Transcript Protists Abdulhafez A Selim, MD, PhD

Protists
Abdulhafez A Selim, MD, PhD
[email protected]
Protists
Protozoa
Algae
Fungus-Like Protists
Simple “Eukaryotic” Organisms.
 Unicellular.
 Live in aquatic environments.

Protists; cellular structure
Single
Cell
Colony
Multicelluar organism
coenocytes
Protists; feeding methods
Protists
Autotrophic
Heterotrophic
Protists; feeding methods

An autotroph (from the
Greek autos = self and
trophe = nutrition) is an
organism that produces
organic compounds from
carbon dioxide as a
carbon source, using
either light or reactions of
inorganic chemical
compounds, as a source
of energy. An autotroph is
known as a producer in
a food chain.

A heterotroph (Greek
heterone = (an)other and
trophe = nutrition) is an
organism that requires
organic substrates to get
its carbon for growth and
development. A
heterotroph is known as a
consumer in the food
chain.
Autotroph or heterotroph?
Protists, how they live?
Protists
Free living
Symbiotic
Symbiosis

Symbiosis (pl. symbioses)(from the Greek words syn =
with/plus and bio = life) is an interaction between two
organisms living together in more or less intimate
association or even the merging of two dissimilar
organisms that bond and interact as a living element.
The term host is usually used for the larger (macro) of
the two members of a symbiosis. The smaller (micro)
member is called the symbiont (plural: symbionts), or
alternately, symbiote (plural: symbiotes). When a
microscopic symbiont lives inside the cells of a host, it is
referred to as an endosymbiont.
Protists, reproduction.
Protists reproduction
Sexually
Asexually
Protists, movement
Protists
Motile
Cilia, Flagella or
Pseudopodia
Non-motile
Few
Protists, movement
A cilium (plural cilia) or
undulipodium (pl.:
undulipodia) is an
organelle found in
eukaryotic cells. Cilia are
thin, tail-like projections
extending approximately
5-10 micrometers
outwards from the cell
body. There are two
types of cilia: motile cilia,
which constantly beat in
one direction, and nonmotile cilia, which
typically serve as
sensory organelles.
A flagellum (plural,
flagella) is a long, whip
like projection
composed by
microtubes. They help
propel cells and
organisms in a whip like
motion. The flagellum of
eukaryotes usually
moves with an “S”
motion, and is
surrounded by cell
membrane.
Pseudopods or
pseudopodia (false
feet) are temporary
projections of
eukaryotic cells.
Cells having this
faculty are generally
referred to as
amoeboids.
Phylogenetic relationship
How it was determined?
 Ultrastructure (electron microscopy cell
structure)
 Molecular data (DNA sequence similarity)

Protists DNA Bar code
Protists
Protozoa
Algae
Fungus-Like Protists
Protozoa
Amoebas
Amoebic
Dysentery
Forams
Index fossils
Actinopods
Zooflagellates
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Ciliates
Apicomplexans
Plasmodium;
Malaria
Protists, Protozoa, Amoeba
Amoebic dysentery

Amoebic dysentery is transmitted by
contaminated water, and is well known as a
"traveler's dysentery" because of its prevalence
in developing nations, although it is occasionally
seen in industrialized countries. Liver infection,
and subsequent amoebic abscesses can occur.
It can be treated with metronidazole or related
azole drugs.
Protists, Protozoa, Forams
The Foraminifera, or forams for short, are a large group of
amoeboid protists with reticulating pseudopods, fine strands that
branch and merge to form a dynamic net.
Psuedopods
They typically produce a shell, or test, which can have either
one or multiple chambers, some becoming quite elaborate in
structure.
About 250,000 species are recognized, both living and fossil.
They are usually less than 1 mm in size, but some are much
larger, and the largest recorded specimen reached 19 cm.
fossil
The form and composition of the test is the primary means
by which forams are identified and classified. Most have
calcareous tests, composed of calcium carbonate, which
generally takes the form of interlocking microscopic crystals,
giving it a glassy or hyaline appearance.
Openings in the test, including those that allow cytoplasm to
flow between chambers, are called apertures.
Uses of Forams

Because of their diversity, abundance, and complex morphology, fossil foraminiferal assemblages are useful for
biostratigraphy, and can accurately give relative dates to rocks.

Before more modern techniques became available, the
as forams to find potential oil deposits.

Calcareous fossil foraminifera are formed from elements found in the ancient seas they lived in. Thus they are
very useful in paleoclimatology and paleoceanography.

They can be used to reconstruct past climate by examining the
oil industry relied heavily on microfossils such
stable isotope ratios of oxygen; The
ratio
of 18O to 16O is used to tell the temperature of the surrounding water of the time solidified, indirectly.

Geographic patterns seen in the fossil records of planktonic forams are also used to reconstruct ancient
ocean
currents.

Because certain types of foraminifera are found only in certain environments, they can be used to figure out the
kind of environment under which ancient marine sediments were deposited.

For the same reasons they make useful biostratigraphic markers, living foraminiferal assemblages have been used
as bioindicators in coastal environments, including indicators of coral reef health.

Because calcium carbonate is subsceptible to dissolving in acidic conditions, Foraminifera may be particularly
affected by changing climate and ocean acidification.
Ocean currents
Protists, Protozoa, Actinopods

Radiolarians have many needlelike pseudopods supported by
bundles of microtubules, called
axopods, which aid in flotation.

The nuclei and most other
organelles are in the endoplasm,
while the ectoplasm is filled with
frothy vacuoles and lipid droplets,
keeping them buoyant.

Often it also contains symbiotic
algae, especially zooxanthellae,
which provide most of the cell's
energy.
Actinopods, Radiolarians, Ecology

Radiolarians They are found as plankton
throughout the ocean, and because of
their rapid turn-over of species, their tests
are important diagnostic fossils
zooflagellates
ZAAACF
Protozoa
Protists
Protozoa
Algae
Amoebas
Forams
Actinopods
Zooflagellates
Amoebic
Dysentery
Index fossils
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Ciliates
Apicomplexans
Fungus-Like Protists
Plasmodium;
Malaria
Protists, Protozoa,
Zooflagellates; Trypanosoma

Trypanosoma is a notable genus of trypanosomes, a monophyletic[1] group of
unicellular parasitic protozoa.

The name is derived from the Greek trypaô (boring) and soma (body) because of the
way the organisms move.

Different species infect a variety of different vertebrates, including humans, causing
the trypanosomiasis diseases, e.g. sleeping sickness.

Most species are transmitted by invertebrates such as biting insects.

Trypanosoma undergo a complex lifecycle which may include several different
morphological forms especially in the species which are transmitted by invertebrates.

They may go through a variety of different forms in the invertebrate host, but in the
vertebrate host the cells take a characteristic form called a trypomastigote, where the
flagellum is runs from the posterior to the anterior of the cell and is connected by an
undulating membrane.
Trypanosoma Life Cycle
Protists, Protozoa, Zooflagellates;
Giardia, Giardiasis

Giardia lamblia (formerly also Lamblia
intestinalis and also known as Giardia
duodenalis and Giardia intestinalis) is a
flagellated protozoan parasite that infects
the gastrointestinal tract and causes
giardiasis.

Infection causes giardiasis, a type of
gastroenteritis that manifests itself with
severe diarrhea and abdominal cramps.
Other symptoms can include bloating,
flatulence, fatigue, nausea, vomiting and
weight loss. In some patients, vomiting or
nausea is the major symptom. The
symptoms usually manifest themselves
about seven to ten days after ingestion.
Giardia is a major cause of intestinal
disease worldwide and the most frequent
non-bacterial cause of diarrhea in North
America. Nonetheless, the basic biology of
this parasite is poorly understood.
Giardiasis, Prophylaxis
Filter use or boiling is recommended for
water purification of drinking water in
wilderness conditions.
 Treatment of drinking water for Giardia
typically involves some form of high
efficiency filtration and/or chemical
disinfection such as chlorination or
ozonation. Treatment is necessary
throughout North America.

Ciliates
Zooflagellates, choanoflagellates


The choanoflagellates are a
group of flagellate protozoa.

They are considered to be the
closest relatives of the animals,
and the last unicellular ancestors
of animals are thought to have
resembled modern
choanoflagellates.

Each choanoflagellate has a
single flagellum, surrounded by a
ring of hairlike protrusions called
microvilli, forming a cylindrical or
conical collar (choanos in Greek).
Ciliates, reproduction

Unlike other eukaryotes, ciliates have two different sorts of nuclei: a small,
diploid micronucleus (reproduction), and a large, polyploid macronucleus
(general cell regulation).

polyploid macronucleus is generated from the micronucleus by amplification
of the genome and heavy editing.

Division of the macronucleus occurs by amitosis, the segregation of the
chromosomes is by a process, whose mechanism is unknown.

This process is by no means perfect, and after about 200 generations the
cell shows signs of aging.

Periodically the macronuclei must be regenerated from the micronuclei. In
most, this occurs during sexual reproduction, which is not usually through
syngamy but through conjugation. Here two cells line up, the micronuclei
undergo meiosis, some of the haploid daughters are exchanged and then
fuse to form new micro- and macronuclei.
Protists, Algae
Protists
Protozoa
Algae
Fungus-Like Protists
Algae
Euglenoids
Create
green and opaque
water problems
in aquariums.
Diflagellates
Major producer in
marine ecosystems
Zooxanthellae;
toxic blooms
(Red tides)
Diatoms
Golden Algae
Brown Algae
Major component of
Ocean’s minute
plankton
Ecological importance
in cooler ocean water
Green Algae
Red Algae
Ecological importance
in tropical ocean
Reef building
Eugelnoids

The euglenids (also spelled euglenoids) are
one of the best-known groups of flagellates,
commonly found in freshwater especially
when it is rich in organic materials, with a
few marine and endosymbiotic members.

Many euglenids have chloroplasts and
produce energy through photosynthesis, but
others feed by phagocytosis or strictly by
osmosis.

Euglenids are distinguished mainly by the
presence of a pellicle, which is composed of
proteinaceous strips underneath the cell
membrane, supported by dorsal and ventral
microtubules. This varies from rigid to
flexible, and gives the cell its shape, often
giving it distinctive striations.
Eugelnoids

Euglena green algae can create green and
opaque water problems in aquariums.
Euglena can grow due to high Nitrate,
Phosphate levels or direct sunlight.
Decreasing phosphate and Nitrate by
patial water change and moving the
aquarium to shade can help in solving the
problem.
Dinoflagellates

The dinoflagellates are a large group of
flagellate protists.

Most are marine plankton, but they are
common in fresh water habitats as well;
their populations are distributed depending
on temperature, salinity, or depth.

About half of all dinoflagellates are
photosynthetic.

Being primary producers make them an
important part of the aquatic food chain.

Some species, called zooxanthellae, are
endosymbionts of marine animals and
protozoa, and play an important part in the
biology of coral reefs.

Other dinoflagellates are colorless
predators on other protozoa, and a few
forms are parasitic (see for example
Oodinium, Pfiesteria).
Dinoflagellates, Ecology

Dinoflagellates sometimes bloom in
concentrations of more than a million
cells per millilitre. Some species
produce neurotoxins, which in such
quantities kill fish and accumulate in
filter feeders such as shellfish, which in
turn may pass them on to people who
eat them. This phenomenon is called a
red tide, from the color the bloom
imparts to the water.

Some colorless dinoflagellates may
also form toxic blooms, such as
Pfiesteria.

It should be noted that not all
dinoflagellate blooms are dangerous.

Bluish flickers visible in ocean water at
night often come from blooms of
bioluminescent dinoflagellates, which
emit short flashes of light when
disturbed.
Dinoflagellates, Caution

Red Tide is more specifically produced when
dinoflagellates are able to reproduce rapidly and
copiously on account of the abundant nutrients in the
water.

Although the resulting red waves are a miraculous sight,
they, again, contain toxins that not only affect all marine
life in the ocean but the people who consume them as
well. A specific carrier is shellfish. This can introduce
both non-fatal and fatal illnesses.

Human inputs of phosphate further encourage these red
tides, and consequently there is a strong interest in
learning more about dinoflagellates, from both medical
and economic perspectives.
zooflagellates
ZAAACF
Protozoa
Protists
Protozoa
Algae
Amoebas
Forams
Actinopods
Zooflagellates
Amoebic
Dysentery
Index fossils
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Ciliates
Apicomplexans
Fungus-Like Protists
Plasmodium;
Malaria

The ookinetes penetrate and
escape the midgut, then embed
themselves onto the exterior of the
gut membrane. Here they divide
many times to produce large
numbers of tiny elongated
sporozoites.

These sporozoites migrate to the
salivary glands of the mosquito
where they are injected into the
blood of the next host the
mosquito bites. The sporozoites
move to the liver where they
repeat the cycle.
Plasmodium, Malaria

The life cycle of Plasmodium is very complex.
Sporozoites from the saliva of a biting female
mosquito are transmitted to either the blood or the
lymphatic system[1] of the recipient.

The sporozoites migrate to the liver and invade
hepatocytes. The so-called latent or dormant stage
of the Plasmodium sporozoite in the liver is called
the hypnozoite.

From the hepatocytes, the parasite replicates into
thousands of merozoites, which then invade red
blood cells. Here the parasite grows from a ringshaped form to a larger trophozoite form. In the
schizont stage, the parasite divides several times to
produce new merozoites, which leave the red blood
cells and travel within the bloodstream to invade
new red blood cells.

Most merozoites continue this replicative cycle, but
some merozoites differentiate into male or female
sexual forms (gametocytes) (also in the blood),
which are taken up by the female Anopheles
mosquito. In the mosquito's midgut, the
gametocytes develop into gametes and fertilize
each other, forming motile zygotes called ookinetes.
Malaria, Blood Picture
On a molecular level, the parasite damages
red blood cells using plasmepsin enzymes.
Plasmepsins are aspartic acid proteases which
degrade hemoglobin.
Summary
Protozoa
Protists
Protozoa
Algae
Amoebas
Forams
Actinopods
Zooflagellates
Amoebic
Dysentery
Index fossils
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Ciliates
Apicomplexans
Fungus-Like Protists
Plasmodium;
Malaria
Algae
Euglenoids
Create
green and opaque
water problems
in aquariums.
Diflagellates
Major producer in
marine ecosystems
Zooxanthellae;
toxic blooms
(Red tides)
Diatoms
Golden Algae
Brown Algae
Major component of
Ocean’s minute
plankton
Ecological importance
in cooler ocean water
Green Algae
Red Algae
Ecological importance
in tropical ocean
Reef building
Diatoms

Diatoms (Greek: διά (dia) = "through" +
τέμνειν (temnein) = "to cut", i.e., "cut in
half") are a major group of eukaryotic
algae, and are one of the most common
types of phytoplankton.

Most diatoms are unicellular, although
some form chains or simple colonies.

A characteristic feature of diatom cells is
that they are encased within a unique
cell wall made of silica.

These walls show a wide diversity in
form, some quite beautiful and ornate,
but usually consist of two symmetrical
sides with a split between them, hence
the group name.
Diatoms

The use of silicon by diatoms is believed by many researchers to be
the key to their ecological success.

In a new classic study, Egge & Aksnes (1992) found that diatom
dominance of mesocosm communities was directly related to the
availability of silicate. When silicon content approaches a
concentration of 2 mmol m-3, diatoms typically represent more than
70% of the phytoplankton community.

Raven (1983) noted that, relative to organic cell walls, silica frustules
require less energy to synthesize (approximately 8%), potentially a
significant saving on the overall cell energy budget.

Other researchers (Milligan & Morel, 2002) have suggested that the
biogenic silica in diatom cell walls acts as an effective pH buffer,
facilitating the conversion of bicarbonate to dissolved CO2 (which is
more readily assimilated).
Diatoms

Planktonic forms in freshwater and marine environments typically exhibit a "bloom and bust"
lifestyle. When conditions in the upper mixed layer (nutrients and light) are favourable (e.g. at the
start of spring) their competitive edge (Furnas, 1990) allows them to quickly dominate
phytoplankton communities ("bloom"). As such they are often classed as opportunistic r-strategists
(i.e. those organisms whose ecology is defined by a high growth rate, r).

When conditions turn unfavourable, usually upon depletion of nutrients, diatom cells typically
increase in sinking rate and exit the upper mixed layer ("bust"). This sinking is induced by either a
loss of buoyancy control, the synthesis of mucilage that sticks diatoms cells together, or the
production of heavy resting spores.

Sinking out of the upper mixed layer removes diatoms from conditions inimical to growth, including
grazer populations and higher temperatures (which would otherwise increase cell metabolism).

Cells reaching deeper water or the shallow seafloor can then rest until conditions become more
favourable again. In the open ocean, many sinking cells are lost to the deep, but refuge
populations can persist near the thermocline.

Ultimately, diatom cells in these resting populations re-enter the upper mixed layer when vertical
mixing entrains them. In most circumstances, this mixing also replenishes nutrients in the upper
mixed layer, setting the scene for the next round of diatom blooms. In the open ocean (away from
areas of continuous upwelling; see Dugdale & Wilkerson, 1998), this cycle of bloom, bust, then
return to pre-bloom conditions typically occurs over an annual cycle, with diatoms only being
prevalent during the spring and early summer.
Golden algae

Coccolithophores are single-celled algae,
or phytoplankton, belonging to the
haptophytes.

They are distinguished by special calcium
carbonate plates (or scales) of unknown
purpose called coccoliths, which are
important microfossils.

Coccolithophores are exclusively marine
and are found in large numbers throughout
the surface euphotic zone of the ocean.

Due to their microscopic size and broad
distribution, coccoliths (calcareous
nannoplankton) have become very popular
for solving various stratigraphic problems,

and many studies have been devoted to that
end. Nanofossils are sensitive indicators of
changes in the temperature and salinity of
the ocean and sea surface water.

Quantitative analysis of calcareous
nanoplankton assemblages is being
employed to reveal such changes.
Brown Algae

The brown algae are a large
group of multicellular, mostly
marine, algae.

They play an important role in
marine environments. For
instance Macrocystis, may reach
60 metres in length, and forms
prominent underwater forests.

Another notable example is
Sargassum, which creates unique
habitats in the Sargasso Sea
(hence the name Sargassum).

Many brown algae such as
members of the order Fucales (the
rockweeds) are commonly found
along rocky seashores. Some
members of the division are used
as food.
Green Algae
A growth of the green seaweed, Enteromorpha on rock
substratum at
the ocean shore. Some green seaweeds, such as
Enteromorpha and Ulva,
are quick to utilize inorganic nutrients from land runoff,
and thus can be indicators of nutrient pollution.

The Green algae (singular: Green
Alga) are the large group of algae
from which the embryophytes (higher
plants) emerged.

As such they form a paraphyletic
group, variously included among the
Plantae or with the Protista.

The green algae include unicellular
and colonial flagellates, usually but
not always with two flagella per cell,
as well as various colonial, coccoid,
and filamentous forms.
Red Algae

The red algae (Rhodophyta, IPA:
[ˌrəʊdə(ʊ)ˈfʌɪtə], from Greek:
ῥόδον (rhodon) = rose + φυτόν
(phyton) = plant, thus red plant)
are a large group of mostly
multicellular, marine algae,
including many notable seaweeds.
Most of the coralline algae, which
secrete calcium carbonate and
play a major role in building coral
reefs, belong here. Red algae
such as dulse and nori are a
traditional part of European and
Asian cuisine and are used to
make other products like agar,
carrageenans and other food
additives.
Red Algae


The oldest fossil identified as a red alga is also the
oldest fossil eukaryote that belongs to a specific
modern taxon. Bangiomorpha pubescens, a
multicellular fossil from arctic Canada, strongly
resembles the modern red alga Bangia despite
occuring in rocks dating to 1200 million years ago.[1]
Red algae are important builders of limestone reefs.
The earliest such coralline algae, the solenopores, are
known from the Cambrian Period. Other algae of
different origins filled a similar role in the late
Paleozoic, and in more recent reefs.
Red Algae

Several species are used as food. Dulse
(Palmaria palmata) and Porphyra are
perhaps the best known[4

They have cell walls that are made out of
cellulose and thick gelatinous
polysaccharides which are the basis for most
of the industrial products made from red
algae.
Summary
Protozoa
Protists
Protozoa
Algae
Amoebas
Forams
Actinopods
Zooflagellates
Amoebic
Dysentery
Index fossils
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Ciliates
Apicomplexans
Fungus-Like Protists
Plasmodium;
Malaria
Algae
Euglenoids
Create
green and opaque
water problems
in aquariums.
Diflagellates
Major producer in
marine ecosystems
Zooxanthellae;
toxic blooms
(Red tides)
Diatoms
Golden Algae
Brown Algae
Major component of
Ocean’s minute
plankton
Ecological importance
in cooler ocean water
Green Algae
Red Algae
Ecological importance
in tropical ocean
Reef building
Fungus-like protista
Fungus-like protista
Plasmodial Slime
molds
Multinucleate plasmodium
Physantum: Model to
study many biological
processes
Cellular slime molds
Water molds
Individual ameboid cells
Coenocytic mycelium
Dictostelium: model to
study many biological
processes
Phytophthora: serous
plant disease
Ex: late blight of potato
Haploid spores
Asexual spores
Asexual (zoospores)
Sexual (oospore)
Water moulds

Water moulds or Oomycetes are a group
of filamentous, unicellular protists, physically
resembling fungi.

They are microscopic, absorptive organisms
that reproduce both sexually and asexually
and are composed of mycelia, or a tube-like
vegetative body

The name "water mould" refers to the fact
that they thrive under conditions of high
humidity and running surface water.

Their cell walls are composed of cellulose
rather than chitin and generally do not have
septations.

Also, in the vegetative state they have
diploid nuclei, whereas fungi have haploid
nuclei.

Phytophthora cinnamomi (dieback) - this
affects as many as 2000[1] of the 9000
native plant species in Southwest
Australia, most notably jarrah (Eucalyptus
marginata).

The water moulds are
economically and
scientifically important
because they are
aggressive plant
pathogens (see plant
pathology). The majority
can be broken down into
three groups, although
more exist.

Potato blight
The Phytophthora
group is a genus that
causes diseases such
as dieback, potato
blight, sudden oak
death
Infected oak; It was first discovered in California in 1995 when large
numbers of Tanoaks (Lithocarpus densiflorus) died mysteriously, and was described as a
new species of Phytophthora in 2000
Summary
Protozoa
Protists
Protozoa
Algae
Amoebas
Forams
Actinopods
Zooflagellates
Amoebic
Dysentery
Index fossils
Diagnostic fossils
Trypanosoma;
african sleep
sickness
Giardia;
Fungus-Like Protists
Plasmodial Slime
molds
Multinucleate plasmodium
Diflagellates
Diatoms
Golden Algae
Brown Algae
Green Algae
Major producer in
marine ecosystems
Zooxanthellae;
toxic blooms
(Red tides)
Major component of
Ocean’s minute
plankton
Plasmodium;
Malaria
Ecological importance
in cooler ocean water
Cellular slime molds
Water molds
Individual ameboid cells
Coenocytic mycelium
Dictostelium: model to
study many biological
processes
Phytophthora: serous
plant disease
Ex: late blight of potato
Red Algae
Physantum: Model to
study many biological
processes
Create
green and opaque
water problems
in aquariums.
Apicomplexans
Fungus-like protista
Algae
Euglenoids
Ciliates
Ecological importance
in tropical ocean
Reef building
Haploid spores
Asexual spores
Asexual (zoospores)
Sexual (oospore)
Green algae
Charophytes
Plants
Plants and green algae has similar
biochemical characteristics
Same biosynthetic pigment
 Same cell wall component
 Same carbohydrates storage material

Plants and green algae share
similarities in cell division.
What is different in plants?
Green algae
Charophytes
Evolution of number of anatomical, physiological and reproductive adaptations
Plants
Land colonization
Plant features

Plant cuticles are a
protective waxy covering
produced only by the
epidermal cells
(Kolattukudy, 1996) of
leaves, young shoots and
all other aerial plant
organs.

The cuticle is composed
of an insoluble cuticular
membrane impregnated
by and covered with
soluble waxes.
Plant, stomata

In botany, a stoma (also stomate; plural
stomata) is a tiny opening or pore, found
mostly on the under-surface(epidermis) of a
plant leaf, and used for gas exchange.

The pore is formed by a pair of specialised
cells known as guard cells which are
responsible for regulating the size of the
opening.

Air containing carbon dioxide and oxygen
enters the plant through these openings
where it gets used in photosynthesis and
respiration. Waste oxygen produced by
photosynthesis in the chlorenchyma cells
(parenchyma cells with chloroplasts) of the
leaf interior exits through these same
openings.

Also, water vapor is released into the
atmosphere through these pores in a
process called transpiration.
Gametangia

is an organ or cell in
which gametes are
produced.

Most plants produce
multicellular
gametangia with a
protective jacket of
sterile cells
surrounding the
gametes.
Plant, Reproduction

Antheridia are gametandia that produce
SPERM cells

Archegonia are gametangia that produce
EGGS.
Plant, Reproduction

Mosses have motile
sperm that swim in
water and fertilize the
egg
Plant, transport system

The vascular plants are
plants in the kingdom
Plantae (also called
Viridiplantae) that have
specialized tissues for
conducting water.
Vascular plants include
the ferns, clubmosses,
horsetails, flowering
plants, conifers and other
gymnosperms.
Plant, transport system


xylem is one of the two types
of transport tissue in plants,
phloem being the other one.
The word “xylem” is derived
from classical Greek ξυλον
(xylon), "wood", and indeed the
best known xylem tissue is
wood, though it is found
throughout the plant.
The xylem transports sap from
the root up the plant. Xylem
sap consists mainly of water
and inorganic ions, although it
can contain a number of
organic chemicals as well.
Plants, alteration of generations
plant life cycle has an
alteration of
generations in which
they spend part of
their life cycles as a
muticellular haploid
gaetophyte and part
as a muticellular
diploid sporophyte
Seeds

A seed contains the embryo from which a new
plant will grow under proper conditions.

Seeds also usually contain a supply of stored
food and is wrapped in the seed coat or testa.

In angiosperms, the stored food begins as a
tissue called the endosperm, which is derived
from the parent plant via double fertilization.

The usually triploid endosperm is rich in oil or
starch and protein.

In gymnosperms, such as conifers, the food
storage tissue is part of the female
gametophyte, a haploid tissue.
Seeds


Endosperm is tissue produced in the seeds of most
flowering plants around the time of fertilization. It
surrounds the embryo and provides nutrition in the in the
form of starch, though it can also contain oils and
protein.
Endosperm is formed when the two sperm inside a
pollen grain reach the interior of an embryo sac or
female gametophyte. One sperm fertilizes the egg,
forming a zygote, while the other sperm usually fuses
with the two female nuclei at the center of the ovary,
creating endosperm (double fertilization). Thus
endosperm cells are usually triploid (containing three
sets of chromosomes) but can vary widely from diploid
(2n) to 15n.
Vascular Plants
With seeds
Gymnosperms
Seeds are totally exposed or windborne
on the scales of cones
Angiosperms
(flowering plants)
Produce seeds enclosed within a fruit
Gymnosperms
Pinophyta –
Conifers
Ginkgophyta –
Ginkgo
Cycadophyta Cycads
Gnetophyta –
Gnetum,
Ephedra,
Welwitschia
Gymnosperms

Gymnosperms
(Gymnospermae) are a group
of seed-bearing plants with
ovules borne on the edge or
blade of an open sporophyll,
the sporophylls usually
arranged in cone-like
structures. The term
gymnosperm comes from the
Greek word gumnospermos,
meaning "naked seeds" and
referring to the unenclosed
condition of the seeds, as
when they are produced they
are found naked on the scales
of a cone or similar structure.
Pinophyta –
Conifers





Largest phylum of
gymnosperms
Woody plants
Bear evergreen
needles.
Produce seeds on
cones.
Have separate male
and female on
separate cones on
the same plant.
Pinophyta – Conifers
SAME PLANT; MONOECIOUS
Male
cone
Pollen grains
Femal
e
Cone
By Air
Fertilization
zygote
Embryo within the seed
Wind dispersal
Cycadophyta - Cycads
Male
cone
Pollen grains
Femal
e
Cone
By Air
Plant A
Plant B
TWO PLANTS;DIOECIOUS
Cycadophyta - Cycads
Female
Cone

Cycads are an ancient group
of seed plants characterized by
a large crown of compound
leaves and a stout trunk. They
are evergreen,
gymnospermous, dioecious
plants having large pinnately
compound leaves.

Some are renowned for
survival in harsh semi-desert
climates, and can grow in sand
or even on rock. They are able
to grow in full sun or shade,
and some are salt tolerant.
Male Cone
Cycadophyta - Cycads
Gnetophyta

The gnetophytes differ from other gymnosperms in
having wood vessels as in the flowering plants
(Angiosperms or Magnoliophytes), and on the basis of
morphological data it has been suggested that
Gnetophytes may be the group of spermatophytes most
closely related to the flowering plants.

Molecular data have suggested a closer relationship to
other gymnosperms than to angiosperms, and the
conflict between morphological and molecular data has
not yet been resolved.
Gnetophyta
Flowering plants angiosperms
Vascular plants
 Seeds enclosed within fruits
 Most diverse and most scceussful group of
plants
 Why?

Flowering plants, special features

Flowers: function in sexual production

Double Fertilization: diploid zygote and
triploid zygote: Endosperm.
Ovule enclosed within the ovary.
 Ovule: seed
 Ovary: Fruit




Efficient water –conducting cells called vessel elements
in their xylem
A vessel element is one of the cell types found in xylem,
the water conducting tissue of plants. Vessel elements
are typically found in the angiosperms but absent from
most gymnosperms such as the conifers.
Vessel elements are the building blocks of vessels,
which constitute the major part of the water transporting
system in the plants where they occur. Vessels form an
efficient system for transporting water (including
necessary minerals) from the root to the leaves and
other parts of the plant.

Efficient carbohydrate conducting cells
(sieve tube) members in their system.
Various ways of fertilization
Wind
 Water
 Insects
 Other animals
 All can transfer pollen grains.

Flower plants; types
Monocots
Floral parts: multiples of three
Seeds: one cotyledon
Seeds: Nutritive tissue: Endosperm
Diocots
Floral parts: multiples of four or five
Seeds: two cotyledon
Seeds: Nutritive tissue: cotyledons
Cotyledon

A cotyledon (Greek: κοτυληδών) is a
significant part of the embryo within the
seed of a plant.

Upon germination, the cotyledon usually
becomes the embryonic first leaves of a
seedling.

The number of cotyledons present is one
characteristic used by botanists to classify
the flowering plants (angiosperms).

Species with one cotyledon are called
monocotyledonous (or, "monocots") and
placed in the Class Liliopsida.

Plants with two embryonic leaves are
termed dicotyledonous ("dicots") and
placed in the Class Magnoliopsida.
Seed Plants, origin




Theory:
Seed plants probably arose from seedless
vascular plants; Progymnosperms.
Progymnosperms (have large leaves
(megaphylls) and woody tissue.
Amborella (dicot) nearest living to the ancestor
of all flowering plants
Mosses

Mosses are small, soft plants that are
typically 1-10 cm tall, occasionally
more.

They commonly grow close together in
clumps or mats in damp or shady
locations.

They do not have flowers or seeds,
and their simple leaves cover the thin
wiry stems.

At certain times mosses produces
spore capsules which may appear as
beak-like capsules borne aloft on thin
stalks.
Cuticle, stomata multicellular gametangia
No seeds no vessels
Bryophytes

The bryophytes are those embryophyte
plants ('land plants') that are non-vascular:
they have tissues and enclosed
reproductive systems, but they lack
vascular tissue that circulates liquids. They
neither flower nor produce seeds,
reproducing via spores.