Teacher:BETTER LEARNING
9TH GRADE
BIOLOGY CHEAT SHEET
___
Notes
CELL
● All living bodies are made up of cells
● Organisms that contain only a single cell are known as unicellular organisms.
● Multicellular organisms are those which contain two or more than two cell
● The most important and fundamental level in the organisation of living world is
the cellular level.
● Cell in latin mean “ little room”
● First dead cell was observed and discovered by Robert Hooke in 1665 while
observing bark of the tree
● First living cell was discovered by Anton Ven Leeuwenhoek in pond water in 1674
● In 1831, A Scottish botanist, ROBERT BROWN discovered and name the nucleus
in plant cell
● HAECKEL established that the nucleus was responsible for storing and
transmitting hereditary characters
● CELL THEORY In 1838 , Jakob Matthias Schledien and theodor Schwann in 1839
, independently asserted that all animals and plants are made up of cells.
● The cell theory was redefined in 1855, when another German biologist,R. Virchow
presented the idea that all cells arise from pre-existing cells.
● Light microscope is a type of microscope which uses glass lenses, uses a beam
of light to illuminate the object and in which internal vacuum is not required
, ● Electron microscope is a type of microscope which uses electron
magnets,uses a beam of electron instead of light to illuminate the object,
and internal vacuum is essential.
● DNA - deoxyribonucleic acid
● RNA - ribonucleic acid
● GENE - it is a distinct unit of hereditary information .gene is inherited from
one generation to next and determines an observable characteristics , or
trait of an organism
● Prokaryotic cell - The form of cell composing many primitive unicellular
organisms, such as bacteria. Prokaryotic cells do not have nuclei, which are
partitioned by an intracellular membrane; instead the DNA forms one main coil in
the cell cytoplasm.
● Eukaryotic cell -A eukaryotic cell contains membrane-bound organelles
such as a nucleus, mitochondria ,and an endoplasmic reticulum.
Organisms based on the eukaryotic cell include protozoa,fungi, plants,
and animals. These organisms are grouped into the biological domain
Eukaryota. Eukaryotic cells are larger and more complex than
prokaryotic cells found in domains Archaea and Bacteria .
● Nucleus is a dense organelle present in most eukaryotic cells, typically a
single rounded structure bounded by a double membrane, containing the
genetic material.
● Nucleoid The nucleoid (meaning nucleus-like) is an irregularly shaped
region within the prokaryotic cell that contains all or most of the genetic
material.
● Each cell has got certain specific components within it known as cell
organelles.
● Plasma membrane is the outer most covering of the cell. Inside it lies the
cytoplasm. Plasma membrane is also known as selectively permeable
membrane because it allows some selective material to enter through it.
● In 1972,SINGER and NICOLSON suggested a model called fluid mosaic
model
●
9TH GRADE
BIOLOGY CHEAT SHEET
___
Notes
CELL
● All living bodies are made up of cells
● Organisms that contain only a single cell are known as unicellular organisms.
● Multicellular organisms are those which contain two or more than two cell
● The most important and fundamental level in the organisation of living world is
the cellular level.
● Cell in latin mean “ little room”
● First dead cell was observed and discovered by Robert Hooke in 1665 while
observing bark of the tree
● First living cell was discovered by Anton Ven Leeuwenhoek in pond water in 1674
● In 1831, A Scottish botanist, ROBERT BROWN discovered and name the nucleus
in plant cell
● HAECKEL established that the nucleus was responsible for storing and
transmitting hereditary characters
● CELL THEORY In 1838 , Jakob Matthias Schledien and theodor Schwann in 1839
, independently asserted that all animals and plants are made up of cells.
● The cell theory was redefined in 1855, when another German biologist,R. Virchow
presented the idea that all cells arise from pre-existing cells.
● Light microscope is a type of microscope which uses glass lenses, uses a beam
of light to illuminate the object and in which internal vacuum is not required
, ● Electron microscope is a type of microscope which uses electron
magnets,uses a beam of electron instead of light to illuminate the object,
and internal vacuum is essential.
● DNA - deoxyribonucleic acid
● RNA - ribonucleic acid
● GENE - it is a distinct unit of hereditary information .gene is inherited from
one generation to next and determines an observable characteristics , or
trait of an organism
● Prokaryotic cell - The form of cell composing many primitive unicellular
organisms, such as bacteria. Prokaryotic cells do not have nuclei, which are
partitioned by an intracellular membrane; instead the DNA forms one main coil in
the cell cytoplasm.
● Eukaryotic cell -A eukaryotic cell contains membrane-bound organelles
such as a nucleus, mitochondria ,and an endoplasmic reticulum.
Organisms based on the eukaryotic cell include protozoa,fungi, plants,
and animals. These organisms are grouped into the biological domain
Eukaryota. Eukaryotic cells are larger and more complex than
prokaryotic cells found in domains Archaea and Bacteria .
● Nucleus is a dense organelle present in most eukaryotic cells, typically a
single rounded structure bounded by a double membrane, containing the
genetic material.
● Nucleoid The nucleoid (meaning nucleus-like) is an irregularly shaped
region within the prokaryotic cell that contains all or most of the genetic
material.
● Each cell has got certain specific components within it known as cell
organelles.
● Plasma membrane is the outer most covering of the cell. Inside it lies the
cytoplasm. Plasma membrane is also known as selectively permeable
membrane because it allows some selective material to enter through it.
● In 1972,SINGER and NICOLSON suggested a model called fluid mosaic
model
●
