Understanding and Comparing

Understanding and

Comparing

Transport Systems in

Plants and Animals

Transport in Plants and Animals

Qu. Consider the following systems. What are

they composed of, and how are they similar to

each other?




each other?

Urban transport system. Solar system. Legal

system. Circulatory system. Electrical system

(bulb, batteries and wires).




each other?

Ans. Systems are composed of elements that

interact in order to achieve a common

purpose. Systems follow rules.

Urban transport system. Solar system. Legal

system. Circulatory system. Electrical system

(bulb, batteries and wires).

Qu. What basic things do all living organisms

need in order to survive?


Qu. What basic things do all living organisms

need in order to survive?


Ans. Food, air and water.

Ans. Organisms may also need shelter from the

weather and also from predators.

(Maslow’s Hierarchy of Needs).


Qu. Why are transport systems necessary in

multicellular organisms?




Ans. Multicellular organisms require transport

systems to supply their cells with nutrients and

oxygen, and remove waste products. As the size

of an organism increases, its surface area to

volume ratio decreases.




• Total surface area =

1 × 1 × 6 = 6 cm2

• Total volume =

1 × 1 × 1 = 1 cm3

• Surface area to

volume ratio =

6 : 1




• Total surface area =

2 × 2 × 6 = 24 cm2

• Total volume =

2 × 2 × 2 = 8 cm3

• Surface area to

volume ratio =

24 : 8 = 3 : 1




Ans. This means it has relatively less surface

area available for substances to diffuse through,

so the rate of diffusion may not be fast enough

to meet its cells requirements.




Ans. Large multicellular organisms therefore

cannot rely on diffusion alone to supply their

cells with substances such as nutrients and

oxygen, and to remove waste products.

Large multicellular organisms require

specialised transport systems.

Qu. In what locations are most of the world’s

capital cities built? Historically, why did our

ancestors choose to build cities in these locations?


Qu. In what locations are most of the world’s

capital cities built? Historically, why did our

ancestors choose to build cities in these locations?


Ans. Most of the world's major cities were built on

or around areas of freshwater (lakes and rivers).

Our ancestors chose to settle near these areas as

rivers were a means of supplying drinking water

for their families and livestock, as a food supply,

used for irrigating crops and as a means of

transport in order to aid commerce.

Qu. What connections can you see between the

city of Venice and a multicellular organism?


Qu. What connections can you see between the

city of Venice and a multicellular organism?


Ans. The buildings within the city are similar to

cells within an organ. The main river is analogous

to an artery, and the canals and roads are similar

to veins and capillaries. Just like a multicellular

organism, the city has a transport system to supply

essential services (nutrients) and remove waste.

The elements of the transport system within the

city work together towards achieving a

common goal by following certain rules.


Qu. Which multicellular organisms do not require

transport system? Explain your reasoning.




Ans. Sea sponge (large surface area).




Ans. Jellyfish (large surface area).


• Transport in Plants.


• Osmosis is the net movement of water

molecules from a region of high water

potential to a region of low water potential

across a selectively permeable membrane.


• High water

potential.

• Low water

potential.


• Root structure. The root hair cells absorb water

from the soil by osmosis.


• Water moves from a region of higher water

potential (in the soil) to a region of lower

water potential (inside root hair cells).


• Water is transported

from the roots to the

leaves in the xylem by

transpiration.

• Sugars are transported

from the leaves to the

roots in the phloem.


• In the leaf, some of the water chemically

combines with carbon dioxide to form glucose

in the presence of sunlight (photosynthesis).


• Water also exits the leaf of the plant through

pores called stomata. This draws more water

up through the roots and xylem (transpiration).


Qu. Why do plants not require a pump (heart) to

move solutions through the phloem and xylem?


Qu. Why do plants not require a pump (heart) to

move solutions through the phloem and xylem?

Ans. Water rises up through the xylem of the

plant by a process known as transpiration. As

water evaporates in the spongy mesophyll and

exits the leaf through the stomata, more water is

drawn up through the xylem. This is a passive

process and does not require the plant to

expend any energy.


• Transport in Insects.

Insects have an open circulatory system.

Transport in Plants and AnimalsQu. What are the similarities and differences

between the circulatory system of a fish and the

circulatory system of a mammal?

• Fish • Mammal

Transport in Plants and AnimalsQu. What are the similarities and differences

between the circulatory system of a fish and the

circulatory system of a mammal?

• Fish • Mammal

Two

chambered

heart.

Single

circulatory

system.

Four

chambered

heart.

Double

Circulatory

system.

Muscular heart,

with valves, beats

quickly and

continuously.


• Transport in Fish.

Fish have a single circulatory system

With a two chambered heart.

Transport in Plants and Animals• Fish have a single

circulatory system with a

two chambered heart.

• The heart pumps

deoxygenated blood

through the gills.

Oxygenated blood is

then circulated around

the rest of the body.

• There is only one

system for both the

oxygenated and

deoxygenated blood.


• Transport in Mammals.

Mammals have a double circulatory system

with a four chambered heart.


• Mammals have a

double circulatory

system with a four

chambered heart.

• The heart pumps

oxygenated and

deoxygenated

blood through two

separate systems.

• Oxygenated and

deoxygenated

blood do not mix.


Qu. What are the advantages of having a

four chambered heart?


Qu. What are the advantages of having a

four chambered heart?

Ans. Oxygenated blood and deoxygenated blood

are kept separate from each other. This is a very

efficient way of circulating blood around the

body. Blood from the left ventricle is fully

oxygenated, and this will be distributed around

the body to ‘power’ the metabolic reactions. In

the two chambered heart of a fish, oxygenated

and deoxygenated blood are

not separated.


Qu. Which animals do you think might have a

three chambered heart? Explain your reasoning.




Ans. Amphibians have three chambered hearts.




Ans. In terms of evolution, amphibians are

somewhere between fish (2) and mammals (4).


Qu. What stages of development do you think

the circulatory system of a human foetus goes

through?


Qu. What stages of development do you think

the circulatory system of a human foetus goes

through?

• There is a fish in all of us!

• This is because we share a

common ancestor.


Qu. What is a hole in the heart? How does it affect

the circulatory system and how hight it be treated?




Ans. A hole in the septum between the left and

right ventricles allows oxygenated and

deoxygenated blood to mix, which reduces the

efficiency of the circulatory system.




Ans. It is almost impossible to operate on a

beating heart. One interesting, yet dangerous,

solution is to induce hypothermia in the patient.

The patient’s body is cooled from 37C to just

18C. This slows all metabolic processes, the

pulse rate slows, and the heart stops beating.




Ans. No oxygenated blood flows around the

body, but none is needed because all metabolic

processes have essentially stopped. This gives

the surgeon a window of opportunity to stitch-up

the hole in the septum before warming the

patient’s body, causing the heart to start beating

once again.

Qu. Synthesis and evaluation. What are

the advantages and disadvantages of

taking a drug orally (enters through the

digestive system) and taking a drug

through intravenous injection (directly

into the circulatory system)?



• Oral

Advantages

• Intravenous

Injection

Advantages

• Oral

Disadvantages

• Intravenous

Injection

Disadvantages


• Oral

Advantages

Self medication.

No special equipment.

Convenient dosage.

• Injection

Advantages

Rapidly absorbed and

transported, hence fast

acting.

• Oral

Disadvantages

Drug maybe digested.

Slow to absorb, transport

and act.

• Injection

Disadvantages

Requires special

equipment.

Maybe painful.


Qu. What are the structures and properties of

the different blood vessels?


Qu. What are the structures and properties of

the different blood vessels?

Arteries Capillaries Veins

• Carry blood from the

heart at a high

pressure.

• Thick muscular wall

to withstand the high

pressure.

• Absorb / release

chemicals from

surrounding tissues by

diffusion.

• Thin cell walls and

large surface area.

• Return blood back to

the heart under low

pressure.

• Thin muscular wall.

• Valves prevent blood

flowing backwards

through the vein.


Qu. How do oxygen and nutrients move from the

blood into the cells of the body?




Ans. Chemicals move from the blood into the

surrounding tissues by the process of diffusion:

Chemicals move from a region of higher

concentration to a region of lower concentration.

Chemicals also enter and exit cells across the

selectively permeable cell membrane by the

process of diffusion.


Presentation by Dr. Chris Slatter

[email protected]

Nanyang Girls’ High School

2 Linden Drive

Singapore

288683

14th July 2020

Understanding and Comparing

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