EXCHANGE AND TRANSPORT mod 3

Question 1

What do all organisms need to exchange with their environment?

Answer 1

Substances like oxygen, glucose, and waste products such as carbon dioxide and urea.

Question 2

Which type of organisms have a higher surface area to volume ratio?

Answer 2

Smaller animals.

Question 3

How do you calculate the surface area to volume ratio?

Answer 3

Divide the surface area by the volume.

Question 4

How do single-celled organisms exchange substances?

Answer 4

Through diffusion directly across the cell surface membrane.

Question 5

What makes diffusion across the outer membrane too slow in multicellular animals?

Answer 5

Several reasons, including distance from cells to the outside environment and low surface area to volume ratio.

Question 6

What do multicellular animals need instead of straightforward diffusion?

Answer 6

Specialised exchange surfaces. (lungs/gills in the ventilation system, and a specialised transport system to carry molecules around the body, like a good blood supply)

Question 7

Give an example of a specialised exchange surface in multicellular organisms.

Answer 7

The alveoli in the lungs.

Question 8

How do root hair cells increase the rate of absorption?

Answer 8

By providing a large surface area for water and mineral ions absorption

Root hair cells grow into long ‘hairs’ that stick out into the soil.

Question 9

What is the role of the thin alveolar epithelium?

Answer 9

Decreases the distance for O2 and CO2 diffusion, increasing the rate of diffusion

This structure facilitates efficient gas exchange in the lungs.

Question 10

How does a good blood supply affect alveoli?

Answer 10

Maintains concentration gradients of O2 and CO2

A large capillary network surrounds each alveolus, constantly removing oxygen and bringing in carbon dioxide.

Question 11

What are fish gills responsible for?

Answer 11

Gas exchange between the fish’s blood and surrounding water

Gills exchange O2 and CO2 efficiently due to their structure and blood supply.

Question 12

How do the features of fish gills contribute to gas exchange?

Answer 12

They contain a large network of capillaries and are well-ventilated

This setup helps maintain a concentration gradient for O2, enhancing diffusion into the blood.

Question 13

What are the primary components of the gaseous exchange system in mammals?

Answer 13

Lungs, trachea, bronchi, bronchioles, alveoli, diaphragm, intercostal muscles, ribcage

Question 14

What are bronchioles?

Answer 14

Smaller tubes branching from the bronchi that end in alveoli

They facilitate the movement of air to the alveoli.

Question 15

What are alveoli?

Answer 15

Small air sacs where gas exchange occurs

They are the final destination for air in the lungs.

Question 16

What is the role of goblet cells in the gaseous exchange system and where are they found?

Answer 16

Goblet cells secrete mucus to trap microorganisms and dust and are found in the trachea and bronchi.

This prevents harmful particles from reaching the alveoli.

Question 17

What function do cilia serve in the airways?

Answer 17

Cilia beat to move mucus upward towards the throat

This action helps to prevent lung infections by clearing trapped particles.

Question 18

What is the function of elastic fibres in the respiratory system and where are they found?

Answer 18

Elastic fibres help the lungs inflate and recoil during breathing and are found in the walls of trachea, bronchi, bronchioles and alveoli.

Question 19

What role does smooth muscle play in the trachea and bronchi?

Answer 19

Smooth muscle controls the diameter of the airways

It relaxes during exercise to allow more airflow.

Question 20

What is the purpose of the rings of cartilage in the trachea and bronchi?

Answer 20

Rings of cartilage provide support to prevent collapse during breathing

They maintain the structure of the airways.

Question 21

What are the two processes involved in ventilation?

Answer 21

Inspiration and expiration

Inspiration is breathing in, while expiration is breathing out.

Question 22

What muscles are involved in the process of ventilation?

Answer 22

Diaphragm, internal intercostal muscles, external intercostal muscles

These muscles control the movements of the ribcage.

Question 23

What happens during inspiration?

Answer 23

1. External intercostal and diaphragm muscles contract causing the ribcage to move upwards and outwards, and diaphragm to flatten.

Question 24

What is the effect of diaphragm contraction during inspiration?

Answer 24

The diaphragm flattens, increasing thoracic volume

This leads to a decrease in lung pressure, allowing air to flow in.

Question 25

Is inspiration an active or passive process?

Answer 25

Active process It requires energy to occur.

Question 26

What occurs during expiration?

Answer 26

External intercostal and diaphragm muscles relax ## Footnote The ribcage moves downwards and inwards and the diaphragm becomes curved, decreasing volume of the thorax

Question 27

What is the result of thoracic volume decrease during expiration?

Answer 27

Air pressure increases, forcing air out of the lungs ## Footnote Expiration is usually a passive process.

Question 28

What is tidal volume (TV)?

Answer 28

The volume of air in each breath, usually about 0.4 dm³ ## Footnote Tidal volume is a key measure of breathing.

Question 29

What is vital capacity?

Answer 29

The maximum volume of air that can be breathed in or out ## Footnote Important for assessing lung function.

Question 30

What is breathing rate?

Answer 30

How many breaths are taken, usually measured per minute ## Footnote It can vary based on activity level.

Question 31

What does oxygen consumption refer to?

Answer 31

The rate at which an organism uses up oxygen ## Footnote Measured in dm³ used per minute.

Question 32

What happens during forced expiration?

Answer 32

Internal intercostal muscles contract ## Footnote This pulls the ribcage down and in.

Question 33

What does a spirometer do?

Answer 33

Spirometers are machines that give readings of tidal volume, vital capacity, breathing rate and oxygen uptake.

Question 34

What are the steps to using a spirometer?

Answer 34

1) Person breathes through tube connected to the oxygen chamber (the oxygen chamber has a moveable lid) 2). As the person breathes in an out, lid moves up and down. 3). These movements can be recorded by a pen attached to the lid of the chamber, which writes on a rotating drum, creating a spirometer trace. OR the spirometer can be attached to a motion sensor which uses movements to produce electric signals that are picked up by a data logger. 4) The soda lime in the tube that the subject breathes into absorbs carbon dioxide. ❤️🫁

Question 35

What system do fish use for gas exchange?

Answer 35

Counter-current system - they need this because there’s a lower concentration of oxygen in water than in air (water, containing oxygen, enters the fish through its mouth and passes out through the gills)

Question 36

What is the name of the thin branches that make up fish gills?

Answer 36

Gill filaments or primary lamellae (They provide a big surface area for exchange of gases and are covered in tiny gill plates -secondary lamellae- which increases the SA even more!!)

Question 37

What is the counter current system and how does it work?

Answer 37

Blood flows through gill plates in one direction, and water flows in the opposite direction. 💦 🩸 It maintains a large concentration gradient between water and blood. The concentration of oxygen in the water is always higher than in the blood, so as much oxygen as possible diffuses from water into the blood 🩸

Question 38

What is the process of gill ventilation in fish?

Answer 38

The gill ventilation process in fish involves several steps: 1. Mouth Opening: The fish opens its mouth, allowing water to enter the buccal cavity. 2. Buccal Cavity Expansion: The floor of the buccal cavity lowers, increasing the volume and decreasing pressure, which draws water in. 3. Operculum Movement: The operculum remains closed during this phase to retain water in the gills. 4. Water Flow Over Gills: The fish then closes its mouth, raising the floor of the buccal cavity, which increases pressure and forces water over the gill filaments. 5. Gas Exchange: Oxygen diffuses from the water into the blood, and carbon dioxide diffuses from the blood into the water. 6. Operculum Opening: The operculum opens to allow the water to exit, completing the cycle.

Question 39

What are the steps to dissecting fish gills?

Answer 39

1- Wear a lab coat and gloves 2 - Place salmon in dissection tray 3- Push back operculum, use scissors to remove the gills. Cut each gill arch through at the bone at the top and bottom. 4 - You should be able to see gill filaments, draw and label it.

Question 40

What do insects use for gas exchange?

Answer 40

Trachaea

Question 41

What are the steps to insect ventilation?

Answer 41

1 - They have air-filled pipes called tracheae. 2 - Air moves into the tracheae through pores on the insect surface called spiracles 3 - Oxygen travels down the concentration gradient towards the cells, Carbon Dioxide from the cells moves down its own concentration gradient towards the spiracles to be released. 4 - Tracheae branch off into tracheoles, which have thin permeable walls that lead to individual cells. Tracheoles also contain fluid which oxygen dissolves in. 5 - The oxygen then diffuses from this fluid into body cells, CO2 diffuses in the opposite direction. 6 - Insects use rhythmic abdominal movements to change the volume of their bodies and move air in and out of spiracles. Also use wing movements to pump their thoraxes.

Question 42

Name the structure on an insect surface that allow air to enter the tracheae.

Answer 42

pores on the surface - Spiracles

Question 43

What are the steps to insect dissection?

Answer 43

1 - Fix insect to dissecting board with pins. 2 - Cut and remove piece of exoskeleton from along the length of the insect’s abdomen. 3 - Use syringe to fill abdomen with Salene solution to see network of thin, grey tubes ( Tracheae ) 4 - Examine tracheae using light microscope and wet mount slide and observe rings of chitin (for support)