Module2 Botany 100

Cell Cycle

Events cell goes through to grow

Meristems

Regions of active cell division

Binary Fission

How Prokaryotes replicate

DNA when Coiled

Chromosomes

G1 Phase

Cell grows, makes membrames + organelles

S Phase

DNA Synthesis, chromosome replication

G2 Phase

Gap to prep for Mitosis

Interphase

Cell grows in size and prepares to divide (90% of cycle)

Mitosis

Cell divides (10% of cycle)

Helicase

Enzyme that “unzips” the two DNA strands

DNA polymerase

Enzyme the constructs the new strand

Prophase

Chromosomes Condense → chromotids, Nuclear Envelope disintegrates

Metaphase

Chromosomes align in center of cell

Anaphase

Sister Chromatids separate to opposite ends

Telophase

New Nuclei Form

Cytokinesis

One cell becomes two identical daughter cells. Cytoplasm is divided

Mitosis/Cytokinesis Checkpoint

Spindle Assembly Checkpoint

G1/S Phase Checkpoint

if cell too small, not enough energy, on different path, it will not enter S phase

G2/M Checkpoint

if DNA replication has errors, will not enter M phase

3 main types of plant cell types

Parenchyma, Collenchyma, Sclerenchyma

Parenchyma Cells

Thin-walled, actively dividing, diverse functions. All plant cells start as parenchyma. Your basic plant cell.

Collenchyma Cells

Living cells, thick walls and very strong

Sclerenchyma Cells

Permanant Cells, long lasting, long term support for the body.

Level of plant cell organization

Leaf → Organ → Tissue → Specialized Cells

G0 Phase

Resting Phase, Stasis

Tissues

Made up of one or more different cell types

Differentiation

How specialized cells are made

Primary Meristems

Produce primary tissues that develop into organs, stems, and roots. Produce axillary buds that develop into new branches

Primary Growth

Increase in length/height

Secondary growth

Increase in thickness/diameter

Secondary meristems

Secondary Growth, produce wood in woody plants

Apical Dominance

Terminal Bud dominates growth, suppresses axillary buds

3 Primary tissue types

Dermal, Vascular, Ground

Dermal Tissue

Complex tissue making up protective outer layer

Componants of Dermal Tissue

Epidermis, Cuticle, Guard Cells, Trichomes

Vascular Tissue

Complex tissue creating internal transport system

Function of Vascular Tissue

Moves water, nutrients, and sugars throughout plant

Xylem

Vascular Tissue responsible for moving water and minerals

Phloem

Vascular tissue responsible for moving sugars

Ground Tissue

Simple tissues that comprise bulk of plant body

Function of Ground Tissue

Fills space in plant body, provides structure, and metabolism

Herbaceous Plants

Do not have wood, short in stature, short lifespans, lack secondary growth

Woody Plants

Have stems reinforced with Lignin

What is a Tree

Woody plant with a dominant stem

What are Shrubs

Woody Plants with multiple stems

Abiotic Factors

Non-living factors

Biotic Factors

Living factors

Phototropism

Plants grow towards light sources

Auxin Hormone

Regulates location of cell growth, mediates phototropism, delays ripening

Cytotoxins Hormones

Regulates cell division

Gibberellins (GA)

Promotes cell elongation (plant height), flowering

Abscisic Acid (ABA) Hormone

Inhibits Growth, sugar transport, water stress responses

Ethylene Hormone

Promotes ripening, also a Gas

Phenology

Timing of growth, reproduction, senescence in plants

Senescence

Aging and tissue death

Deciduous Plants

Plants that lose their leaves and go dormant due to seasonal changes

Evergreen Plants

Plants that adapt to keep leaves year-round regardless of seasonal changes