GRADE 9 NATURAL SCIENCE: MILKY WAY
Life and living Cytoplasm
Cell structure Cells - filled with jelly-like substance = cytoplasm.
Cell - basic structural, functional unit of all living Consists of water with complex collection of
organisms. structures, materials either dissolved / suspended in it.
Cells - small they can only be seen under microscope. Cytoplasm provides liquid medium for all chemical
Anything can only be seen using microscope = reactions that take place inside cell.
microscopic.
All cells, whether they plant / animal cells have same Nucleus
basic structure. All living cells contain DNA.
Simplest cells, - bacteria, DNA occurs in cytoplasm.
In plant, animal cells, DNA contained in nucleus.
Nucleus - round organelle surrounded by nuclear
membrane.
Nucleus contains deoxyribonucleic acid (DNA).
DNA contains information that determines organism's
inherited characteristics.
In humans, DNA determines characteristics - eye
colour / hair colour.
The general structure of a cell Each person's DNA is unique: different from everyone
else's.
Cell membrane Children inherit mixture of mother and father's DNA.
Cell membrane forms outer boundary of cell. Process allows people to look different from each
Surrounds contents of cell. other.
Membrane selectively permeable. Process accounts for variation within single species.
Means it controls which materials pass into / out of
cell.
, GRADE 9 NATURAL SCIENCE: MILKY WAY
Organelles Plant cells differ from animal cells in three main ways:
Each of organelles listed below performs different They have cell wall that surrounds cell on outside of cell
functions for cell. membrane.
Organelles - quite large structures found in cytoplasm Made of cellulose, - rigid material.
of cells. Cell wall provides cell with support, protection.
Nucleus - example of an organelle + other organelles Animal cells have no cell wall because organisms usually
supported, protected by skeleton.
that occur in cells.
They have chloroplasts.
While some organelles occur in both plant and animal
Chloroplast - special organelle contains chlorophyll.
cells, others found in only one type of cell. Green pigment absorbs light energy from sun, converts
Mitochondria found in both plant & animal cells. into energy-rich glucose = photosynthesis.
Respiration, metabolic reaction that releases energy Glucose stored as starch which used as food for plant.
from glucose, takes place in mitochondria. Animals unable to make own food by process of
Vacuoles - fluid-filled sacs surrounded by membrane. photosynthesis -they have no chloroplasts.
Used to store substances which can then be used by They usually have large vacuoles.
cell. Contrast, animal cells usually not have vacuoles / they
Animal cells usually have several small vacuoles / no present, very small.
vacuoles at all while plant cells usually have large
vacuoles which store substances - sugar, salts, water
for cell.
Chloroplasts only found in plant cells.
Photosynthesis takes place in chloroplasts.
Differences between plant and animal cells
Plants, animals appear different from each other -
their cells are different. The structure of a typical plant cell
, GRADE 9 NATURAL SCIENCE: MILKY WAY
What is a microscope?
Microscope - instrument that contains one / more
magnifying lenses.
Allows us to look at things that are too small to see
with naked eye.
Compound light microscope - common tool used in
biology = "compound" microscope - has more than
one lens, "light" microscope - uses light to view
The structure of a typical animal cell specimen.
Contrast, electron microscope uses beams of electrons
Microscope to make image of specimen.
What is a wet mount slide?
Wet mount slide - type of microscope slide can be
prepared quickly, easily by biologist in order to look at
something under microscope.
Called wet mount because specimen placed in drop of
liquid on microscope slide.
Liquid used - usually water.
Some cases dye may be added to water to stain cells /
part of cells to make them more visible.
, GRADE 9 NATURAL SCIENCE: MILKY WAY
Cells in tissues, organs and systems Group of cells performing specific function form tissue,
Cells come in many different shapes, sizes, organisms group of tissues make up organ, organs working
made up of different numbers of cells. together in group’s form systems, systems make up
Some microscopic organisms, bacteria, consist of organism.
single cell.
Means all life processes, - feeding, respiration, Cells All living organisms are made up of cells
excretion, reproduction, carried out within one cell. Tissue Tissue - group of cells all have same structure,
Organisms consist of single cell = unicellular perform same function
organisms. Organ Organ made up of group of different tissues
Contrast, macroscopic organisms - humans, made up perform single function.
of thousands of cells. Example, heart made of muscle tissue,
Organisms consist of large numbers of cells = multi- connective tissue, nerve tissue, blood.
cellular. All tissues work together to pump blood
around body
Impossible for every cell to carry out all life processes
System System consists of group of different organs
needed to keep large, complex organisms like humans
work together to perform bodily function for
alive.
organism.
These organisms, groups of cells will specialise so they Some of organs make up digestive system =
are able to perform specific function. stomach, small intestine, large intestine.
Each specialised group of cells have same shape, Different organs work together to digest food,
structure. absorb nutrients
Example, muscle cells able to contract, relax to enable Organism Organism made up of number of different
body to move. systems which all work together to keep
organism alive.
Tissues, organs and systems Humans have seven systems:
Multi-cellular organisms made up of many cells all − digestive system
work together to keep organism alive. − circulatory system
Life and living Cytoplasm
Cell structure Cells - filled with jelly-like substance = cytoplasm.
Cell - basic structural, functional unit of all living Consists of water with complex collection of
organisms. structures, materials either dissolved / suspended in it.
Cells - small they can only be seen under microscope. Cytoplasm provides liquid medium for all chemical
Anything can only be seen using microscope = reactions that take place inside cell.
microscopic.
All cells, whether they plant / animal cells have same Nucleus
basic structure. All living cells contain DNA.
Simplest cells, - bacteria, DNA occurs in cytoplasm.
In plant, animal cells, DNA contained in nucleus.
Nucleus - round organelle surrounded by nuclear
membrane.
Nucleus contains deoxyribonucleic acid (DNA).
DNA contains information that determines organism's
inherited characteristics.
In humans, DNA determines characteristics - eye
colour / hair colour.
The general structure of a cell Each person's DNA is unique: different from everyone
else's.
Cell membrane Children inherit mixture of mother and father's DNA.
Cell membrane forms outer boundary of cell. Process allows people to look different from each
Surrounds contents of cell. other.
Membrane selectively permeable. Process accounts for variation within single species.
Means it controls which materials pass into / out of
cell.
, GRADE 9 NATURAL SCIENCE: MILKY WAY
Organelles Plant cells differ from animal cells in three main ways:
Each of organelles listed below performs different They have cell wall that surrounds cell on outside of cell
functions for cell. membrane.
Organelles - quite large structures found in cytoplasm Made of cellulose, - rigid material.
of cells. Cell wall provides cell with support, protection.
Nucleus - example of an organelle + other organelles Animal cells have no cell wall because organisms usually
supported, protected by skeleton.
that occur in cells.
They have chloroplasts.
While some organelles occur in both plant and animal
Chloroplast - special organelle contains chlorophyll.
cells, others found in only one type of cell. Green pigment absorbs light energy from sun, converts
Mitochondria found in both plant & animal cells. into energy-rich glucose = photosynthesis.
Respiration, metabolic reaction that releases energy Glucose stored as starch which used as food for plant.
from glucose, takes place in mitochondria. Animals unable to make own food by process of
Vacuoles - fluid-filled sacs surrounded by membrane. photosynthesis -they have no chloroplasts.
Used to store substances which can then be used by They usually have large vacuoles.
cell. Contrast, animal cells usually not have vacuoles / they
Animal cells usually have several small vacuoles / no present, very small.
vacuoles at all while plant cells usually have large
vacuoles which store substances - sugar, salts, water
for cell.
Chloroplasts only found in plant cells.
Photosynthesis takes place in chloroplasts.
Differences between plant and animal cells
Plants, animals appear different from each other -
their cells are different. The structure of a typical plant cell
, GRADE 9 NATURAL SCIENCE: MILKY WAY
What is a microscope?
Microscope - instrument that contains one / more
magnifying lenses.
Allows us to look at things that are too small to see
with naked eye.
Compound light microscope - common tool used in
biology = "compound" microscope - has more than
one lens, "light" microscope - uses light to view
The structure of a typical animal cell specimen.
Contrast, electron microscope uses beams of electrons
Microscope to make image of specimen.
What is a wet mount slide?
Wet mount slide - type of microscope slide can be
prepared quickly, easily by biologist in order to look at
something under microscope.
Called wet mount because specimen placed in drop of
liquid on microscope slide.
Liquid used - usually water.
Some cases dye may be added to water to stain cells /
part of cells to make them more visible.
, GRADE 9 NATURAL SCIENCE: MILKY WAY
Cells in tissues, organs and systems Group of cells performing specific function form tissue,
Cells come in many different shapes, sizes, organisms group of tissues make up organ, organs working
made up of different numbers of cells. together in group’s form systems, systems make up
Some microscopic organisms, bacteria, consist of organism.
single cell.
Means all life processes, - feeding, respiration, Cells All living organisms are made up of cells
excretion, reproduction, carried out within one cell. Tissue Tissue - group of cells all have same structure,
Organisms consist of single cell = unicellular perform same function
organisms. Organ Organ made up of group of different tissues
Contrast, macroscopic organisms - humans, made up perform single function.
of thousands of cells. Example, heart made of muscle tissue,
Organisms consist of large numbers of cells = multi- connective tissue, nerve tissue, blood.
cellular. All tissues work together to pump blood
around body
Impossible for every cell to carry out all life processes
System System consists of group of different organs
needed to keep large, complex organisms like humans
work together to perform bodily function for
alive.
organism.
These organisms, groups of cells will specialise so they Some of organs make up digestive system =
are able to perform specific function. stomach, small intestine, large intestine.
Each specialised group of cells have same shape, Different organs work together to digest food,
structure. absorb nutrients
Example, muscle cells able to contract, relax to enable Organism Organism made up of number of different
body to move. systems which all work together to keep
organism alive.
Tissues, organs and systems Humans have seven systems:
Multi-cellular organisms made up of many cells all − digestive system
work together to keep organism alive. − circulatory system
