module 2 organisation of living things Flashcards
(94 cards)
1
Q
what is a unicellular organism
A
contain only one cell which can be either prokaryotic or eukaryotic
2
Q
main characteristics of unicellular organisms
A
- always directly exposed to environment
- must remain microscopic to ensure the large SA:V ratio, this enables substances (nutrients and gases) to pass through efficiently through the cell membrane; critical for survival
3
Q
example of a unicellular organism
A
bacteria, amoeba
4
Q
what is a colonial organism
A
colonial organisms are made up of a group of identical single celled organisms collectively; called a colony
5
Q
main characteristics of colonial organisms
A
- all cells are capable of carrying out functions necessary for life (can be classified as single celled)
- some colonial organisms contain cells that have specialised functions: contributes to more efficient functioning of all members in the colony
6
Q
examples of colonial organisms
A
coral, jellyfish, volvox
7
Q
what is a multicellular organism
A
made up of many different types of cells. Similar cells re grouped together to perform a specialised function that combine for efficient functioning of the organism
8
Q
main characteristics of multicellular organisms part 1
A
- specialised cells in multicellular organisms cannot live independently, unlike those of unicellular or colonial
- they are larger in size and the nSA:V ratio is small
- Organisms this large cannot rely on passive transport eg osmosis and diffusion to obtain nutrients, therefore the specialised cells perform such functions
- arranged into groups
9
Q
example of multicellular organism
A
humans
10
Q
main characteristics of multicellular organisms part 2
A
- the division of labour (b/w specialised cells) increases the effectiveness of carrying out their functions: this efficiency allows the organisms to be larger and therefore exploit environments that allow them to be successful in survival and reproduction
- stem cells (young cells) are similar in structure to one another and then divide and grow
- as these stem cells mature they differentiate (specialised) so they can carry out different roles eg fight infection
11
Q
passive transport
A
the movement across a cell membrane WITHOUT the use of energy to move by going DOWN/WITH the concentration gradient
- (from high to low concentration)
12
Q
active transport
A
the movement across a cell membrane WITH the use of energy (ATP) to move by going AGAINST the concentration gradient
- (from low to high concentration)
12
Q
3 domains of life
A
archaea, bacteria and eukaryotes
13
Q
organisation of life multicellular organisms order/heirarchy with example
A
organelle (mitochondria) → cells (muscle cells) → tissues (cardiac muscle tissues) → organs (heart) → systems (circulatory system) → organism (human)
14
Q
what is the hierarchical structural organization on multicellular organisms and why is it organised this way?
A
- it is the ways cells are organised in multicellular organisms that forms an organisms
- each level has a specialized function
- it is organized like this because each division has specialized functions and this hierarchy allows for reactions to take place eg diffusion
- also the SA:V ratio would be too low for some organisms and the hierarchy allows jobs to be done
15
Q
main characteristics of skin
A
- largest organ in the body and its role is too be a protective barrier against external elements
- cell death is is used to benefit the younger tissue as the outer layer of skin (epidermis) asn it acts as a barrier and protects living cells underneath
16
Q
advantages of being multicellular
A
- more to consume
- protected insides
- live longer
- the ability to specialize cell types for various functions
- larger
17
Q
disadvantages of being multicellular
A
- increased energy requirements
- more complex waste processing
- longer development times
18
Q
what is differentiation and why
A
whereby stem cells during embryonic phase are programmed (by the on of genes) to turn into a specific type of cell
- cells differentiate to IMPROVE EFFICIENCY in various ways eg growth, movement etc
19
Q
stem cells
A
found in bone marrow and embryos and are undifferentiated cells
- divide by mitosis
20
Q
example of differentiated cells
A
the cells involved in the u[ptake of chemicals have a shape that maximises teir SA:V ratio eg flttatned cells of the tissues lining the air sacs in lungs
21
Q
structural features and their function (how they relate): small intestine
A
- thin, long, elongated shape
- a function of absorbing nutrients and water by diffusion (1 cell thick lining)
- this structure allows the function to be more efficient eg faster diffusion
22
Q
structural features and their function (how they relate): skeletal muscle
A
- fibres have cylindrical shape and blunt ends
- function of being specialised for contraction and responsible for movement, pressure maintaining , generating body heat
- its structure relates to its function as it enables them to efficiently and powerfully contract, allowing for movement and other essential bodily functions
23
Q
structural features and their function (how they relate): motor neurone
A
- cell body has a single axon and multiple dendrites with large long projections: long
- function of receiving signals from other neurons and transmitting commands to brain
- voluntary and involuntary movements
- structure ensures for efficient function; long body enables signals to be received from others etc
24
structural features and their function (how they relate): sperm cell
- head contains DNA, midpiece for energy production and tail for movement
- function to fertilize egg cell and provide half the genetic material
- the long tail enables the sperm cell to travel fast to fertilise the egg
25
structural features and their function (how they relate): red blood cells
- biconcave shape (disc) and no nucleus , red pigment, small
- function to transport oxygen from the lungs to the body's tissues
- the biconcave shape increases the SA for efficient diffusion and no nucleus allows it to get through capillaries
26
structural features and their function (how they relate): xylem
- long cells with thickened walls, hollow and impermeable
- function to transport water and minerals from root
- structures helps function as it allows it to stand upright
27
structural features and their function (how they relate): guard cells
- inner side is thicker than outer side
-function of regulating transpiration through stomata
- the structure facilitates function as it helps it bend outward when turgid (opens stomata)
28
structural features and their function (how they relate): palisade cells
- function to photosynthesis
- elongated cylindrical columnar shaped cells
- tightly arranged to maximise light absorption and to increase SA for efficient diffusion
29
structure and components of systems: circulatory
- transport oxygen, nutrients and hormones to the body's cells and to remove waste products
- components include heart, blood vessels, blood and arteries
30
structural features and their function (how they relate): digestive
to break down food into smaller molecules that the body can absorb
- components include moth, stomach, small intestine, anus etc
31
structural features and their function (how they relate):excretory
- removes excess waste products to remain homeostasis
- components include kidney, bladder etc
32
structural features and their function (how they relate): respiratory
- moves fresh air into body while removing waste gases (co2)
- consists of lungs, diaphragm, bronchi etc
33
structural features and their function (how they relate): endocrine
- release hormones into the bloodstream
- consists of pituitary, thyroid
34
structural features and their function (how they relate): lymphatic
- protecting your body against invaders eg infections
- lymph nodes and vessels
35
structural features and their function (how they relate): skeletal
- provide support, produce blood cells and release minerals
- consists of bones, cartilage, ligaments and tendons
36
structural features and their function (how they relate): integumentary
- regulate body temperature, sensation and waste removal
- consists of skin, hair, nails, glands
37
tissue
a group of specialized cells working together
38
structural features and their function (how they relate): epithelial tissue
structure of densely packed cells in single sheets/layers
- function of covering body surfaces to protect organs eg larynx
- structure allows diffusion to occur selectively dependent on the layers of the cell
39
structural features and their function (how they relate):connective tissue
- structure of protein fibres (collagen) and elastic
- function of providing support and ensuring parts of the body are bound eg cartilage
- structure is related to function in the way the cells are arranged
(same direction parallel to tendon) to provide strength whilst being flexible)
40
structural features and their function (how they relate): muscle tissue
- structure of fibres specialised for contraction
- function of pumping blood and supporting ,movement
- tissue structure enables the function
41
salivary glands function
make saliva which moistens food for swallowing
42
mouth function
- eating, speaking breaking down food
43
oesophagus
transport food from mouth to stomach
44
liver function
breaks down nutrients to make them non-toxic
45
gall bladder function
store and breathe bile (which breaks down food)
46
stomach function
temporary storage, chemical and mechanival digestion
47
pancres function
produce enzymes that break down food
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small intestine function
break down and abosrb nutrients
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large intestine function
absorb water and produce bitamins
50
rectum function
hold waste
51
anus function
release waste
52
types of digestion
physical and chemical
53
physical digestion
begins in the mouth with the action of your teeth and tongue and continues in the stomach where the stomach contracts and relaxes to grind the food
- also bile physically breaks down large fat globs into small droplets
54
chemical digestion
- more complicated and begins in mouth but special protein based chemical known as enzymes break the large complex molecules into small ones
55
absorption
absorption is the process where the small intestine absorbs nutrients from digested food into the bloodstream
56
elimination
removing undigested food and waste products from the body through the anus as feces
57
role of the respiratory system
to take oxygen from the air amd to expel CO2, known as gas exchange which is needed for aerobic respiration and overall function. All cells need oxygen to function, with diffusion with the concentration gradient being a key process in this system
58
four features that all gaseous exchange surfaces have in common
- large SA (increasing opportunity for diffusion)
- thin walls (more efficient diffusion)
- moist surface (easier for dissolved water to diffuse)
- rich supply of blood (maintaining concentration gradient)
59
respiratory surface: mammal (human)
- alveoli in lungs
- alveoli lined with thin moisture
- millions of tiny alveoli increases SA
- oxygen diffuses into capillaries and blood transports the oxygen
60
respiratory surface: insect
- tracheoles is the respiratory surface
- has moist walls for diffusion
- extensive trachea network branching throughout body to increase SA
- air enters through spiracles and o2 diffuses directly to tissue via tracholes
61
respiratory surface: fish
- gills is the respiratoy surfaces
- kept moist by wet environment
- thin filaments with folds that inmcrease SA
- water flows over gills and oxygen diffuses from water into blood gill capillaries
62
respiratory surface: frog
skin and lungs as respiratory surface
-0 mucus and moist environments keep it moist
- lungs have folds and lots of capillaries to increase SA
- diffusion through skin into blood, also by lungs oxygen is supplied
63
open circulatory system
An open circulatory system is a circulatory system in which the blood, also known as hemolymph, is not confined to blood vessels, but instead flows freely through a body cavity called the hemocoel
- eg prawns, molluscs
64
closed circulatory system
A closed circulatory system is a circulatory system where blood is always contained within vessels.
- humans, vertebrates
65
open circulatory system characteristics
heart pumps fluid through short vessels and into a large cavity called the haemocoel
- bathed with blood
- vessels acts as drains to the heart
- inefficient
- oxygen is carried in the fluid haemolymph
66
closed circulatory system characteristics
- blood is fully enclosed within blood vessels
- capillaries diffuse substances in and out of the blood
- blood returns to heart by vessels
- is regulated
- oxygen is carried through the blood stream and then diffuses into capillaries with co2 being excreted
- efficient (overcomes low sa:v ratio)
67
arteries
carry blood away from the heart
- have thick walls made of elastic fibres and muscle
- arterioles are small and have less elastic fibre to allow them to contract and reduce blood flow to control blood loss in injuries
68
veins
carry blood back to the heart
- blood from the capillaries drains into small veins called venules
- blood pressure is low, so to make it easier for blood to get through veins are bigger than arteries and have thinner walls and a larger bore
- also have valves, which stop the blood from going backwards and squeezing it in the right direction
69
capillaries
the tiniest blood vessels
they are narrow to blood cells can squeeze along then, slowing it down and helping the exchange of materials
- reduces blood pressure
- blood leaving the capillaries has much less energy than blood entering one
70
comparing arteries and veins
A: carry blood away from heart , carry blood rich in oxygen mostly, impermeable, blood under high pressure due to elasticity of fibres and heart beat, discernable pulse, thick middle layer, no valves, deep seated
V: carry blood to the heart, carry deoxygenated blood to heart, selectively permeable, low pressure so its easier to get through walls, thin layer and large bore for easy flow, yes valves, superficial veins
71
the composition of blood: red blood cells
- biconcave shape
- small with no nucleus
- function to transport oxygen throughout the blood stream
72
the composition of blood: white blood cells
- large nucleus
- bigger than red blood cells
- function to defend the body against infection and disease by destroying infectious agents
- produces antibodies
73
the composition of blood: platelets
- small fragments found in plasma
- no nucleus
- helps forms clots to stop bleeding
74
the composition of blood: plasma
- mainly water with other minerals and nutrients eg glucose
- function of taking in nutrients, hormones and proteins to parts of the body
75
76
what do heterotrophs need to survive
- nutrients (food): carbohydrates, poteins, lipids, vitamins and minerals
- water
- oxygen
- removal of co2
- removal of nitrogenous water
- reproduce
77
leaves
function of photosynthesis: converts sunlight into water, co2 and glucose
78
roots
function to anchor plant, absorbs water and nutrients
79
stem
fucntion of support, transport and storage
80
flowers
function of reproduction
81
autotrophs and heterotrophs
Autotrophs are organisms that can produce their own food, while heterotrophs rely on other organisms for sustenance
82
cuticle
the up most layer of the leaf and function of being a protective layer that prevents water loss
83
epidermis
under cuticle and 2nd layer, function of being a boundary b/w external environment
- lower and upper
84
stomates
opening on underside of leaves with guard cells on each side, function of facilitating gas exchange
85
palisade mesophyll
cells under upper epidermis and function of capturing sunlight and making it in its chemical form
86
spongy mesophyll
within leaf and allows co2 to diffuse for gas exchange
87
xylem
towards the middle and function of transporting h20 and nutrients
- non living with thick walls
- direction of flow is up only and passive transport
- transports water and dissolved minerals and is positioned in the middle of the vascular bundle
(star shape in root)
88
phloem
on the outside of xylem and function of transporting sugars
- living and thin walls
- direction of flow is up or down and transports sugar, strach and nutrients
- active and passive transport and is located on the outer edge of the vascular bundle (b/w the star in root)
89
transpiration
the movement of water and minerals from the roots via the xylem to the leaves and out of the leaves via the stomata due to evaporation
90
theory for movement of materials in xylem
the cohesion-adhesion-transpiration mechanism is currently the theory that accounts for the ascent of xylem sap
- sap is mainly pulled by transpiration
- cohesion is the sticking together of water molecules so that they form a continuous stream of molecules
- adhesion is the process of water molecules sticking to other surfaces eg the sides
- transpiration is the pulling of water from root to leaf by transpiration pull
- the thinner the tube the further the water will go up
- one way constant pull due to evaporation via transpiration
CAT THEORY
91
theory for movement of materials in pholem
pressure flow mechanism (SOURCE TO SINK)
- movement both ways (because sugar is needed for cellular respiration)
STEPS: 1. sugar is loaded into the phloem tube from the sugar source eg leaf photosynthesis (by active transport) *AGAINST CONCENTRATION GRADIENT
2. water enters by osmosis due to high solute concentration in the phloem tube (water pressure raised at end of tube
3. at the sugar sink where sugar is stored) sugar leaves the phloem tube which water follows leaving by osmosis thus dropping water pressure
4. the building of pressure at the source end and reduction of pressure at sink end causes the water to flow from source to sink
5. water is dissolved and seive tubes b/w phloem cells allow the movement of phloem sap to continue unimpeded
92
translocation
movement of sugars in phloem (source to sink theory)
93
radioactive carbon tracing for phloem
Radioactive carbon tracing, specifically using Carbon-11 (11C) or Carbon-14 (14C), is a valuable tool for studying phloem transport in plants. These isotopes are incorporated into plant tissues during photosynthesis and can be traced to understand the movement of sugars and other organic compounds throughout the plant.
