Introduction to Plants
lants are multicellular
eukaryotes whose cells have cell
walls. Most plants are
autotrophs-they produce their
own food through
hotosynthesis is the process by
which plants produce organic
materials from inorganic
materials by using energy from
the sun and carbon dioxide.
hotosynthesis occurs in
Establishments of plants on Land
n order to thrive on land plants
• Absorbed nutrients from the soil
through their roots.
• Prevent water loss using cuticles,
which are a waxy fatty and
watertight layer on the external
wall of epidermal cells.
• Dispersal on land when the
releases the spores, which are a
reproductive cell or multicellular
structure that is resistant to the
Plant Life Cycles
• Sporophyte in plants and algae
that have alternation of
generations, the diploid
individual or generation that
produces haploid spores.
• Gametophyte in alternation of
generations, the phase in
which gametes are formed; a
haploid individual that
• Plants have life cycles in which
alternate with diploids
• A life cycle in which a
gametophyte alternates with
sporophyte called alternation
Characteristics of a Nonvascular Plants
onvascular plants are small plants that reproduce by means of
spores. They lack true roots, stems, and leaves, which are complex
structures that contains vascular, or conducting tissues.
ater is transport by diffusion and osmosis.
xample of Nonvascular Plants:
eproduction in Nonvascular Plants
• In the life cycle of nonvascular plants, the gametophyte is the dominant
generation. Gametophytes must be covered by a film of water in order for
fertilization to occur.
Characteristic of a Seedless Vascular Plants
porophytes of seedless vascular plants have vascular tissue, but
gametophytes lack vascular tissue. Because of their vascular system,
vascular plants grow much larger than nonvascular plants and also develop
true roots, stems, and leaves.
here are two major groups of seedless vascular plants:
• Lycophytes, like the club moss, have roots, stems, and leaves. Their leafy
green stems branch from an under ground rhizome. Rhizomes are
horizontal, underground stems. Spores develop in the sporangia that
form a specialized leaves name cones.
• Monilophytes, like the ferns, have rhizomes that are anchored by roots
and have leaves called fronds.
eedless vascular plants can reproduce sexually only when a film of water
covers the gametophyte. Unlike nonvascular plants, seedless vascular have
sporophytes that are much larger than their gametophytes.
pores is a haploid reproductive cell. A spore is produce by meiosis and is
capable of developing into an adult without fusing with another cell. The
Characteristics of a Seed Plant
• Kind of seed plants:
• Gymnosperms are vascular seed plants whose seed are not enclosed by a fruit.
• Angiosperms a flowering plant that produce seed within a fruit.
• Seed plants don’t required water to reproduce sexually. Reproduction in seed
plants is also characterized by greatly reduced gametophyte and a dominant
• Sporophyte produce two kind of spores that develop in two kind of gametophyte:
• Female gametophyte, which produce eggs called ovule that develops into a
• Male gametophyte, which produce sperm that is called the pollen gratin.
• The process steps of reproduction of seed plants are:
• Pollination and Fertilization
• Seed formation
• Seed dispersal:
• Dispersal by wind
• Dispersal by Animal
here are for major groups of
eproduction in conifers is
characterized by a dominant
sporophyte, wind pollination,
and the development of seed in
ones are the gametophytes of
Characteristics of Flowering Plants
ind of Angiosperms:
• Have one cotyledon, the embryonic leaf in the seed.
• Leaves have parallel venation
• Flower parts usually occurs in multiple of three
• Two cotyledons
• Leaves have net venation
• Flowers parts usually occurs in multiples of four or five.
flower is a specialize reproductive structure of angiosperms. The male and female
gametophytes develop within the flower, which promote pollination and
he flowers of many angiosperms are adapted for pollination by wind
or by animals.
• Flowers contains structural elements to attract animals (color, odor, food source)
• Some flowers are pollinated by insect moving from flower to flower.
• Flowers are small
• Flowers lack elements to attract pollinators
he ovary of the pistil is called a
fruit after its ovules are
fruit is the structure that is
develop from a ovary of a
flower and contains seeds.
lthough fruits provide some
protection from developing
seeds, they primarily function
in seed dispersal.
lants reproduce asexually in a variety of ways that involves
nonreproductive parts, such as stems, roots, and leaves. The
reproduction of plants from these parts is called vegetative
any of the structures by which plants reproduce vegetatively are
modified stems, such as bulbs, tubers, runner, and stolons.
Plant Tissue Systems
ascular plants have three
• The dermal tissue forms the
protective outer layer of the
• The vascular tissue forms
strands that conduct water,
minerals, and organic
compounds throughout a
• Ground Tissue makes up
much of the inside of the
non-wood parts of a plant,
including roots, stems, and
Dermal Tissue Systems
ermal tissue covers the outside of a plant’s body. In the non-wood parts,
dermal tissue forms a “skin” called epidermis.
he epidermis is made of single layer of flat cells.
xtension of epidermis in stems and leaves helps to slow water loss.
xtension of epidermis in root tips are called root hairs, help increase the
absorption of water.
n woody stems the epidermis and roots consist in dead cells called cork,
that helps in gas exchange and absorption of minerals nutrients.
tomata are opening in a leaf or
steam of a plant that enables gas
exchange to occur.
t exchange carbon dioxide and
tomata have a guard cell that is a
pair of specialized cells that
borders a stoma and regulate gas
Vascular Tissue System
ascular plants have two kinds of
vascular tissues, called the
xylem and phloem, that
transport water, minerals, and
nutrients throughout the plant.
ylem is the type of tissue in
vascular plants that provides
support and conducts water
and nutrients from the roots.
hloem is the tissue that carries
organic and inorganic nutrients
in any direction, depending on
the plant’s needs.
Ground Tissue Systems
round Tissue makes up
much of the inside of
most non-woody plants,
where it surrounds and
supports vascular tissue.
ost plants are anchored to
the spot where they grow by
roots, which absorb water
and mineral nutrients.
n many plants, roots also
function in the storage of
organic nutrients, such as
sugar and starch.
here are two types of roots:
• Fibrous roots
tems support the leaves and house the vascular tissue, which transport
substances between the roots and the leaves.
tems can be:
eaves are the primary
photosynthetic organ of
any plants have modified
leaves that are specialized
for particular functions.
he plants possesses an
embryonic root and embryonic
shoot. Leaflike structures called
cotyledons, or seed leaves, are
attached to the embryonic
ermination is the beginning of
growth or development in a
seed, spore, or zygote,
especially after a period of
lants grow by producing new cells in
regions of active cell division called
eristems are a region of
undifferentiated plant cells that are
capable of dividing developing into
specialized plant tissues.
rimary growth is the growth that
occurs as a result of cells division at the
tip of stems and roots and that gives
rise to primary tissue.
• Apical Meristems
econdary growth is the growth that
results from cell division in the cambia,
Calvin Cycle in Plants
he Calvin Cycle is a metabolic
pathway found in the stroma of
the chloroplast in which carbon
enters in the form of CO2 and
leaves in the form of sugar.
he reactions in Calvin Cycle are
also called light-independent
reactions of photosynthesis are
chemical reactions that convert
carbon dioxide and other
compounds into glucose.
he cycle spends ATP as an energy source and consumes NADPH2 as
reducing power for adding high energy electrons to make the sugar.
There are three phases of the cycle.
• In phase 1 (Carbon Fixation), CO2 is incorporated into a five-carbon sugar
named ribulose bisphosphate (RuBP). The enzyme which catalyzes this
first step is RuBP carboxylase or rubisco. It is the most abundant protein in
chloroplasts and probably the most abundant protein on Earth. The
product of the reaction is a six-carbon intermediate which immediately
splits in half to form two molecules of 3-phosphoglycerate.
• In phase 2 ( Reduction), ATP and NADPH2 from the light reactions are used
to convert 3-phosphoglycerate to glyceraldehyde 3-phosphate, the threecarbon carbohydrate precursor to glucose and other sugars.
• In phase 3 (Regeneration), more ATP is used to convert some of the of the
pool of glyceraldehyde 3-phosphate back to RuBP, the acceptor for CO 2,
thereby completing the cycle. For every three molecules of CO 2 that enter
the cycle, the net output is one molecule of glyceraldehyde 3-phosphate
(G3P). For each G3P synthesized, the cycle spends nine molecules of ATP