Cell
Tissue
Organ
Organ system
Organism
Levels of organization in an organism
Genetic materials
(Characteristic of life) All living organisms store hereditary information in the form of nucleic acid molecules, such as DNA or RNA.
Response to stimuli
(Characteristic of life) Also known as "sensitivity.” Living organisms can react/respond to the several factors present in the environment. Examples of this are light, pressure, odor, pressure, temperature, and humidity.
Growth and development
(Characteristic of life) Organisms grow and develop according to specific instructions coded for by their genes.
These genes provide instructions that will direct cellular growth and development, ensuring that a species’ young will grow up to exhibit many of the same characteristics as its parents.
Growth
refers to the increase in mass and size of a body or organs. It typically occurs through the multiplication of cells and an increase in intracellular substance.
Development
refers to the physiological and functional maturation of the organism.
Reproduction
(Characteristic of life) Occurs when DNA containing genes are passed along to an organism’s offspring.
Single-celled organisms reproduce by first duplicating their DNA, which is the genetic material, and then dividing it equally as the cell prepares to divide to form two new cells. Many multicellular organisms produce specialized reproductive cells that will form new individuals.
Eukaryotes
Which undergoes sexual reproduction?
Prokaryotes
Which undergoes asexual reproduction?
Homeostasis
(Characteristic of life) Organisms are able to maintain internal conditions within a narrow range almost constantly, despite environmental changes, through a process called ______________ or “steady state.”
Homeostasis
the ability of an organism to maintain constant internal conditions. It is an important function in all humans and animals as keeping a stable environment requires constant adjustments as the environment changes.
Adaptation
(Characteristic of life) All living organisms exhibit a “fit” to their environment. It is a consequence of evolution by natural selection, which operates in every lineage of reproducing organisms.
Metabolism
(Characteristic of life) All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy in food; others use chemical energy from molecules they take in.
Cells
are the smallest common denominator of life.
Unicellular
Living things that are made of only one cell only, such as bacteria and protozoa, are called ________ organisms.
Multicellular
Living things made up of many cells, such as plants and animals, are called __________ organisms.
Microscope
is an instrument that is used to magnify small objects.
Romans
Before the invention of the microscope was invented, the ________ had already invented and experimented with glasses during the first century (year 100).
One of these glass samples involved a piece that had thick middle and thin edges.
Lens
is derived from the Latin word lentil because it closely resembled the shape of the lentil bean.
Zacharias and Hans Jansen
Developed the first compound microscope which consists of at least two lenses in 1590 by these Dutch spectacle-makers.
Robert Hooke
In 1665, he examined a thin slice of cork under the microscope that he built. He was able to see and observe small compartments of the cork. He initially named the small compartments "cellula" because they reminded him of the little rooms in the monastery. These eventually became known as cells.
Antoine Van Leeuwenhoek
His microscopes consisted of a small glass ball set inside a metal frame. He became known for using his microscopes to observe freshwater single-celled microorganisms that he called “animalcules.”
Robert Brown
In 1830, he identified a darkly staining structure at the center of every cell he observed. He referred to such a structure as the nucleus.
Mathias Schleiden
(Cell theory) In 1838, a German botanist proposed as a result of his experiments that all plants are made up of cells.
Theodor Schwann
(Cell theory) A year later, a German physiologist, observed and proposed that all animals are, likewise, made up of cells.
Rudolf Virchow
(Cell theory) In 1858, a German pathologist, concluded that cells reproduce by forming new cells.
Cell theory
states that:
All organisms are composed of one or more cells.
The cell is the basic unit structure and function of all organisms.
All cells arise from pre-existing cells.
It tell us that the cell is the basic structural, functional, and reproductive unit of all organisms. It also provides us with an operational definition of "life.”
Spontaneous generation
is an incorrect and obsolete hypothesis about the possibility of life forms being able to emerge from non-living things; it was generally accepted until the 19th century.
Aristotle
The theory of spontaneous generation was first comprehensively posited by ________ in his book ”On the Generation of Animals.”
The theory of spontaneous generation
a theory that aims to explain the seemingly sudden emergence of organisms such as rats, flies, and maggots within rotting meat and other decomposable items.
The theory suggests that organisms do not descend from other organisms or from a parent, and only require that certain conditions in their environment be fulfilled in order for creation to occur.
Pneuma
Aristotle theorized that non-living matter contained a “vital heat” called _______.
Francesco Redi
was an Italian physician and the first scientist to suspect that the theory of spontaneous generation may be flawed.
Francesco Redi
He placed fresh meat into two different jars, one with a muslin cloth over the top, and the other left open. A few days later, the open jar contained maggots, while the covered container did not. He saw this as proof that maggots had to come from fly eggs and could not spontaneously generate.
John Needham
an English naturalist and an avid supporter of spontaneous generation theory, performed an experiment in which he boiled up a broth and poured it into a covered flask.
Lazzaro Spallanzani
Another Italian scientist who performed a similar experiment to Needham and found that if the broth was heated after the flask was sealed rather than before, the organisms did not generate. He decided that Needham’s broths had been contaminated between the boiling pan and the flask.
Needham’s response claimed that air was necessary for spontaneous generation and that the “vital heat” in the air had been destroyed during _______’s experiment.
Louis Pasteur
a French scientist named ________ designed a series of flasks with the necks bent into an S shape. The necks were fashioned so that fresh air could reach the flasks but were bent in such a way that any air-borne microbes would be trapped at the bottom of the curves.
Lens
Before the invention of the microscope, what instrument did the Romans use to magnify small object?
Antoine Van Leeuwenhoek
Who used this microscope?
Organelles
The cell contains different parts called:
Eukaryotic
______ cells are generally larger and have very distinct nuclei that are clearly surrounded by nuclear membranes. They also have numerous membrane-bound organelles found in the cytoplasm. Protists, plants, fungi and animals are examples.
Prokaryotic
_____ lack a nuclear envelope and membrane -bound organelles, an example of which is the bacterial cell. Bacterial cells are small, about 0.2 to 5μm (micrometer), less complex, usually exist in unicellular forms and have limited capabilities.
Capsule
(Organelles of prokaryotic cells)
a sticky outer layer that provides protection.
Cell wall
(Organelles of prokaryotic cells)
a structure that confers rigidity and shape to the cell.
Plasma membrane
(Organelles of prokaryotic cells)
a structure that serves as a permeability barrier.
Plasmid
(Organelles of prokaryotic cells)
a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium.
Nucleoid
(Organelles of prokaryotic cells)
a DNA-containing region with cytoplasm.
Cytoplasm
(Organelles of prokaryotic cells)
the region where all cytoplasmic organelles are found.
Ribosome
(Organelles of prokaryotic cells)
the site where protein is synthesized.
Pilus or Pili
(Organelles of prokaryotic cells)
a hair-like appendage that functions in adhesion
Flagellum
(Organelles of prokaryotic cells)
facilitates movement of bacteria.
Cell membrane
(Organelles of eukaryotic cells)
is a double-layered membrane that encloses the cell. It is made up of 2 layers of phospholipids with proteins and carbohydrates scattered outside, within, and inside the bilipid layer like a mosaic.
also known as plasma membrane or plasmalemma.
Cell membrane
(Organelles of eukaryotic cells) It functions as:
the boundary between the cell and its external environment
a structure that controls the movement of substances in and out of the cell (because it is a semipermeable membrane, it allows the entry of some substances, such as water, and prevents the entry of others).
It is very flexible, allowing the cell to change its shape when needed. The proteins found in the _________ are important for the cell to communicate with its neighbors (cell to cell interaction).
Cytoplasm
(Organelles of eukaryotic cells)
Inside the cell membrane and surrounding the nucleus is a part of the protoplasm called ______.
forms the largest part of the cell where most life processes occur.
made up of a fluid-like substance where membrane-bound organelles (small structures inside the cell that carry specific functions) are located.
Mitochondria
(Organelles of eukaryotic cells)
small, double-membrane, spherical, or sausage-shaped organelles involved in the production of energy.
popularly known as the powerhouse of the cell.
the energy it produces is important for cells’ activities, such as growth and reproduction.
also contains its own DNA and RNA and is capable of producing its protein. It is, therefore, capable of division to produce more of itself.
Adenosine triphosphate
The mitochondria also produces ATP, which is:
Endoplasmic reticulum
(Organelles of eukaryotic cells)
is a network of intercommunicating channels in the cytoplasm. It is composed of membrane-enclosed sacs and tubules. It has 2 kinds.
Rough endoplasmic reticulum
(Organelles of eukaryotic cells)
most common type of ER described as such due to the presence of ribosomes (where protein is synthesized) on its membrane surface, giving it a "rough" appearance.
appears grainy.
plays a role in the production of protein, as well as in its folding, quality control and dispatch.
Smooth endoplasmic reticulum
(Organelles of eukaryotic cells)
a more tubular non-granular structure due to the absence of ribosomes.
plays a role in the manufacture and metabolism of lipids (steroids)
plays a role in the biosynthesis of steroid hormones in endocrine cells.
transports macromolecules.
where detoxification of drugs/poison occurs.
Golgi Apparatus
(Organelles of eukaryotic cells)
composed of sets of cisternae (piles of flattened sacs) and numerous vesicles filled with fluid and suspended substances.
responsible for the processing, packaging, and sorting of secretory materials for use within and outside the cell.
where proteins go for more preparation after the ER.
fluid-filled sacs
a membranous pouch, that buds off from the smooth ER, then migrates and fuses.
Lysosomes
(Organelles of eukaryotic cells)
small, spherical, membrane-bound organelles that contain a number of enzymes for intracellular digestion (which contain hydrolytic enzymes)
is bounded by a single-layered membrane.
contains around 40 kinds of enzymes that help digest food, disease-causing bacteria engulfed by WBCs, and worn-out and broken parts of the cell.
exclusive organelle for animal cells.
“suicide bag/sack” of cells
recycles intracellular materials via autophagy.
Cytoplasmic Inclusions
(Organelles of eukaryotic cells)
are non-membranous substances and structures suspended in the cytoplasm with varying functions. Their presence or absence depends on the cell type (although ribosomes are present in all cells.)
Ribosome
(Organelles of eukaryotic cells)
small granular structures made up of RNA and proteins.
involved in the production of proteins in a process called protein synthesis.
composed of large and small subunits that are tightly bound to each other.
Centriole
(Organelles of eukaryotic cells)
has a central role in cell division where it participates in the formation of the mitotic spindle.
usually adjacent to the nucleus.
Its wall is composed of 9 groups of parallel subunits arranged in a longitudinal fashion. Each of the 9 groups consists 3 microtubules aligned and fused together so that they appear as 3 circles in a row.
Cytoskeleton
(Organelles of eukaryotic cells)
a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement.
maintains cell structure.
Chloroplast
only in plant cells.
site for food production and other photosynthetic organisms.
Red blood cells
have a biconcave disc shape and are highly deformable.
allows for easy movement through blood vessels, which can be as small as 2 to 3 micrometers in diameter.
losing the nucleus increases the surface area for gas exchange, thus, enabling optimal oxygenation of tissues in the body.
Sperm cell
have a tail called the flagellum, which propels it toward the egg cell for fertilization.
have plenty of mitochondria along with their middle piece, which powers the flagellum to move the sperm cells toward the egg cell.
Root hair cells
Its function is to obtain water from the ground and transport this to the Xylem. Plants absorb water from the soil by osmosis.
_______ are adapted for this by having a large surface area to speed up osmosis.
have a large permanent vacuole that speeds up the movement of water by osmosis. The water which enters the ________ then travels up the Xylem and travels to the leaves.
Nerve cells
mostly elongated
facilitate the transmission of impulses from the brain and the spinal cord to the different parts of the body.
Tracheal cells
have cilia that beat and drive air impurities or foreign particles and mucus secretion up the trachea to the mouth where they can be coughed out.
Cell-cell junctions
Another specialized modification observed in multicellular cells is the __________________, the points where two cells come together. Through this, the cells are joined in long-term associations, forming tissues and organs.
Living things
Cells are the building blocks of:
Prokaryote
Which type of cell has no nucleus?
Cell wall
A rigid structure that protects and provides support to the plant cell.
Chloroplast
An organelle that takes in sunlight energy, carbon dioxide, and water to make food.
Energy
What does the chloroplast help make for the plant?
Ribosomes
An organelle that builds proteins:
Nucleus
An organelle that directs all cell activities and stores DNA.
Cell membrane
This structure allows materials to enter and exit the cell.
Chloroplast, cell wall
These structures are found in plant cells only.
Cytoplasm
A fluid that fills the cell and holds the organelles in place.
Nucleus
Which is most likely to be found in both a spinach cell and a muscle cell?
Vacuoles
Cells store water and other substances in which organelles?
Golgi apparatus
is a vital organelle responsible for processing proteins and packaging them for transport, such as enzymes, hormones, and receptors.
Plasma membrane
acts as a permeability barrier between the cell and its external environment, ensuring that the proteins reach their intended destinations within the cell.
Rough
the _______ ER consists of ribosomes attached to it and serves as a site for protein synthesis and modification.
Smooth
the _______ ER synthesizes lipid and steroid hormones and lacks ribosomes.
Fluid mosaic model
The most acceptable cell membrane today is the ___________, first proposed by Seymour Jonathan Singer and Garth L. Nicolson in 1972 to describe the structure of cell membranes.
Phospholipids
Cholesterol
Proteins
Carbohydrates
What are the major components of the cell membrane?
Phospholipids
(Component of plasma membrane)
make up the majority of the cell membrane.
Cholesterol
(Component of plasma membrane)
found in between the phospholipids and acts as a fluidity buffer.
Helps maintain the fluidity of the cell membrane and structure of the cell.
Adds firmness to the plasma membrane.
Proteins
(Component of plasma membrane)
can be found on the surface or embedded across the cell membrane and involved in the transport of materials in and out of the cell membrane.
the second major component.
Carbohydrates
(Component of plasma membrane)
generally attached to proteins and lipids on the surface of the cell membrane.
Plasma membrane
FLUIDITY.
selectively permeable; allows molecules and prevents others to enter/exit freely.
structure and components must be very flexible to allow cells (RBCs, WBCs) to change shape to pass through narrow capillaries.
Phospholipids
has a hydrophilic head and two hydrophobic tails.
The hydrophilic head group has a phosphate-containing group attached to a glycerol molecule.
The hydrophobic tails, each containing either a saturated or an unsaturated fatty acid, are long hydrocarbon chains.
form an excellent lipid bilayer cell membrane that separates fluid within the cell from the fluid outside of the cell.
Peripheral proteins
Type of protein:
loosely bound to the surface of the membrane
cell surface identity marker (antigen)
Integral proteins
Type of protein:
penetrate lipid bilayer
transport proteins
Carbohydrates
the third major component of the cell membrane
The extracellular surface of the cell membrane is decorated with ____________ groups attached to lipids and proteins.
play a key role in cell-cell recognition.
Glycolipid
a molecule that has one or more carbohydrate units covalently bonded to it and an essential part of the cell membrane.
acts as receptors at the surface of the RBC and also helps determine the blood group of an individual.
some microorganisms use __________ on their cell surface as well. This helps the immune system destroy pathogens from the body.
cell recognition
Glycoprotein
a molecule that has one or more carbohydrate units covalently bonded to it.
identifies the cell type and allows it to bind with other cells of the same type.
repel other cell types and other particles.