Interview
IB Biology: Unit 1 - Cell biology
- Course
- Institution
- Book
Clear and consise notes on unit 1 - cell biology of the IB SL biology course.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
Biodiversidad- Biología IB NM
-
Nutrición- Biología IB NM
-
Tema Biología IB: Ecosistemas
Seller
Follow
simonkam
Content preview
Unit 1 - Cell Biology1.1 - Introduction to Cells
The evolution of multicellular organisms allowed cell specialization and cell replacement.
Cell theory:
1. All living things are made of 1 or more cells
2. The cell is the smallest unit of life (able to sustain life alone)
3. All cells come from preexisting cells
Exceptions:
1) Skeletal muscle
● Many nuclei
2) Fungal hyphae
● Many nuclei
3) Giant algae
● Gigantic size
● 3 distinct anatomical (resemble unique cells)
Functions of life:
● Metabolism: chemical reactions inside the cell
● Response to the environment
● Homeostasis: keeping balance
● Growth: irreversible increase in size
● Reproduction: often asexual cloning
● Excretion: expulsion of waste (the useless stuff)
● Nutrition: obtain food for energy/growth
Memonic: Mr. H. Green
examples:
1) Paramecium
● Metabolism
○ In the cytoplasm
● Response
○ Cilia (hair-like structures) move the cell towards food
● Homeostasis
○ Water levels (managed by vacuoles that store extra water)
● Growth
○ Increases in size until cell division
● Reproduction
○ Asexsual reproduction (cell division)
● Excretion
○ Waste diffuses (through cell membrane) such as CO2
● Nutrition
○ Absorbed through endocytosis
2) Chlorella
, ● Metabolism (same)
● Response (same but needs light not food)
● Homeostasis (same)
● Growth (same)
● Reproduction (same)
● Excretion (same)
● Nutrition
○ Food is made inside the cell through photosynthesis
Magnification:
i
m=
a
Where: m is magnification, i is image (on paper), a is actual (in real life)
Cell size and surface area (SA) to volume (V) ratio:
● Surface area (SA) determines how much can be
○ Absorbed
■ eg. food, oxygen, etc
○ Excreted
■ eg. waste
● Volume (V) determines how much
○ Nutrients is needed
○ Waste is created
● As V increases, SA decreases
○ These are in negative correlation but have positive correlation needs
○ Thus the smaller the cell the more efficient it is
■ Thus cells stay small
The parts don’t explain the whole:
● Organisms have properties that emerge from the interaction of their cellular components.
● Cells interact to produce a tissue/organ/organism that can do things none of the
individual cells could do
● Eg. the brain
○ Cannot be explain by neurons (their functioning) alone
Cell specialization:
● Specialized cells develop through cell differentiation
● Differentiation explained:
○ Every cell has the same genes
■ Some genes are expressed (active
■ Others are non expressed (inactive)
○ A group of differentiated cells becomes a tissue
● Differentiation happens due to outside factors:
○ Neighbouring cells
■ Hormones
Stem cells:
What are stem cells:
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller simonkam. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53068 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now