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• Growth is the increase in mass from cell division and expansion.
• Development is the sum of all changes that progressively elaborate an organism's body.
• Intermediate growth means continuous growth for the organism's lifespan.
• Determinate growth means growth ceases at a certain point or age.
• Plants that complete their life cycle in one year or less are annuals.
• Biennials are plants that live for two years, often with a cold period between vegetative and flowering seasons.
• Perennials are plants that live for many years, like trees, shrubs, and some grasses.
• Meristems are regions where cell division occurs, enabling plants to grow wider or taller.
• Apical meristems are located at root tips and shoot buds, supplying cells for growth in length.
• Primary growth allows roots to explore the soil and shoots to reach for light, restricted to the youngest parts in woody plants.
• Secondary growth involves the progressive thickening of roots and shoots.
• Lateral meristems contribute to secondary growth, forming cylinders of dividing cells along the length of roots and shoots in older regions.
• Primary growth produces the primary plant body, which includes the parts of the root and shoot system from apical meristems.
• The root is protected by a root cap, which also secretes lubricating slime, and growth is concentrated near the root tip.

Root Zones

• Zone 1: Cell Division including the apical meristem and its derivatives, primary meristems, with a quiescent center of slower-dividing, resistant cells.
• Zone 2: Elongation where cells elongate significantly, pushing the root tip forward, sustained by meristem adding cells.
• Zone 3: Maturation where cells specialize in structure and function, with tissues from primary growth completing their differentiation.

Primary Root Tissues

• Dermal tissue: Epidermis (rhizodermis)
• Ground tissue: Cortex with endodermis
• Vascular tissue: Xylem and phloem

Root Vascular Structure

• Dicots xylem cells radiate from the stele's center with phloem between spokes.
• Monocots stele has vascular tissue ringed patterns of xylem and phloem
• The shoot apical meristem, at the terminal bud, is a dome-shaped mass of dividing cells. It forms protoderm, procambium, and ground meristem.
• Leaves arise as leaf primordia on the flanks of the apical meristem. Axillary buds develop from meristematic cells left by apical meristems at the leaf primordia base.
• Leaf primordia develop from meristem; shoot elongation occurs in slightly older internodes below the shoot apex, due to cell division and elongation.
• Axillary buds can form branches of the shoot system.
• Branches originate from axillary buds, unlike lateral roots.
• Vascular bundles run the length of the stem, converging as the root's vascular cylinder at the root and shoot connection location.
• Ground tissue surrounds each vascular bundle of the stem.
• Dicot stem vascular bundles are arranged in a ring, with pith inside and cortex outside. Xylem faces the pith, and phloem faces the cortex.
• Monocot vascular bundles are scattered throughout the ground tissue.
• The epidermis is composed of tightly locked cells on both sides of the leaf, serving as a defense against damage and pathogens, plus a waxy cuticle to prevent water loss.
• Stomata are pores in the epidermis, flanked by guard cells, that allow gas exchange and are the major site of water loss through transpiration.
• Mesophyll is located between the upper and lower epidermis. It is equipped with chloroplasts which are specialized or photosynthesis. Carbon dioxide and oxygen circulate in air spaces, particularly near stomata.
• Xylem transports water and minerals to photosynthetic tissues.
• Phloem carries sugars and organic products to other parts of the plant, affecting leaf shape.

Secondary Growth

• Secondary growth increases the girth of stems and roots in dicots due to tissues produced from this type of growth in diameter.
• The vascular cambium produces secondary xylem and phloem.
• The vascular cambium accounts for most of the diameter increase in woody plants, forming secondary xylem to the interior and secondary phloem to the exterior.
• The cork cambium produces a tough covering of stems and roots, replacing the epidermis. Cork is produced.
• Secondary growth continues over the years, accumulating layers of secondary xylem to produce wood.

Wood Formation

• Early wood (spring): Has larger diameter and thinner walls that maximizes water delivery to new leaves.
• Late wood (summer): Provides physical support through thick-walled cells.
• Cambium dormancy, early and late wood production create annual growth rings.
• Cork cambium produces cork cells that accumulate on its exterior, forming a barrier against water loss, damage, and pathogens.
• Periderm, composed of cork, phelloderm, and cork cambium, replaces the epidermis.
• Lenticels are splits in the periderm that facilitate gas exchange through heightened cork cambium activity.

Bark

• Bark includes all tissues external to the vascular cambium, including secondary phloem, phelloderm, cork cambium, and cork with only the youngest secondary phloem functions in sugar transport.
• Older secondary phloem protects the stem and is shed as bark.
• After years of secondary growth, zones in stems include secondary xylem, the vascular cambium, living secondary phloem, cork cambium, and cork.
• Older root parts anchor the plant and transport water/solutes and with years, annual rings and tissues external to the vascular cambium form a thick bark.

Life Cycle

• Stages: Germination, growing plant, flowering, pollination, fertilization, and seed dispersal.
• Sexual reproduction leads to the production of an embryo involving the fusion of sex gametes.
• Asexual reproduction involves vegetative growth.
• Portion from mature sporophyte creates a genetically identical progeny
• Male angiosperm gametophyte is comprised of the filament and anther.
• The female gametophyte is comprised of the stigma, style and ovary

Pollination

• In angiosperms, there is a transfer of pollen from the anther to the stigma.
• Pollinators transfer pollen from anther to carpel stigma.
• Pollination syndromes are flower traits that attract pollinators.

Ways to Pollinate the Stigma

• Wind
• water
• insects
• animals
• Biotic pollination (by animals) accounts for 80% of all pollination.
• Entomophily is pollination by insects like bees, wasps, ants, beetles, moths, and butterflies.
• Zoophily is pollination by animals, such as birds and bats.
• Abiotic pollination uses non-animal factors.
• Anemophily is wind pollination and accounts for 98% of abiotic pollination.
• Hydrophily: Pollination by water through aquatic plants
• Successful pollination leads to formation of the pollen tube and the fertilization of the egg.

Pollinators vs Pollenizers

• Pollinator: Agent that moves pollen
• Pollenizer: The plant that provides pollen
• Self-fertile plants can pollinate themselves, while others need cross-pollination due to chemical or physical barriers.
• Recognition factors prevent self-fertilization, ensuring genetic variability, through an "immune system"-like recognition of "self" proteins in pollen.
• Self-incompatibility: A plant rejects its own pollen and related individuals' pollen; some plants prevent self-fertilization with stamens and pistils developing at different times or arranged to limit self-transfer.

Flower Type

• Pin flowers have long styles and short stamens.
• Thrum flowers have short styles and long stamens.
• Cross-pollination (syngamy) transfers to an external pollenizer, delivering pollen to a flower on a different plant.
• Self-pollination, or autogamy, moves pollen within the same flower.
• The pistil adapts to self-pollination when the stamens and carpels are the same length,.
• Cleistogamy is autogamy inside a closed flower. The cleistogamous flower is this closed.
• Many crop plants are self-pollinating to prevent self-fertilization e.g., laborious anther removal or sterile males. Peach varieties are often autogamous, aided by insects transferring pollen on the same plant.
• Hybridization is effective pollination across species within a genus or across different genera.
• Each ovule has megasporangium tissue that contains a diploid megaspore mother cell that undergoes meiosis to produce 4 haploid megaspores.
• Nucleus of the last megaspore divides three times without cytokinesis, creating one large cell with eight haploid nuclei. Membranes then divide these up to make the fully developed female gametophyte.

Embryo Sac Components

• Three antipodal nuclei (antipodal cells) at one end of the sac are of unknown function.
• Two polar nuclei not partitioned but share the cytoplasm.
• Two synergids flank the egg opposite of the sac functions.
• One egg is also present.
• After landing on the stigma, pollen grains absorb moisture and germinate.
• Pollen tube extends toward the ovary and ovules, where the generative nucleus undergoes mitosis to form two sperms.
• The tube nucleus precedes and extends the pollen tube, which enters the ovule (micropyle) and releases sperms

Double Fertilization

• One sperm fertilizes an egg that creates zygote to form the embryo.
• The second fertilization involves the union of the second sperm with two polar nuclei, to form a triploid nucleus in the center of the ovule.
• A triploid cell gives rise to endosperm food storage tissue of the seed.
• After fertilization, the ovule develops into seed (embryo, endosperm and integuments).

Seed Formation

• The first division of the zygote is asymmetric.
• Seed coat from ovule integuments and tissue of the ovary becomes the fruit.
• Fruits aid in seed dispersal via wind, animals, or explosive mechanisms.
• Asexual reproduction (natural vegetative propagation) happen without human involvement with new plants from underground stems, roots, and leaves.
• A bulb is that stores food and includes onion, lily, hyacinth and tulip.
• A corm is thick, contains stored food and stordes food, e.g., Gladiola and begonia.
• A tuber is an enlarged stem that acts as the storage unit for food; buds and roots develop here, e.g., potato.
• Rhizomes are horizontal underground stems near the surface that are also storage units of food. Example: ginger
• Stolons stems grow across the ground and grow new leaves and roots when nodes touch the Example: strawberry and bermuda.
• Some storage roots grow new roots. Example: turnip, carrot, radish, and sweet potato
• Leaves can separate from plants and continue growingExample: Katakataka and Begonia
• Artificial vegetative propagation which is by people and is useful for production for decoration and food

Artificial Propagation

• Cutting: Where cuttings grow into new, independent plants.
• Layering: Where stems are encouraged to grow roots before being separated and planted as separate individuals
• Grafting: Where food and water are shared and branched or stems are cut and connected
• Budding: From a cut must fit the mother plant
• Marcotting requires healthy maturity in order to remove stems
• Cloning uses tissue culture
• Roots functions include anchorage, support, absorption, conduction, storage, photosynthesis, aeration, movement and reproduction
• Root of cell division comprises the apical meristem and root cap.
• The area of elongation lies 5-10 mm in length.
• The area of differentiation/maturation can reach a few cm, with 400 root hairs per mm^2.
• Growth of a single root hairs occurs at a part of a single.
• Root hairs absorb water and minerals from the soil with insoluble minerals digestible acids that they excrete.

Meristems

• Primary meristems are located at the tips of the roots
• Secondary meristems develop from procambium and e.g., dicots, and are lateral that extend roots and shoots.
• Xylem (water conducting tissue) consists of vessel and treacheids
• Pholem (conducting organic materials) consists of companion tube, schlerenchyma and parenchyma
• Dicot primary roots have vascular tissues and the central parts differ
• Periderm is made of cork cambium and replaces the epidermis
• Some are anatomy of modified structures
• Apical meristem and axillary buds for primodium, the developing of leaves
• Stem arise with the meristem and have primary structure
• Some leaves have midrib, margin and tip while leaf base has a stem and axil. Vessels can be identified a the leaf blase.
• Stomata are located bw two epidermis, guard cell
• Gametes occur in anthers and ovaries