Osemoregulation

 

Locomotion

A) Principle :

bone + joint + muscle

Bone : Provide surface for muscle attachment

Bone and Joint : Forming lever system

Muscle : contraction provide effort to the lever system , Antagonistic pair of skeleton attached to bone to provide movements in opposite direction

B) Sliding-filament Hypothesis :

1. At arrival of action potential, it propagates along the sarcolemma.
2. Formation of cross-bridge between myosin and action
3. Actin slide toward myosin cause shorten of sarcomere, then cause shortening of muscle fibre
4. ATP is consumed and provided by mitochondria

 

 

 

Comparison the means of support between aqueous vertebrates and terrstrial vertebrates

 

Aquatic vertebrates	Terrestrial vertebrates
-Body weigh supported by water	-Body weigh support by limb with strong muscle
-No limb and strong muscle necessary	-Limb and strong muscle necessary
-Less energy required for support	-More energy required for support
-Appendages in forms of fin rays	-Appendages in form of limb
-pelvic girdle does not connected to vertebral column	-pelvic girdle connected to vertebral column

Synovial Joint

 

 

Hormone stimulating Growth

A) Stomatic Growth :

Normal Growth :

1) Growth Horone :

• Increase growth and development of bone of limb
• Protein synthesis

2) Thyroxine :

• Skeleton growth
• Increase metabolic rate

Secondary Growth :

1) Testosterone :

• Muscle development
• Shoulder enlargment
• Larynx enlargment

2) Oestrogen :

• Breast development
• Broading of pelvic girdle

B) Reproductive Growth :

Functions of Hormone

 

A) Adrenaline :

1. Increase cardiac output
2. Vasoconstriction of blood vessel supplying gut,skin,reproduction organ, Vasodilution of blood vessel supplying skeletal muscle
3. Relaxation of smooth muscle of gut  and dilution of brochiole -> Enlargment of thorax to increase ventilation volume and oxygen uptake rate
4. Promote break down of glycogen to glucose by releasing ACTH
5. Increase sensitity of nerve system
6. Save heat by vasoconstriction of skin arteries

B) Noradrenaline :

1. Increase cardiac output
2. Vasoconstriction of all arteriole

C) Thyroxine :

1. Regulate growth and development
2. Increase metabolic rate
3. Produce heat
4. Increase cardiac output
5. Decrease blood glucose by increaseing metabolism

Pituitary gland

Anterior pituitary:

1. FSH, follicle stimulating hormone
2. LH , lutenizing hormone
3. GH , growth hormone
4. TSH
5. ACTH

Posterior pituitary :

1. ADH, antidiuretic hormone
2. oxytocin

Hypothalmus

A) Basic concept :

Stimulation -> detection -> regulation -> effector -> correction

* negative feedback mechanism

Stimulate :

a) Directly (hypothalamus act as both detecter and regulator)

1. Regulation of core temperature
2. Regulation of plasmic osmolarity
3. Regulation of hormone level in blood

b) Indirectly (Detected by other organ and regulated by hypothalamus)

- Sensory nerve impulse :

1. Skin temperature
2. Sensors in nipples

- Nerve impulses from brain

1. Smell
2. Taste

Regulation :

a) Sending nerve impulses to effector :

1. Skeletal muscle to shrivering
2. Adrenal gland

b) Secreting hormone :

1. ADH -> kidney tubules
2. oxytocin -> milk gland and uterus
3. FSH -> ovary

c) Secreting trophic hormone :

1. TSH ----(thyroxid gland)----> thyroxine
2. releasing factor -> anterior pituitary -> ACTH -> adrenal cortex
3. LH
4. FSH

 

B) Major function :

1. Moniter hormone and other substance level in blood
2. Regulate body activites, e.G:hunger, sleep
3. It preduce ADH and oxytocin which then stored in pituitary gland
4. It control the release of hormone from anterier pituitary by secreting neither inhibiting factor or releasing factor.

The Different and Similarity between Nervous System and Hormonal System

 

Similarity

1. Cells in both System are capable of transmitting message
2. Both system are important to coordinate

Difference

Nervous System	Hormonal System
-Short term effect	-Long term effect
-Faster response	-Slower response
-Localized effect	-Wildspread effect
-Affect muscle and gland	-Affect metabolism and long term process
-electrochemical in nature	-chemical in nature

Transport in Mammal

 

A) Heart

1) Mechanism of heart beating :

• Heart beat simultancously and rhythmic to pump blood along blood vascular system

 

2) Nerves control of heartbeat :

3) Cardiac cycle :

 

* Blood flow from high pressure to low pressure

B) Blood Vessel :

Structural Adaptation of Blood Vessel :

1) Arteries :

1. Thick Wall : Withstrand high blood pressure
2. Thick elastic fibres : Recoil after the dilution, push blood further away
3. Nerve supply : regulate the diameter of the arteries

2) Vein :

1. Valve : prevent backflow
2. Large lumen : reduce resistance
3. Attached by skeletal muscle : force blood forward

3) Capillary :

1. Protein channel : allow small molecule pass through
2. Thin wall : rapid diffusion
3. Small diameter : slow blood flow allow longer time to exchange
4. Network of capillary : increase surface area
5. Close to tissue : shorten the distance

 

C) Blood :

1) Oxygen dissociation curve :

At high oxygen tension, e.g: lung surface, % of saturated haemoglobin is near 95, this facilitates the uptake of O2 as oxyhaemoglobin. At tissue, a slight decrease of oxygen tension result in rapid drop in dissocation of oxyhaemoglobin , which oxygen will diffuse out rapidly.

 

2) Bohr effect :

At high CO2 tension, the haemoglobin is less efficient in taking up oxygen it can cause by increase [CO2], decrease pH and increase temperature   (CO2 diffuse forms carbonic acid, carbonic acid dissoicate to liberate H+, H+ combine with haemoglobin to displace O2 )

3) Adaptation of organism :

For organism living in low oxygen tension atmosphere :

It allows organism to attend high % of saturated haemoglobin at lower atmosphere oxygen tension.

 

For high metabolic organism :

It allows organism to release more oxygen at tissue

 

D) Lymph :

1) Mechanism of forming lymph :

1. High blood pressure at the arteries end of capillary, due to (1)pumping action of heart and (2)high pressure of artery
2. The high hydrostatic pressure exceeds the osmotic pressure in blood, which force all constituents of blood plasma except large protein out to the intercellular space through capillaries wall by filtration forming tissue fluid.
3. Most of the tissue fluid is drawn back into capillary by osmosis due to high water potential of the tissue fluid at the intercellular space the rest of them is forced into the lymphatic vessel forming lymph.

2) Significant of lymph :

1. Forming linkage between tissue fluid and blood vascular system
2. Transport absorbed fat from lacteals
3. lymph node (a) produce lymphocytes which produce antibody to neutrolize the effect of antigen, thus ,it is a part of immune system. (b) phagocyte engulf bacteria and foreign particle in lymph

Nerve System

 

A) Mechanism :

1) Resting potential :

1. Na+/K+ pump at membrane pump 3Na+ out and 2K+ in the membrane using energy
2. Membrane is more permeable to K+ than Na+ at rest. The tendency of K+ diffuse out is more than Na+ diffuse in along the concentration gradient , forming inside negative and outside positive

2) Action potential :

Arrival of action potential , which higher than threshold value

↓

Membrane is more permeable to Na+

↓

Rapid influx of Na+ across the membrane, and it is even enhanced, and it is even enhanced the permeability

↓

Depolarization begin (reversal of charge), action potential begin

↓

Reversal of charge cause decrease in permeability of Na+ and increase in permeability of K+

↓

K+ ion flow out cause Repolarization

↓

K+/Na+ pump pump K+ in and Na+ out restore resting potential

3) Transmittion between neurone :

• Upon arrival of action potential, the neutrotransmitter is released in vesicle, it diffuse across the synaptic cleft for relaying information to the opposite side.
• The post-synaptic membrane possesses receptors to specifically combine with the neutrotransmitter, leading to increase of permeability of Na+, thus increase in membrane potential. As more neutrotransmitter substance arrive until sufficient depolarization occurs and exceeds the threshold value, action potential is generated.

4) Rate of Transmittion :

1. Temperature
2. Diameter
3. Myelinated

• Unmyelinated nerve transmit nerve signal as countinous spread ,which is smooth progressive movement
• In myelined nerve , the myelin sheat is resistant, the signal can only occur at node of Ranvier. Depolarization occur from one node to another node, which spread as discountinous spread.

B) Brain :

1) Spinal cord :

1. Sensory neurone relay sensory impulses from limb receptor via spinal nerve to brain.
2. Motor impulses and interneurons relay moter impulses from brain via spinal nerve to limb muscle.
3. Reflex action

2) Medulla :

1. Maintain homostatic in body

3) Cerebellum :

1. Muscle tone
2. Sensitivity of tendon
3. Sensitivity of Organs of balance in ears

4) Cerebrum :

1. Control of voluntary action (initate of action)
2. Site of sensation (final station)
3. Association
4. Learning and memory

C) ANS :

Comparsion between Sympathetic Nervous System and Parasymthetic Nervous System :

Sympathetic Nerve System	Parasympathetic Nerve System
-Close to spinal cord	-Close to effectors
-Short preganglionic fibres, Long postganglionic fibres	-Long preganglionic fibres, Short postganglionic fibres
-Many postganglionic fibres	-Many preganglionic fibres
-Wide area effect	-Restricted area
-Widespread effect	-localized effect
-Excitatory homeostatic effect	-Inhibitory homeostatic effect
-Mobilizing energy for emergency use	-Save energy and restore to rest state
-Dominating during stressful	-Dominating during rest
-Noradrenaline	-Acetylcholine

 

Mechanism of ventilation

Adaptation of Air Sacs for Gaseous Exchange

 

Adaptation for all transport :

1) large number of alveoli -> vary large surface area

2) thin layer of epidthellium -> short distance for diffusion

Adaptation for diffusion :

3) moist, covered by mucus -> dissolve and diffuse rapidly

4) covered by network of capillary -> oxygen can delivered to body rapidly , CO2 can delivered out the body rapidly,  create steeply concentration gradient to fasten diffusion

5) low blood pressure in nearby capillary -> stay longer time for gaseous exchange

Structural Adaptation of Leaves for Photosynthesis and Gaseous Exchange

 

-photosynthesis require light, CO2 and H20 as substrate

1) Thin flat shape :

light :

• Maximized the area explosed to light
• Minimized the distance of light to mesophyll cell

CO2 :

• Minimized the distance of CO2 to mesophyll cell

2) Epidermis :

light :

• thin layer
• transpiration, allow light to penetrate

water :

• covered by cuticle , reduce water loss

3) Palisade mesophyll cell :

light :

• closely packed
• lots of chloroplast

4) Spongy mesophyll cell :

CO2 :

• lots of air space

5) Stomata :

CO2 :

• mechanism controling gaseous exchange and water loss

Water :

• mechanism controling gaseous exchange and water loss
• located mainly at lower site

6) Vein :

• act as skeleton
• remove photosynthetic product

 

* think the structure of a leaf first

Phytohormone

Regulation of plant growth and development by phytohormone

A) Germination :

-Gibberellin :

1. Break seed dormancy

B) Growth :

-Auxin :

1. Promote cell elongation in region of elongation
2. Promote cell division in vascular cambrium
3. Regulate phototropism and geotropism

-gibberellin :

1. Promote stem elongation

C) Fruit development :

-Auxin :

1. Stimulate fruit development even without fertilization

-Gibberellin :

1. Stimulate fruit development even without fertilization

Double Fertilization

 

 

Germination

1. Uptake of water by imbibition
2. Synthesis of Gibberellins
3. Synthesis of hydrolytic enzymes
4. Break down of insoluble food reserves in endosperm into simple soluble substance
5. The simple soluble substance translocated to growing embyro for utilization

 

Comparison between Sexual Reproduction and Asexual Reproduction

 

Asexual Reproduction	Sexual Reporduction
-one parent only	-one / two parent(s)
-no gamete	-have gamete
-no meiosis	-have meiosis
-genetically indentical	-genetically different
-large offspring is produced	-smaller offspring is produced
-fast	-slow
-occur commonly in lower organism	-occur commonly in plant and animal

Requirment for Sexual Reproduction

 

1. Individual reach sexual maturity at the same time, so that both of them can produce gametes.
2. Meiosis in life cycleto produce haploid gametes, so that in fertilization, diploid can be restored.
3. Transfer of gamete together for fertilization.
4. Availability of male and female that are compatible at breeding state.

Seed Dispersal and Seed Dormancy

 

Seed Dispersal :

A) Defination :

• Spread the seeds of plant away from parent plant
• by natural agent, e.g : wind ,water,insect,fruit

B) importance :

1. Reduce intraspecific competition due to overcrowding
2. Allow greater distribution of species to escape from species-species pest
3. Reduce chance of backcrossing will cause inbreeding

Seed Dormancy :

A) Defination :

• State of seed which is very low metabolic rate just to maintain alive , even when favourable condition

B) importance :

1. Length of seed dormancy varies between individual, prevent intraspecific
2. Allow more time for seed dispersal
3. Competition withstand unfavourable condition, e.g: lack of food
4. Allow storage of seeds for human food

Structural adaptation of halophytic plant for water

A) Reduce water loss :

• Leaf with thick waxy cuticle
• Sunken stomata
• Erect leaf to reduce heat adsorption
• Epidermal hair

B) Storage :

• Succulent leaves
• Succulent stems
• Succulent roots

C) Remove excess salt :

• Salt gland
• Active pump salt out root xylem
• Keep low molecular mass of carbohydrate to lower the water potential

Structural adaptation of xeromorphic plant for water

A) Reduce water loss : (Leaves)

Stomata :

• Reduction of stomata
• Sunken stomata
• Closure of stomata during day and open at night

Surface :

• Thick waxy cuticle
• Presense of hair

Leaves shape :

• rolling leaves
• needle leaves

B) Storage :

• Succulent of leaves
• Succulent of stems
• Succulent of roots

C) Increase water uptake : (Root)

• Deep and extensive root system
• shallow root system

Environment factors that affect salt absorbtion in plant

A) Temperature :

• increase temperature will increase rate of salf absorption. Over optinum temperature will have inhibitory effect by denature of enzyme

B) pH :

• pH affect the ionization of the electrolytes

C) Light :

• light affect opening of stomata, which than affect the rate of transpiration.
• light effect the rate of photosynthesis, thus affect the rate of active transport.

D) Oxygen tension :

• oxyten tension affect the rate of respiration, thus affect the availability of ATP for active transport.

Adaptation of absorption of Water and Mineral Salt for root in plant

 

1. No cuticle  and thin cell wall : water and mineral are more easily to pass through
2. large surface area : facilitate water update
3. large vacuole : osmotic control
4. many mitochondria : provide energy for active transport of mineral salt

Mass flow hypothesis

Mechanism

1. At leaves,the sucrose concentration is high due to photosynthesis, which lower the water potential. Water moves in to phleom by osmosis from neighbouring cell and build up hydrostatic pressure.
2. At non-photosynthetic organ, the sucrose concentration is low due to respiration, which higher the water potential. Less water move in to phleom by osmosic from neighbouring cell and the hydrostatic pressure created is lower than those at the leaves.
3. A hydrostatic pressure gradient is built up between leaves and non-photosynthetic organ, which lead the liquid with sucrose in phloem is forced to move according to the hydrostatic pressure different, which is from leaves from non-photosynthetic organ.
4. Xylem provide a return path for water to refill.

 

Evidence

1. proved concentration different at leaves and non-photosynthatic organ
2. phloem sap is under pressure
3. When applying hormone to photosynthetic leaves, it only translocates downward. When applying hormone to non-photosynthetic leaves, it will not translocate downward. This indicate that the translocation does not cause by diffusion.

 

Problem

1. Why sieve tubes is living? what is the use of cytoplasmic strand?
2. Mass-flow rate is affected by temperature and metabolic inhibitors
3. bi-directional flow occur, which does not account
4. different molecule have different speed

Water transport in plant

A) Mechanism of water transpot along xylem:

1) Cohesion - tension developed from transpiration lead to massflow of water in xylem

1. Water is lost from lead by transpiration, developed water potential gradient, which constantly draws water from leaf xylem to leaf cell and from xylem to leaf xylem.
2. A negative pressure tension is created and pull water along the xylem vessel, water potential in root is lowered.
3. water draws in from soil to root by suction.

*cohesive forve between water molecuke enables water inside xylem unbreakable like a chain.

2) Root pressure:

1. Active transport of mineral ion from surrounding parenchyma endodermis by root into root xylem, which lower the water potential in xylem.
2. water is absorbed from soil to xylem by osmosis.
3. a positive pressure is created to push water upward along the xylem.

 

* only significant at night or soil moisture is high, which the transpiration pull is weak.

 

B) Movement of water and mineral salts across the root

From soil to root : (Active)

Root hair actively transpot mineral ion from soil to root hair, which lower the water potential in root hair vacuole. water is drawn across the cell well and the selectively permeable protoplasm by osmosis into vacuole.

From root hair to inner parenchyma : (Passive)

Water is than pass from root hair to parenchyma by the following mechanism:

1. vacuolar :(~0.1%) water drawn from vacuole to vacuole by osmosis
2. symplast :(~ 10%) water flows through the cytoplasm , diffusing from cell to cell via plasmodesmata.
3. apoplast :(~ 90%) water diffuses through the cellulose of adjascent cells and through the small intercellular spaces.

* driving force: transpiration of xylem , xylem develop low water potential , which countious remove water from inner parenchyma to xylem , producing necessary osmotic potential gradient for (1) and water potential gradient for (2) and (3).

From inner parenchyma to xylem : (Active)

Active transpot of mineral salt into stele, creating water potential gradient across root. Water flow from inner parenchyma to xylem, through the cytoplasm of the endodermis because the Casparian Strip around the cell wall is impermeable to water.

 

Gaseous exchange in plant

A) Guard cell:

sausage in shape : allow change of turgidity cause bending thich inner wall : allow bend in side substomatal space : allow gaseous diffusion chloroplast : allow photosynthetic product relay to change in shape

 

B) lenticel:

-layers of dead cells with lots of air space, air diffuse in through the air space to reach the living tissue.

special surface connected to inner system simple diffusion of gaseous smaller the pole, more efficient of gaseous exchange no control mechanism

 

C) root:

1. no cuticule, oxygen are free to diffuse
2. large surface area
3. intercellular spare in cortex, rapid diffusion of oxygen to inner system