2. Kingdom Fungi (Fungus)
is a member of a large group of eukaryotic organisms
that includes microorganisms such as yeasts and molds
These organisms are classified as a kingdom, Fungi,
which is separate from plants, animals, and bacteria
One major difference is that fungal cells have cell walls
that contain chitin, unlike the cell walls of plants, which
contain cellulose.
These and other differences show that the fungi form a
single group of related organisms, named the Eumycota
(true fungi or Eumycetes), that share a common
ancestor (a monophyletic group).
3. Characteristics Fungi
With other eukaryotes: As other eukaryotes, fungal cells
contain membrane-bound nuclei with chromosomes that
contain DNA with noncoding regions called introns and
coding regions called exons.
With animals: Fungi lack chloroplasts and are
heterotrophic organisms, requiring preformed organic
compounds as energy sources.
With plants: Fungi possess a cell wall and vacuoles.
They reproduce by both sexual and asexual means, and
like basal plant groups (such as ferns and mosses)
produce spores. Similar to mosses and algae, fungi
typically have haploid nuclei.
4. Reproduction Fungi
Fungal reproduction is complex, reflecting the
differences in lifestyles and genetic makeup within this
kingdom of organisms.
It is estimated that a third of all fungi reproduce by
different modes of propagation; for example,
reproduction may occur in two well-differentiated stages
within the life cycle of a species, the teleomorph and the
anamorph.
Environmental conditions trigger genetically determined
developmental states that lead to the creation of
specialized structures for sexual or asexual reproduction
These structures aid reproduction by efficiently
dispersing spores or spore-containing propagules.
5. Growth and physiology Fungi
The growth of fungi as hyphae on or in solid substrates
or as single cells in aquatic environments is adapted for
the efficient extraction of nutrients, because these
growth forms have high surface area to volume ratios.
Hyphae are specifically adapted for growth on solid
surfaces, and to invade substrates and tissues.
They can exert large penetrative mechanical forces; for
example, the plant pathogen Magnaporthe grisea forms
a structure called an appressorium which evolved to
puncture plant tissues.
Traditionally, the fungi are considered heterotrophs,
organisms that rely solely on carbon fixed by other
organisms for metabolism.
Fungi have evolved a high degree of metabolic versatility
that allows them to use a diverse range of organic
substrates for growth, including simple compounds such
as nitrate, ammonia, acetate, or ethanol.
6. Taxonomy Fungi
The taxonomy of the Fungi is in a state of constant flux,
especially due to recent research based on DNA
comparisons.
These current phylogenetic analyses often overturn
classifications based on older and sometimes less
discriminative methods based on morphological features
and biological species concepts obtained from
experimental matings.
There is no unique generally accepted system at the
higher taxonomic levels and there are frequent name
changes at every level, from species upwards
7. Animal Cells
Animal cells are typical of the eukaryotic cell, enclosed
by a plasma membrane and containing a membrane-
bound nucleus and organelles.
Unlike the cells of the two other eukaryotic kingdoms,
plants and fungi, animal cells don't have a cell wall. This
feature was lost in the distant past by the single-celled
organisms that gave rise to the kingdom Animalia.
The lack of a rigid cell wall allowed animals to develop a
greater diversity of cell types, tissues, and organs.
Specialized cells that formed nerves and muscles --
tissues impossible for plants to evolve -- gave these
organisms mobility. The ability to move about by the use
of specialized muscle tissues is the hallmark of the
animal world. (Protozoans locomote, but by nonmuscular
means, i.e. cilia, flagella, pseudopodia.)
9. Centrioles - Centrioles are self-replicating organelles
made up of nine bundles of microtubules and are found
only in animal cells. They appear to help in organizing
cell division, but aren't essential to the process.
Golgi Apparatus - The Golgi apparatus is the distribution
and shipping department for the cell's chemical products.
It modifies proteins and fats built in the endoplasmic
reticulum and prepares them for export to the outside of
the cell.
Lysosomes - The main function of these microbodies is
digestion. Lysosomes break down cellular waste
products and debris from outside the cell into simple
compounds, which are transferred to the cytoplasm as
new cell-building materials.
Nucleus - The nucleus is a highly specialized organelle
that serves as the information and administrative center
of the cell.
10. Mitochondria - Mitochondria are oblong shaped
organelles that are found in the cytoplasm of every
eukaryotic cell. In the animal cell, they are the main
power generators, converting oxygen and nutrients into
energy.
Microtubules - These straight, hollow cylinders,
composed of tubulin protein, are found throughout the
cytoplasm of all eukaryotic cells and perform a number
of functions.
Microfilaments - Microfilaments are solid rods made of
globular proteins called actin. These filaments are
primarily structural in function and are an important
component of the cytoskeleton.
Cilia and Flagella - For single-celled eukaryotes, cilia
and flagella are essential for the locomotion of individual
organisms. In multicellular organisms, cilia function to
move fluid or materials past an immobile cell as well as
moving a cell or group of cells.
11. Peroxisomes - Microbodies are a diverse group of
organelles that are found in the cytoplasm, roughly
spherical and bound by a single membrane. There are
several types of microbodies but peroxisomes are the
most common.
Plasma Membrane - All living cells have a plasma
membrane that encloses their contents. In prokaryotes,
the membrane is the inner layer of protection surrounded
by a rigid cell wall. Eukaryotic animal cells have only the
membrane to contain and protect their contents. These
membranes also regulate the passage of molecules in
and out of the cells.
Ribosomes - All living cells contain ribosomes, tiny
organelles composed of approximately 60 percent RNA
and 40 percent protein. In eukaryotes, ribosomes are
made of four strands of RNA. In prokaryotes, they
consist of three strands of RNA.
12. PLANT CELL
A large central vacuole, a water-filled volume
enclosed by a membrane known as the tonoplast
maintains the cell's turgor, controls movement of
molecules between the cytosol and sap, stores
useful material and digests waste proteins and
organelles.
A cell wall composed of cellulose and
hemicellulose, pectin and in many cases lignin, are
secreted by the protoplast on the outside of the cell
membrane. This contrasts with the cell walls of fungi
(which are made of chitin), and of bacteria, which
are made of peptidoglycan.
Specialised cell-cell communication pathways
known as plasmodesmata , pores in the primary cell
wall through which the plasmalemma and
endoplasmic reticulum of adjacent cells are
continuous.
14. amyloplast - an organelle in some plant cells that stores
starch. Amyloplasts are found in starchy plants like
tubers and fruits.
ATP - ATP is short for adenosine triphosphate; it is a
high-energy molecule used for energy storage by
organisms. In plant cells, ATP is produced in the cristae
of mitochondria and chloroplasts.
cell membrane - the thin layer of protein and fat that
surrounds the cell, but is inside the cell wall. The cell
membrane is semipermeable, allowing some substances
to pass into the cell and blocking others.
cell wall - a thick, rigid membrane that surrounds a plant
cell. This layer of cellulose fiber gives the cell most of its
support and structure. The cell wall also bonds with other
cell walls to form the structure of the plant.
15. centrosome - (also called the "microtubule organizing
center") a small body located near the nucleus - it has a
dense center and radiating tubules. The centrosomes is
where microtubules are made. During cell division
(mitosis), the centrosome divides and the two parts
move to opposite sides of the dividing cell. Unlike the
centrosomes in animal cells, plant cell centrosomes do
not have centrioles.
chlorophyll - chlorophyll is a molecule that can use light
energy from sunlight to turn water and carbon dioxide
gas into sugar and oxygen (this process is called
photosynthesis). Chlorophyll is magnesium based and is
usually green.
chloroplast - an elongated or disc-shaped organelle
containing chlorophyll. Photosynthesis (in which energy
from sunlight is converted into chemical energy - food)
takes place in the chloroplasts.
16. christae - (singular crista) the multiply-folded inner membrane
of a cell's mitochondrion that are finger-like projections. The
walls of the cristae are the site of the cell's energy production
(it is where ATP is generated).
cytoplasm - the jellylike material outside the cell nucleus in
which the organelles are located.
Golgi body - (also called the golgi apparatus or golgi complex)
a flattened, layered, sac-like organelle that looks like a stack
of pancakes and is located near the nucleus. The golgi body
packages proteins and carbohydrates into membrane-bound
vesicles for "export" from the cell.
granum - (plural grana) A stack of thylakoid disks within the
chloroplast is called a granum.
mitochondrion - spherical to rod-shaped organelles with a
double membrane. The inner membrane is infolded many
times, forming a series of projections (called cristae). The
mitochondrion converts the energy stored in glucose into ATP
(adenosine triphosphate) for the cell.
nuclear membrane - the membrane that surrounds the
nucleus.
17. nucleolus - an organelle within the nucleus - it is where
ribosomal RNA is produced.
nucleus - spherical body containing many organelles,
including the nucleolus. The nucleus controls many of
the functions of the cell (by controlling protein synthesis)
and contains DNA (in chromosomes). The nucleus is
surrounded by the nuclear membrane.
photosynthesis - a process in which plants convert
sunlight, water, and carbon dioxide into food energy
(sugars and starches), oxygen and water. Chlorophyll or
closely-related pigments (substances that color the
plant) are essential to the photosynthetic process.
ribosome - small organelles composed of RNA-rich
cytoplasmic granules that are sites of protein synthesis.
18. rough endoplasmic reticulum - (rough ER) a vast system of
interconnected, membranous, infolded and convoluted sacks that
are located in the cell's cytoplasm (the ER is continuous with the
outer nuclear membrane). Rough ER is covered with ribosomes that
give it a rough appearance. Rough ER transport materials through
the cell and produces proteins in sacks called cisternae (which are
sent to the Golgi body, or inserted into the cell membrane).
smooth endoplasmic reticulum - (smooth ER) a vast system of
interconnected, membranous, infolded and convoluted tubes that
are located in the cell's cytoplasm (the ER is continuous with the
outer nuclear membrane). The space within the ER is called the ER
lumen. Smooth ER transport materials through the cell. It contains
enzymes and produces and digests lipids (fats) and membrane
proteins; smooth ER buds off from rough ER, moving the newly-
made proteins and lipids to the Golgi body and membranes
stroma - part of the chloroplasts in plant cells, located within the
inner membrane of chloroplasts, between the grana.
19. thylakoid disk - thylakoid disks are disk-shaped
membrane structures in chloroplasts that contain
chlorophyll. Chloroplasts are made up of stacks
of thylakoid disks; a stack of thylakoid disks is
called a granum. Photosynthesis (the production
of ATP molecules from sunlight) takes place on
thylakoid disks.
vacuole - a large, membrane-bound space
within a plant cell that is filled with fluid. Most
plant cells have a single vacuole that takes up
much of the cell. It helps maintain the shape of
the cell.
