Written by students who passed Immediately available after payment Read online or as PDF Wrong document? Swap it for free 4.6 TrustPilot
logo-home
Other

Detailed topic 1 notes

Rating
-
Sold
-
Pages
25
Uploaded on
01-05-2025
Written in
2024/2025

These comprehensive A-Level Biology SNAB Topic 1 notes provide clear and detailed coverage of all essential concepts, including cell structure, biological molecules, membranes, and genetic inheritance. Designed specifically for the Edexcel Salters-Nuffield specification, the notes feature concise explanations, helpful diagrams, and key exam tips to support effective revision. Ideal for students aiming to deepen their understanding and improve exam performance, this well-organized document saves time and enhances learning by presenting complex topics in an accessible and engaging way.

Show more Read less
Institution
Course

Content preview

, 11. 9. 23
L1 - 1.1 - Transport in substance - ms Boyle

SA to volume ratio - Why do we need an Exchan'ge system?
• Human or mammals have a large size, increase in size of organism : surface area to
volume ratio decreases - the diffusion distance increasing hence metabolic rate
increase.
• Diffusion become insufficient. As result large organism have mass transport -
consisting of heart and circulation - move substance around the body and allows
gas change.
3 cubes X 3 cubes
2 cubesacubes
SA =
6 x 32 = 54
SA =
6x 28 = 24
r
V =
33 =
27
V = 23 =
8
SA: V =
SAIV =
54 : 27 =
54/27 2
=



SA : V =
SAIV =
24:8 = 2418:3


a cubes x4 cubes

SA = 6x42 =
96
V = 43 =
64
SA V
. -

SAIV =
96 64
. =
96/64 =
1 5
.




The bigger the Sa to volume ratio the faster the rate of diffusion

Human Earthworm m = am-

surface = 180 dm2 Surface = 0.36 dm2
volume = 68 dm2 M Volume = 0.0048 dm2·
180/68= 2.5
15 don't 0.36/0.0048 = 75 dm-

The earthworm has a higher SA to volume ratio which suggest that it has a smaller
diffusion distance and doesn’t need mass transport .

-we Have a specialized organs for gas ' exchange.
-Earthworm is moist better diffusion.
·

, L1 - 1.1 - The heart - ms Boyle 11. 9. 23


• four chambers - RL atrium and ventricle
• four main blood vessels -vena cave, aorta,
plumery vine plumery artery
• Atrioventricular valve - Tricuspid bicuspid -
separate atria from ventricle
• Semilunar valve - separate atria from ventricle
• Tendinous chords - prevent atrioventricular
from turning in and out due to pressure
• Septum - prevent oxygenated and deoxygenated
blood from mixing
• Cardiac muscle - thicker on LHS - pumps blood septumY
at high pressure. cardiac
muscle


Double circularly system - Passes through the heart twice
Why - respiration release energy - want to get blood around - get energy.


• The deoxygenated blood from the body Enters the vena cava and then travels to
Right atrium then into through the t-valveInto the right ventricle and pumps out
of the Pulmonary artery (way from the heart)
• The oxygenated blood from the lungs enter the Pulmonary vein (towards the
heart)into the left atrium and Through the b-valve it enters the left ventricle And
blood pump to the rest of the body throughAorta. N


Irregular beating of the heart is called - arrhythmia

Written for

Study Level
Examinator
Subject
Unit

Document information

Uploaded on
May 1, 2025
Number of pages
25
Written in
2024/2025
Type
OTHER
Person
Unknown

Subjects

CA$13.18
Get access to the full document:

Wrong document? Swap it for free Within 14 days of purchase and before downloading, you can choose a different document. You can simply spend the amount again.
Written by students who passed
Immediately available after payment
Read online or as PDF

Get to know the seller
Seller avatar
sidraahmad1

Get to know the seller

Seller avatar
sidraahmad1 Abacus College, Oxford
Follow You need to be logged in order to follow users or courses
Sold
-
Member since
1 year
Number of followers
0
Documents
1
Last sold
-

0.0

0 reviews

5
0
4
0
3
0
2
0
1
0

Recently viewed by you

Why students choose Stuvia

Created by fellow students, verified by reviews

Quality you can trust: written by students who passed their tests and reviewed by others who've used these notes.

Didn't get what you expected? Choose another document

No worries! You can instantly pick a different document that better fits what you're looking for.

Pay as you like, start learning right away

No subscription, no commitments. Pay the way you're used to via credit card and download your PDF document instantly.

Student with book image

“Bought, downloaded, and aced it. It really can be that simple.”

Alisha Student

Frequently asked questions