Selekt1234
Badges: 10
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 2 years ago
#1
Hi there i have my exams in two weeks and i find module 4 boring coz my textbook just chats breeze and i wanted some helo from people who idid OCR A biology how they revised(is there any biology note ebsites) because i want to get an A biology
also i have a question
How does gas change takes place in an insect?
My textbook only mentions about tracheal system but does not explain how a tracheal system works
0
reply
liam.ro
Badges: 11
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 2 years ago
#2
The main features of the tracheal system that you need to understand are the spiracles, the trachea, and the tracheoles:

Spiracles: small openings (found across the waxy cuticle) where gases enter and leave; small bristles line their edges in order to filter air and trap moisture
Trachea: internal tubes following the spiracles that branch into tracheoles; they are held open by hard rings of chitin (taenidia)
Tracheoles: finer, fluid-lined internal tubes that can reach all tissue within the insect; their thin, fluid-lined walls contribute to efficient gaseous exchange (O2 dissolves into the fluid and becomes aqueous, leading to quicker diffusion)

Other points to note:

During vigorous movement, muscular contractions compress the tracheal tubes to facilitate ventilation, accommodating the larger need for respiration.
During vigorous movement, fluid in the tracheoles is drawn into the surrounding tissue, increasing the surface area available for gaseous exchange.
When spiracles open for gaseous exchange, water loss also takes place; hence, they must be controlled cleverly if water is scarce.
0
reply
Reality Check
Badges: 22
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
Report 2 years ago
#3
(Original post by Selekt1234)
Hi there i have my exams in two weeks and i find module 4 boring coz my textbook just chats breeze and i wanted some helo from people who idid OCR A biology how they revised(is there any biology note ebsites) because i want to get an A biology
also i have a question
How does gas change takes place in an insect?
My textbook only mentions about tracheal system but does not explain how a tracheal system works
Your textbook 'chats breeze'...
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

How would you describe the quality of the digital skills you're taught at school?

Excellent (37)
9.76%
Okay (110)
29.02%
A bit lacking (141)
37.2%
Not good at all (91)
24.01%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise