Growth

Japanese Blood Grass

Japanese bloodgrass (Imperata cylindrica), like all species of grass, is a member of the Poaceae family, also known as the Gramineae family. Grass, like most plants, needs three things in order to grow and survive: sunlight, water and nutrients (Harris, 2002).

In order to collect as much water and nutrients as possible, grass’ fibrous roots grow down into the earth, spreading out in different directions like fingers. The wide spread of the root system also helps to keep the grass secured to the ground (Harris, 2002). In the case of the Japanese bloodgrass, as much as 60% of the plant’s biomass consists of the rhizome root systems beneath the soil (Sellers et. al., 2002). This rhizome root system also helps the bloodgrass grow larger. The rhizomes are dense, preventing other plants from taking room in the same area as the grass. They also have sharp tips, which can pierce through the roots of other plants and trees, allowing the root system to continue to grow larger. (Pillion, 2017).

The red colour of the blades gives the bloodgrass its name (image from Wikimedia Commons)

The root systems also help the bloodgrass to thrive after wildfires. The bloodgrass burns far hotter than other plants, causing rapid-spreading wildfires at a temperature which can kill trees and other plants. While the grass above the soil burns, the roots system beneath remain unharmed. After the wildfire the tops of the plants grow back quicker and greenerwhile the roots begin to spread to areas previously occupied by now-destroyed trees and plants, allowing the bloodgrass plant to expand. The destruction of trees is particularly beneficial to the grass, as it exposes it to more sunlight. (Pillion, 2017).


Brewer’s Yeast

Brewer’s yeast (Saccharomyces cerevisiae), like all species of yeast, is a single-celled fungusIn order to grow, yeast must consume carbon-containing compounds. It can consume a wide variety of mono-, di- and trisaccharidesbut shows preference for glucose and fructose over other sugars (Broach, 2012). Yeast digests glucose through the process of fermentation, in both aerobic and anaerobic conditions, producing carbon dioxide and ethanol: 

C₆H₁₂O₆    →     2CO₂     +    2 C₂H₅OH     (+2ATP)

For every molecule of glucose digested, two molecules of ATP are produced. ATP is then converted to ADP through a hydrolysis reaction, releasing which can be used in the yeast’s cellular processes, including growth (Scitable, 2014). 

The carbon dioxide produced through yeast fermentation causes bread to rise (image from Pixabay)

Also required for the growth of yeast is oxygen (Battcock and Azam-Ali1998). Oxygen is not always necessary for the fermentation of sugarssome species of yeast can carry out the process without it—but it is essential for the organism’s growth. 


References

Battcock, M and Azam-Ali, S (1998) Fermented fruits and vegetables: a global perspective, Rome, Daya Publishing House

Broach, J B (2012) ‘Nutritional control of growth and development in yeast’, Genetics, 192(1), 73-105

Harris, T (2002) How grass works. Available at:  https://home.howstuffworks.com/grass.htm (Accessed 03 December 2019)

Pillion, D (2017) This ‘vicious’ invasive plant burns hot enough to kill trees and stabs them with its roots. Available at: https://www.al.com/news/2017/08/this_invasive_plant_is_sending.html (Accessed 03 December 2019)

Scitable (2014) ATP. Available at: https://www.nature.com/scitable/definition/atp-318/ (Accessed 02 December 2019)

Sellers, B A et. al. (2002) Cogongrass (Imperata cylindrica) biology, ecology, and management in Florida grazing lands’, University of Florida, SS-AGR-52/WG202

Bibliography

En.m.wikipedia.org. (2019). Imperata cylindrica. [online] Available at: https://en.m.wikipedia.org/wiki/Imperata_cylindrica [Accessed 26 Nov. 2019]. (Figure 1 Reproduction)

En.m.wikipedia.org. (2019). Rhizome. [online] Available at: https://en.m.wikipedia.org/wiki/Rhizome [Accessed 26 Nov. 2019]. (Figure 2 Reproduction)

Encyclopedia Britannica. (2019). Vegetative reproduction | horticulture. [online] Available at: https://www.britannica.com/science/vegetative-reproductioN [Accessed 26 Nov. 2019].

Encyclopedia Britannica. (2019). yeast | Definition & Uses. [online] Available at: https://www.britannica.com/science/yeast-fungus#ref609507 [Accessed 10 Nov. 2019].

Funscience.in. (2019). BUDDING. [online] Available at: http://www.funscience.in/study-zone/Biology/AsexualReproduction/Budding.php [Accessed 15 Nov. 2019]. (Figure Reproduction)

Grasses, C. and Grasses, C. (2019). Care Of Japanese Blood Grass: Tips For Growing Japanese Blood Grasses. [online] Gardening Know How. Available at: https://www.gardeningknowhow.com/ornamental/foliage/japanese-blood-grass/care-of-japanese-blood-grass.htm [Accessed 6 Nov. 2019].

Micropop.cbs.umn.edu. (2019). Multicellular Yeast Primer | micropop. [online] Available at: http://micropop.cbs.umn.edu/projects/multicellular-yeast/multicellular-yeast-primer.html [Accessed 29 Oct. 2019].

Study.com. (2019). [online] Available at: https://study.com/academy/lesson/asexual-plant-reproduction-vegetative-propagation-and-bulbs.htmL [Accessed 16 Nov. 2019].

Vedantu.com. (2019). Budding – Types of Budding | Budding in Yeast and Budding in Hydra. [online] Available at: https://www.vedantu.com/biology/budding [Accessed 25 Nov. 2019].

Reproduction of Japanese Blood Grass

Reproduction Process for Japanese Blood Grass

 

Japanese blood grass (Imperata cylindricais banned in half of the states in the United States due to its invasive nature. If Japanese blood grass is allowed to revert back it it’s green state (before it turns the iconic blood red state) then it takes its more aggressive form and spreads via its rhizomes through a series of stem-like networks underground, allowing it to take over areas vast areas of land.

Figure 1 Reproduction – Imperata cylindria ‘Red Baron’, a strain of Japanese Blood Grass

Rhizomes are a horizontal underground root system that store starches and proteins. As such it enables them to survive a throughout unfavourable weathers and seasons as they reproduce underground. (Encyclopedia Britannica. 2019)

The modified stems reproduce asexually, also known as vegetative reproduction. This occurs when the horizontal stems develop new vertical stems at critical points.

Rhizomes grow outwards, invading into nearby soils and allows them to develop a new network of vertical stems and horizontal stems.

This type of reproduction creates an invasive plant such as Japanese Blood Grass to become such a nuisance plant.

Figure 2 Reproduction – Picture of a rhizome network.

Reproduction of Brewers Yeast

Reproduction Process for Brewers Yeast

How does Brewers Yeast Reproduce?

Brewers Yeast (Saccharomyces cerevisiae) is a unicellular fungus that reproduces asexually through a budding process in which cells are replicated using mitosis (cell division). (Micropop.cbs.umn.edu. 2019)
Budding occurs in most yeasts, in this process small growths form at the end of the the mother cell. The mother cell shares its cytoplasm with the growth and uses mitosis to split its nucleus, allowing both the growth and mother cell to have its own nucleus. The mother cell is able to reproduce many growths at one time, sharing it’s cytoplasm and dividing its nucleus over and over again. Once the growth develops to a certain point before it detaches it is also capable of budding by using the same process and this can cause a chain of cells to be produced. Eventually the buds will detach themselves from the mother cell and these become individual yeast cells.

Figure Reproduction – Diagram of the budding process in yeast. (Funscience.in. 2019)