Plants on Stefano Chiodino

Why are plants green?

Fri, 07 Aug 2020 00:00:00 +0000

Most of the sun’s energy is in the green wavelength, however that’s exactly what the plants bounce back, as chlorophyll of type a and b absorbs light in the red and blue spectrum.

It was thought that collecting too much of the available wavelength could harm the plant (think of how hot black surfaces can become). However it has recently been discovered that plants are trying to optimise for a steady flux of energy, because flickers in the energy collected can cause energy failures or tissue damage.

In the long run evolution selects for performances, but also stability.

Source: Reddit /r/til

Ref: https://www.quantamagazine.org/why-are-plants-green-to-reduce-the-noise-in-photosynthesis-20200730/

Monocote vs dicot plants

Sun, 07 Jun 2020 00:00:00 +0000

Dicots and monocots differs on several more features other than the one that gives them their names: the number of cotyledon (leafs) in their embryo. Monocots have parallel veins in their leafs, which usually means elongate leafs as well, complexly arranged vascular system, fibrous roots, and floral parts usually in multiple of three. Dicots have a network of branching veins, a vascular system arranged in rings, a taproot system (a long main root), and floral parts usually arranged in multiple of four or five.

Source: Coursera’s Understanding Plants - Part II: Fundamentals of Plant Biology Week 2 2.1 Plant organs.

URL: https://www.coursera.org/learn/plant-biology/lecture/4927r/2-1-plant-organs

Plasmodesma

Fri, 05 Jun 2020 00:00:00 +0000

Plasmodesma is a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them.

Source: Coursera’s Understanding Plants - Part II: Fundamentals of Plant Biology Week 1 1.7 The vacuole and plasmodesmata

URL: https://www.coursera.org/learn/plant-biology/lecture/gwRmz/1-7-the-vacuole-and-plasmodesmata

Xylem

Fri, 05 Jun 2020 00:00:00 +0000

Xylem are tubes that allows water and substances to go through a plant. They are made of cells that die through apoptosis (programmed cell death). This process thickens the side walls, remove the top and bottom ones, and progressively kills the cell, leaving a tube of all those cell walls in their place.

Source: Coursera’s Understanding Plants - Part II: Fundamentals of Plant Biology Week 1 1.8 Vascular tissue - xylem

URL: https://www.coursera.org/learn/plant-biology/lecture/jZRR7/1-8-vascular-tissue-xylem