are close to surface and can excess light easily
Epidermis is transparent and allows light to penetrate to photosynthetic cells beneath
138
# Plants
Epidermis
| Function and structure
Contains guard cells surrounding stomata
Waxy cuticles reduce water loss from evaporation
Cuticle opens and closes stomata, controls the amount of gas and water vapour exits and enters
139
# Plants
Mesophyll
| layers, structure
Palisade mesophyll: elongated, densely packed with chloroplasts, main photosynthesis cells. Below epidermis, thus exposed to maximum amount of sunlight (photosynthesis)
Spongy mesophyll: located between palisade cells and lower epidermis. Fewer chloroplasts, loosely packed, air spaces around cells (gas exchange of carbon dioxide throughout leaf)
140
Structure of leaves for gas exchange
Large and flat→ maximising surface area available
Contain open air spaces within the leaf → allow gases to move freely through much of a leaf without having to pass through a cell
Secretes waterproof cuticle to prevent evaporation of water
Transparent layer to allow light to penetrate to cells below
141
MRI
radio waves and magnetic field take images of plant structure and creates computer generated 3D images
uses radioactive substances to produce image
142
PET
provides greater detail and functional information about transport and process
uses radioactive substances to produce image
143
X ray computed microtomography
a sample positioned in a x-ray beam is rotated and hundreds of images from different angles are recorded, reconstructed into 3D image
144
movement of co2 in plant
| loacted where in leaf?,
Acquired in stomata, spongy mesophyll
Stomata opens to allow exchange of gases in and out of leaf, CO2 diffuses into spongy mesophyll
145
movement of water in plant
| found where, transported to?
Acquired in roots, root hairs xylem
Diffuses into root hairs, osmosis
High SA of hairs=efficient diffusion of water
Transported up to leaves via transpiration pull, adhesive and cohesion forces
146
movement of sugars
| how plants make it, where they make it, trasnport to where?
Plants use water and CO2 to synthesis sugar sin chloroplasts in mesophyll layer of leaf
Once glucose is made, transported from sources (in form of sucrose), to sinks (areas of growing energy needs)
Transported through phloem (translocation)
147
# Plants
Source
Leaves or bulbs
Where photosythesis ocurs
Sugars trasnported into phloem to heard towards sinks
148
# Plants
Sink
| Areas of?
Areas of active growth
Developing leaves, root tips, flowers
Are areas of low sugar conc and low water pressure
149
Isotopes
Different forms of the same atom
150
Radioistopes
| Why do they radiate?
isotopes which emit radiation (radioactive)
Emit radioactive waves or particles to achieve a stable state
151
# plants
Role of radioistopes in tracking products
They act as tracers and are used to follow the pathways of molecules involved in photosynthesis
Tracked where oxygen molecule was produced from (o2 or co2)
152
# plants
Role of carbon 14 in tracking products
Carbon-14 added to the carbon dioxide supply traced the movement of the glucose produced through the plant
153
Types of animal tissues
| 4
Epthelial, connective, nervous, muscle
154
Epithelial tissue
| location, structure of cells, types of surfaces, function
Covers body surfaces, protects organs, forms glands
Cells are densely packed, in single sheets or layers (depending on location and function)
Does not contain blood vessels, but relies on underlying connective tissue for nutrients
There are two surfaces on epithelial tissue: one surface is exposed to the exterior or to body cavity, the other is exposed to adjacent tissue
E.g. skin, surface of the organs of the digestive system, respiratory system.
Function:
barriers to injury and infection
sometimes absorption or secretion (e.g. epithelial tissue lining the larynx secretes mucus to keep surface moist
155
Connective tissue
| common characterstic, function, 4 types and their functions
Varies greatly in form and function
Common characteristic: extracellular matrix with cells scattered through it
Function: provides support, ensures different parts of body are bound together, protects against damage
Different types of connective tissue vary in their density and arrangement of cells, and ways in which the cells are specialised.
Function: energy storage, insulation, protection, cushioning
E.g. cartilage
Composed of lots of dense collagen fibres
Function: strength, flexibility, cushioning
In nose, rib cage, trachea, ends of long bones
E.g. collagen in the connective tissue in skin
Function: stopping skin from tearing away from bone; elastic fibres restore the skin to its original place and shape.
156
Nervous tissue
| Components, made of, neurons function, dendrities function, structure
Nervous system comprises the brain, spinal cord and peripheral nerves.
Nervous tissue is made of nerve cells (or neurons)
Function of neurons: passing messages between themselves and other cells of the body (communication between all parts of body)
Neurons have multi-branched dendrites and an axon ( long tail extending from cell body, see above)
Function: Dendrites receive messages electrical message passes through cell body transferred along the axon passed onto the neighbouring neuron, muscle or gland.
Structure: branching of the dendrites increases surface area to receive messages; long axon makes passing on of electrical impulse efficient.
157
Muscle tissue
| Structure of cells, types of cells, types of muscle
Contains muscle cells called muscle fibres that are highly specialised for contraction
Three types of muscles cells:
Skeletal
Cardiac
Smooth
All muscle cells are elongated and contain proteins actin and myosin, which interact with each other to cause the cells to lengthen and shorten.
158
Skeletal muscle
| Structure, classes as, features of fibres
Muscles fibres are long and have striations (light and dark areas)
Striations are caused by arrangement of actin and myosin in them
Are attached to bones and their contraction causes movement in organisms
Are classed voluntary (= require conscious thought to function)
159
Cardiac muscle
| Function, classed as, fetures of fibres
Muscle fibres are present in heart
Have striations
Individual cells have connection junction allows for coordinated beating of the heart
Are classed involuntary (= function automatically)
160
Smooth muscle
| Function, features of fibres
Muscle fibres do not have striations
Contractions push substances through specialised organs e.g. gastrointestinal tract, blood vessels, urethra.
Are classed involuntary (= function automatically)
161
Gas exchange in animals
| requirements, 4
large surgace area, moist thin surface, close contact with blood supply and membrane, concentration gradient of gas
162
Why are respitory systems in animals internal
to reduce water loss from respiratory surface
163
Respiratory organ of animals
lungs
164
Alveoli
| structure
Each thin walled alveolus is composed of an air sac connected to external environment, surrounded by tiny thin walled blood vessels called capillaries
165
Alveoli
| features, structure, cell structure, surfaces, surroundings supply
gas exchnage surface
Increased surface area: 300 million alveoli supplied by 280 million capillaries
Alveolus wall consists of flattened cells in single layer, facilitating the efficient diffusion of gases across small distance
The surface of all parts are moist → gases can diffuse in solved form (in liquid), enhancing efficiency
Numerous blood capillaries surrounding the outside of each alveolus ensure close contact with blood
166
Ratio of oxygen in alveoli
| Incoming air, concentration of
Oxygen in incoming alveolar air at concentration >bloodstream
167
Ratio of carbon dioxide in alveoli
| blood stream, concentration of
Carbon dioxide has concentration in bloodstream > in incoming alveolar air
168
Fish gas exchange
| respiratory organ, composition of gases in water, requirements of gills
Gills
Gases are low soluble in water, concetratino is lower than in air
Gills require water flowing over them to ensure maximum oxygen uptake, water flowers out through gills slits
Fish are well supplied with blood capillaries
169
insects gas exchange
| Respitory organ, process of repsiration,
Respiratory organ: tracheal system
Take in air, expel air through structures called spiracles (breathing pores)
Have valves to regulate opening and closing to prevent spiracle surface drying (effect of air)
No gas exchange, no lungs or capillaries
Blood not involved in transport of gases
Small size allows simpler system of gas exchange
170
# insect
Tracheal tubes
| movement of gases through insect, what happens to gases
branching air tubes which carry air directly to cells of body
Air → spiracle pores → tracheal tubes —> smaller tracheoles (large surface area for gas exchange, directly bring air to and from cells)
Gases dissolve in fluid at ends of tracheoles and diffuse directly in or out cells
171
digestion
breaking down of large and complex food particles into much smaller and simpler particles, small enough to be absorbed through the internal walls into the bloodstream
172
mechanical digestion
| steps of process
Mouth: different types of teeth break food into smaller pierce by cutting, tearing, chewing and grinding the food
Stomach: churning motion
Break the food down into smaller parts to increase SAV ratio for enzymes
173
chemical digestion
| defintion, what mlecuels food gets broken down to
process of using digestive enzymes to chemically break down the larger, complex molecules
Complex carbohydrates → glucose
Proteins → amino acids
Lipids → glycerol and fatty acids
Nucleic acids → nucleotides
174
aborption of nurtients, minerals and water
| where occurs, how they are aborbed, where absorbed to
Mainly occurs in jejunum section of the small intestine
Products diffuse or use active transport through villi, which lines intestinal wall
Glucose and amino acids are absorbed into the capillaries
175
Pathway through digestive system
| Mouth, name of enxyme in mouth
Amylase: chemical breakdown of the complex carbohydrates starch into the simplair sugar maltose
Amylase released into mouth with saliva
Mechanical digestion begins
Turns into bolgus
176
Pathway through digestive system
| Oesophagus, structure, entrance, process
Soft walled, muscle-ringed tube to the stomach
Entrance to trachea= a flap of skin (epiglottis)
Muscular contractions move food (with gravity)
Chemical digestion of starch continues during movement
177
order of pathway of digestive track
mouth, oesophagus, stomach, small intestine (deodenum, jejunum, iluem), large intestine, rectum
| liver included
178
Pathway of digestive system
| Stomach, role of muscles, what happens to food, composition of stomach
## Footnote
enzyme used, walls of stomach
Sphincter muscles control energy and exit of substances
Relaxation and contraction of stomach walls (mechanical)
Food combines with gastric juices to form mixture (chyme)
Gastric juices secrete from walls consisting water, HCL and pepsin
pH of stomach 2-3 from acid
Mucus lining of walls protect acid damaging
The enzyme pepsin chemically breaks down long-chained proteins → shorter chained peptides, nucleic acids (DNA or RNA) → nucleotides
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Small intestine
| Entrance, sturcture, three sections,
Chyme enters through small muscular opening
Highly folded tube, 7m long, three sections
Duodenum, jejunum, ileum
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Small intestine, deodenum
| 4 enzymes used for which simple molecules
Entrance to duodenum releases pancreatic juices (digestive enzymes)
Amylase: carbohydrates → glucose
Trypsin: protein → amino acids
Bile (not enzyme): lipids → emulsifies fats into smaller fat droplets, increases SA for lipase enzyme
Lipase: lipids → glycerol and fatty acids
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Small intestine, jejunum
| products of digestion go where, features of walls
absorption into bloodstream occurs
Products of digestion (amino acids, glucose, fatty acids, glycerol) move into blood via diffusion or active transport
Villi: tiny projections along intestinal wall where absorption occurs,
high SA,
moist one cell thick walls
Tiny capillaries wrapped around a lacteal (lymph system)
Glucose & amino acids → blood capillaries
Fatty acids and glycerol → lacteal
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liver
| definition, function
Bloodstream travels to liver, centre of food metabolism
Keeps sugars, glycogen and protein levels balanced
Detoxifies blood
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Large intestine
| materials present, 2 sections, fucntion of each section
Undigested materials (water, salts, dietary fibre)
Colon
Water and some salts absorbed back into bloodstream
Undigested materials become compact, solid
Vitamin A & K produced by bacteria acting on undigested matter, reabsorbed into bloodstream
Rectum
Faeces: remaining waste material
Moved into rectum by peristalsis and then egested from body
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What are the products of digestion used for
CR or energy storage
fatty tissue beneath skin, glycogen in liver and muscles)
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Transport systems in animals
Cardiovascular system
Lymphatic system
through blood mostly
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Lymphatic system
transports excess tissue fluid back to the cardiovascular system, made up of lymph vessels and a fluid called lymph
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Cardiovascular system
made up of the heart and blood vessels
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Composition of blood
| %
55% plasma, 45% blood cells (platelets, red and white cells)
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Red blood cells
no nucleus, biconcave shape, contain haemoglobin which carries oxygen
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White blood cells
nucleus, role in defence of the body
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Platelets
tiny crescent shape, role in blood clotting
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Plasma
pale yellow liquid, carries blood cells and dissolved substances required by cells
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Types of blood vessels
Arteries
Capillaries
Veins
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Arteries
carry blood away from the heart, have thick, elastic walls to cope with pressure of pulsing blood
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veins
| features it contains, movement of blood
carry blood back to the heart, thinner walls
Contain valves to ensure blood moves in one direction
Movement of blood caused by contraction of surrounding muscles
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Capillaries
| composition of walls, gas exchange features
form networks so all cells are supplied with nutrients, gases, wastes removed
Walls are one cell thick, allowing easy exchange between blood and cells
Only one cell at a time can move through walls, increase their exposed surface area for exchange of gases, nutrients and wastes
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Chambers of the heart
| atrium, ventricle, septum, right and left pumping blood from where
Atrium: top
Ventricle: bottom
Septum separates two sides
Left ventricle:
thicker muscular wall
Must pump blood all around body
Right ventricle
Pumping blood to the lungs
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movement of deoxygenated blood in the heart
Deoxygenated blood enters the right atrium, moves to right ventricle, pumped to lungs to obtain oxygen
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movement of oxygenated blood in the heart
Oxygenated blood flows back into left atrium, left ventricle, pumped to the rest of the body before returning to right atrium
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open circulatory system
| what happens when heart muscles moves in a certain way
contains heart that contracts and pushes haemolymph through vessels to bathe the organs
When heart muscle relaxes, heart expands, fluid drawn back into heart
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Haemolymph
Fluid in the open circulatory system
Transports nurtrients and wastes
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Closed circualtory system
contains blood that is totally enclosed in vessels, with heart providing driving force to push the blood around the body
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pathway of blood from heart to heart
Arteries → arterioles → capillaries → venules → veins → heart
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oxygen composition in blood to organs
Lost everywhere but lungs
Gains carbon dioxide everywhere but lungs
Lungs gains oxygen and loses carbon dioxide
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Nutrients and waste composition in blood to organs
Lost nutrients everywhere but small intestine
gains waste everywhere
Blood gains productions of digestion in small intestine (increased nutrients)
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Urea composition in blood to organs
Urea decreases at kindneys
Everywhere else is stable urea
concentration of water and salts will have changed according to the needs of the body
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Ecosystem
community together with its environment (biotic, abiotic)
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Environment
made up of all the nonliving factors (abiotic)
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Population
groups of organisms of the same species living in the same area at a particular time
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Community
groups of different populations in an area
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Ecosystem
a community of organisms living in proximity to one another
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Abundance
the number of individuals per unit area
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Distribution
the spread of a population over space
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Selection pressure
A factor that affects the likelihood of particular species or variation within a species surviving to reproduce.
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Selective advantage
an increased relative ability to survive or reproduce under a given selection pressure
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Natural selection
process whereby species which have traits that enable them to adapt in an environment survive and reproduce, pass on their genes to the next generation
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sampling techniques for abundance
quadrats, capture-recapture
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sampling techniques for distribution
transects, drones
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When were cane toads introduced and why
Introduced to australia (1935) to control greyback cane beetle in sugar plantations
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Positive and negative selection pressures for cane toads
No natural predators, Increased food source for native fauna, Became fast moving and directional due to spatial sorting, Larger size and longer leg
negative -->Development of arthritis in older, larger toads
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When were prickly pears introduced and why
20th centuary, used for food for the cochineal insect and used as a hedge plant
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positive and negative selection pressures of the prickly pear
+ --> Good in arid climates
- --> Cactoblastis moth introduced as biological control
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adaption
characteristic that an organism has inherited and that makes it better suited to survive in its environment
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Types of adaptions
| 3
Structural
Physiological
Behavioural
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Structural adaptions
| plant and animal examples
Refers to how an organism is built or structures so that it can survive in its natural environment
It is the physical features on both the inside and outside of an organism
e.g. webbed feet on platypus enables fast swimming,
E.g. webbed feet on platypus enables fast swimming,
thin pointed leaves on spinifex grass reduced water loss
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Physiological adaption
| plant and animal examples
Those that relates to how an organism functions and increase its chances of survival in its natural environment
Involve variations in the metabolism or physiology of organisms at a cellular, tissue, organ or system level giving them specific advantages
E.g. intertidal marsh crab has skills and kidneys that function to concentrate next group excess salt
Plant cells found in the growing tips of stems are sensitive to the hormone auxin, which causes them to grow towards light
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Behavioural adaptions
| plant and animal examples
Refers to those activities performed by an organism in response to stimulus that improves its chances of survival
E.g. Venus flytrap is a plant adapted to live in nitrogen-poor soils. It is able to act rapidly when a small insect alights on it, trap it as a source of food.
Brown snakes are found in hot, dry areas of Australia, seeks shelter in shade during day and becomes active in other parts of the day (or night) when cooler.
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Darwins 2 observations and theories
1. Magpies and crows are similar to jackdraws in England, but different species
1. Organisms can evlve to be siilar (convergent), have similar varaitions
2. Trees had long, narrow leaves hung vertically, did not shed periodically like in England, bark fell in hot months
2. Features made ecualypts suited to hot dry environment, suirvive in harsh conditions
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What did Darwin saw abou the Galapagos finches?
| date he went
Vited in 1835, finches were similar on differnt islands, shwoed disinct varations in break size and structure depending on local food source
Finches arrived in past and changed oertime to better suit their environment
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Species diversity
a measure of the diversity of different species in an ecological community
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Ecosystem diveristy
he variety of different habitats, communities and ecological processes
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genetic diversity
| importance
refers to the total number of genetic characteristics in the genetic makeup of a species
needed for survivability with variations and abilities that are advantaged
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Speciation
| caused by, features of cause
formation of new species caused by small micrevolutionary changes --> isolation, different selection pressures
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Homologous structures
| example
having the same or similar structure, corresponding in origin but not necessarily in function
e.g. pendactyl limb
235
Analogous structure
having different structures but the same function
236
Divergent evolution
the process in which groups from the same common ancestors evolve and accumulate differences, resulting in the formation of new species
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Convergent evolution
the process by which organisms that do not have a recent common ancestor develop similar features in response to similar selection pressures in their environments
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gradualism
Suggests that populations slowly diverge by accumulating changes in characteristics due to different selection pressures
239
punctuated equilibrium
Proposes that evolution occurs in short bursts of rapid change followed by long periods of stability within populations
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Morphological edvidence for evolution
comparative autnoomy (structural siialrities, vesitgal structues, embyology)
Fossil records (relative dating, absolute dating)
Biogeography
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Molecular/biochemicla evdeince for evolution
amino acid sequecing, DNA hybirdisation, DNA sequencing
242
Competition
When two or more organisms use one or more resources in common
Usually for a resource within the environment that is limited in supply but valuable for survival
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Predation
A predator prey relationship is a type of feeding relationship where the predator obtains its food by killing and eating another animal
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Symbiosis
| 3 types
A predator prey relationship is a type of feeding relationship where the predator obtains its food by killing and eating another animal
Mutualism, commensalism, parasitism
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Mutualism
both species in the relationship benefit from the association (+/+)
246
Commensalism
one species benefits and the other suffers is unaffected (+/0)
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Parasitism
one species benefits and the other suffers non-lethal damage (+/-)
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Allelopathy:
plants that use chemicals to stop other plants from growing
249
niche
| prinicble behind species using it
all the resources that a species uses, including biotic and abiotic factors
Not many species can occupy the same niche → competitive exclusion principle
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Consequences for predation
| Trend of prey and predator numbers
Predators affect the distribution and abundance of their prey
Abundance of predator and prey fluctuate
Predator numbers copy prey numbers
As prey are consumed, their numbers drop, leading to food shortages for predators, whose number also declines
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Consequences of competition
Effects reproduction and survival rates
Population fluctuations can be linked to competing species and their resource
Some species may be more successful competitors than others
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Consequcens of symbiosis
Increase evolutionary diversification → biodiversity
Development of new species from the integration of genetic material with each other
Allows increase in biodiversity and resilient ecosystems
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Consequences of disease
Simple change in environmental factor causes stress on organism, comprise its barriers to invasion by pathogen
Emerging diseases alternance balance of food webs dramatically
Affected species will decline → affects numbers of predators and prey
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Theories behid Megafaunal exitinction
| climate and humans
1. Continent died out due to ice age
Climate got hotter, dryer fires broke out, dier vegetation caught fire easily
Rainfroests were contracting die to drier climate
Animals and plants died with no moisture
2.Aboriginal people were successful predators
They used fire to blackburn, burning vegetation
Hunted large animals
