Olivier Natural Sciences Theory and Workbook Grade 9 - Life and Living (Chapter 1) Summary
125 views 0 purchase
Course
Life Sciences
Institution
9th Grade
Summary of chapter 1 (Life and Living) of the Olivier Natural Sciences Theory and Workbook Grade 9 Textbook (ISBN: 978-0-) that contains all key concepts and explanations.
olivier natural sciences theory and workbook grade 9
Written for
9th Grade
Life Sciences
200
All documents for this subject (30)
Seller
Follow
e-lonescheepers
Reviews received
Content preview
1
Grade 9 Olivier Natural Sciences Theory and Workbook
Ch
Life and Living
Cells as the Basic Units of Life
CELL STRUCTURE
Since they are macroscopic, cells are invisible to the
human eye. DEFINITION OF A CELL :
The only way to view cells is with a microscope. The fundamental structural and
Animal and plant cells are the two different types of cells. operational unit of all living things
Although the structure and function of plant and animal is the cell.
cells are different, all plant and animal cells have basic
structural components.
Similarities between plant and animal cells DEFINITION OF ORGANELLES :
The cell membrane, nucleus, cytoplasm, and organelles are Organelles are structures in the
shared by all animal and plant cells. cell’s cytoplasm that carry out cell
Organelles are structures that exist in the cytoplasm of the functions.
cell, including mitochondria and vacuoles.
, 2
Grade 9 Olivier Natural Sciences Theory and Workbook
Elements of plant & Characteristics Functions
animal cells
Cell membrane It is a thin, pliable membrane The contents of the cell are contained by it.
that is alive (layer or skin). It is a selective or semi preamble
membrane (only certain substances are
allowed to move in or out of the cell).
Cytoplasm It is a jelly-like fluid that It has organelles, which are microscopic
completely fills the cell's membrane-like structures that serve particular
cavity. purposes.
It includes several organelles Here, chemical processes are in motion.
and food particles. It upholds and preserves the cell's form.
Nucleus In every live cell, there is a It manages every aspect of the cell's life.
spherical structure called the It is a component of the cell known as the "brain."
nucleus. Deoxyribonucleic acid, or DNA, is found in the
It has the nuclear membrane nucleus and is responsible for determining
covering it. inherited traits like eye colour and height.
It has a substance called (DNA houses the genetic code that makes each
nucleoplasm in it. living thing distinct. Each of us is unique because
Its interior contains a of the information and variances in our DNA.)
nucleolus, a tiny, dense
structure.
It often resides towards the
cell's centre in animal cells.
The nucleus is located at the
cell's border in plant cells.
Organelles Plant and animal cells include vacuoles and mitochondria (singular form:
mitochondrion) in their cytoplasm.
Mitochondria Small, spherical organelles As they create the energy (known as cellular
called mitochondria are found respiration) required for cells to perform life
in the cytoplasm of both plant functions, mitochondria are also known as the
and animal cells. "powerhouse" of the cell.
A cell's function determines how many
mitochondria are present in the cell.
Since they need a lot of energy, muscle and liver
cells have many mitochondria.
Vacuoles Vacuoles are active organelles that are mostly found in plant cells.
Animal cells have modest vacuoles compared to the size of the vacuoles in plant
cells.
Plant cells have persistent vacuoles.
Animal cells either lack or have transient vacuoles.
Differences between plant and animal cells
Animal cells and plant cells are distinct.
Chloroplasts, cell walls, and big vacuoles are all features of plant cells.
Animal cells do not have these structures.
, 3
Grade 9 Olivier Natural Sciences Theory and Workbook
Elements only Characteristics Functions
present in plant
cells
Cell wall The cell wall is the plant cell's The cell's wall lends it its distinct shape and
outermost layer (rigid outer durability.
framework of the cell). It guards against harm to the cell's interior.
It is strong, inflexible, and
non-living.
Most soluble things can pass
through it.
It is primarily made up of
cellulose (a type of
carbohydrate).
Chloroplasts The cytoplasm of plant cells The energy of the sun is captured by chlorophyll,
contains oval-shaped which then creates energy-dense food (glucose and
organelles called starch) for the plant along with carbon dioxide and
chloroplasts. water.
It only appears in the plant's Photosynthesis is the name given to the process.
green parts, such the leaves
and stems.
Chlorophyll, a pigment found
in it, is what gives the plant its
green colour.
Large vacuoles In plant cells, there is often The support provided by vacuoles allows the plant
just one big vacuole. cell to keep its form.
It is the region of the It offers food and waste product storage space.
cytoplasm that the tonoplast (Animal cells may have vacuoles, however they are
membrane surrounds. typically tiny and transient. Animal cells can also
Cell sap is a fluid that fills the exist without any vacuoles at all.)
empty area inside the vacuole.
SUMMARY OF THE CELL STRUCTURE
Similarities between plant and animal cells:
Characteristics Plant Cells Animal Cells
Cell Has a cell membrane. Has a cell membrane.
membrane
Cytoplasm Cytoplasm is present. Cytoplasm is present.
Nucleus Contains a nucleus. Contains a nucleus.
Mitochondria Mitochondria are present in the Mitochondria are present in the cytoplasm.
cytoplasm.
Vacuoles The cytoplasm contains a single The cytoplasm contains numerous small vacuoles (if
large vacuole. vacuoles are present at all).
Differences between plant and animal cells:
Characteristics Plant Cells Animal Cells
Cell shape Due to the presence of a cell wall, it has a Due to the absence of a cell wall, it has a
rigid, firm and sturdy shape. flexible or changeable shape.
Cell wall Has a firm cell wall. Has no cell wall.
Chloroplasts There are chloroplasts present in the The cytoplasm contains no chloroplasts.
cytoplasm that are responsible for
photosynthesis.
Vacuoles The cytoplasm contains a single large The cytoplasm contains numerous small
vacuole. vacuoles (if vacuoles are present at all).
, 4
Grade 9 Olivier Natural Sciences Theory and Workbook
CELLS IN TISSUE, ORGANS, AND SYSTEMS
A living organism is made up of various kinds of cells.
These cells come in a variety of sizes and forms and serve a variety of purposes.
Cellular differentiation and specialisation
Only when the number of cells rises can growth occur in plants (and other multicellular creatures).
A unique mechanism in which a mature cell divides into two daughter cells, which then develop into
maturity and subdivide, results in an increase of cells.
In a multicellular plant or animal, not every cell is the same.
Enzymes, which are chemical agents that regulate various
cellular functions, work to guarantee that cells divide in a
manner that causes them to develop in a way that makes
them structurally distinct from one another.
Differentiation, the term for these variations, is intended to
give cells certain functions.
The cells are therefore specialized.
As a result, cells are adaptable and have various shapes
and structures to carry out various jobs.
Certain cells defend the body from the invasion of
pathogens (e.g. skin cells).
Some cells are crucial in the movement of chemicals (e.g.
the red blood cells that transport oxygen).
Nerve cells (neurons), for example, are cells that transport
impulses to and from the brain.
Some cells can relax and contract (e.g. muscle cells). Source:
https://za.pinterest.com/pin/2800676705564
07047/
Single-celled organisms
Unicellular organisms are microscopic creatures that often only have one cell, like bacteria, amoebas,
and some types of algae.
Each cell in these organisms houses all the processes necessary for life.
Thus, respiration, secretion, respiration, reproduction, and breathing are all carried out by the same
cell.
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 e-lonescheepers. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $2.85. You're not tied to anything after your purchase.
