why do we look at green algae in a botany course?

Green algae and land plants usually appear green because abundant chlorophylls a and b are not concealed by large amounts of differently colored accessory pigments.

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What do you learn about algae?

You will also explore the vast diversity of algae including the characteristics and applications of some of the main types of algae that are in commercial use today. Later you will learn about algal ecology and how interactions with environment, including pests and predators, affect algal productivity.

Why is green algae important to humans?

Some green algae are particularly useful to humans in open 'oxidation ponds'. Ponds between 1 m and 1.5 tn deep receive raw sewage, and oxygen provided by algal photosynthesis is vital for the other aerobic microorganisms that utilize the sewage. Many green algae synthesize antibiotic substances.

What are the salient features of Chlorophyceae (green algae)?

1. Salient Features of Chlorophyceae (Green Algae): The Chlorophyceae or the green algae are characterized in having grassgreen-coloured chloroplasts containing the photosynthetic pigments, chlorophyll a, chloro­phyll b, carotenes and xanthophylls of which the first two predominate over the others.

Where can I find images of the algae seen in class?

Images of the algae seen in class are available on the lab computer for review. It is not advisable to rely upon web images to study for the lab exam because these are often different species and sometimes misidentified. You are welcome to come to lab outside of regularly scheduled class hours (no other class uses the room).

Why do we study algae in botany?

In addition to their ecological roles as oxygen producers and as the food base for almost all aquatic life, algae are economically important as a source of crude oil and as sources of food and a number of pharmaceutical and industrial products for humans.

Why is green algae so important?

They play a vital role in aquatic ecosystems by forming the energy base of the food web for all aquatic organisms. As autotrophic organisms, algae convert water and carbon dioxide to sugar through the process of photosynthesis.

What is algae in botany?

Algae are a diverse group of aquatic organisms that have the ability to conduct photosynthesis. Certain algae are familiar to most people; for instance, seaweeds (such as kelp or phytoplankton), pond scum or the algal blooms in lakes.

Why do scientists evolve plants from green algae?

Algae do not keep the embryo inside of themselves but release it into water. This was the first feature to evolve that separated plants from green algae. This is also the only adaptation shared by all plants. Over time, plants had to evolve from living in water to living on land.

How can the study of algae determine the health of the marine environment?

As previously mentioned, the presence of algae in the ocean—usually near the surface where they can absorb the sun's energy—helps contribute to a healthier ocean. One way that they do this is by using up the carbon dioxide from the atmosphere to produce and release oxygen back into the atmosphere.

Why algae are included in plants?

Why are algae considered plant-like? The main reason is that they contain chloroplasts and produce food through photosynthesis.

What characteristics do green algae share with plants?

Green algae contain the same carotenoids and chlorophyll a and b as land plants, whereas other algae have different accessory pigments and types of chlorophyll molecules in addition to chlorophyll a. Both green algae and land plants also store carbohydrates as starch.

Is green algae a plant?

The "green algae" is a paraphyletic group because it excludes the Plantae. Like the plants, the green algae contain two forms of chlorophyll, which they use to capture light energy to fuel the manufacture of sugars, but unlike plants they are primarily aquatic.

Which group of algae do scientists think that plants evolved from?

The evidence suggests that land plants evolved from a line of filamentous green algae that invaded land about 410 million years ago during the Silurian period of the Paleozoic era.

Did all land plants evolved from green algae?

But it wasn't until the rise of technologies that allowed for more accurate genetic mapping that we could demonstrate that all land plants did in fact evolve from green algae. So, all lands plants, from flowers to fruits to towering trees, all evolved from a slimy green cluster of microorganisms.

When did green algae first evolve?

The oldest green seaweed on record, the ancestor of all land plants, lived about 1 billion years ago, a new study finds. Scientists have discovered the fossils of what may be the oldest green algae ever known. The newfound seaweed — called Proterocladus antiquus — lived about a billion years ago.

What is green algae?

The green algae are the members of the Division Chlorophyta are commonly known as green, due to the presence of chlorophyll a and b, which convey them bright green colour. Their cells are similar to higher plants in the presence of a well-defined nucleus, photosynthetic pigments localized in chloroplasts, food reserve commonly stored as starch, ...

Where do green algae grow?

Where the green algae grows? Green Algae. More than 90% of species grow in fresh water and the remaining 10% are the marine forms. The freshwater species are cosmopolitan in distribution, commonly inhabiting permanent or semi-permanent pools, lakes, ponds, etc. The marine species mainly occur in the tropical sea.

What causes red rust on tea leaves?

Cephaleuros is parasitic and causes red rust disease of tea leaves. Some species occur in unusual environments; for example Chlorella has some thermophilic species, found in hot springs, and Chlamydomonas yellowstonensis occurs on snow covered tops of mountain.

What are the main asexual spores?

Akinetes, zoospores and aplanospores are the main asexual spores. Sexual reproduction may be isogamous, anisogamous or oogamous. The zygote or oospore secretes a thick wall and undergoes a resting period. It germinates under satisfactory conditions. Go for ►►. Brown Algae.

What is chlorella used for?

For example, the use of Chlorella in research on photosynthesis has been fulfilling. They are also used in ion uptake experiments and were important in early work on the structure of tell walls and flagella. Some green algae are particularly useful to humans in open 'oxidation ponds'.

What are the characteristics of unicellular algae?

Unicellular algae show characteristics of a typical higher plant cell and often make ideal research material since they can be grown in large numbers under precisely controlled conditions without occupying a great deal of space. For example, the use of Chlorella in research on photosynthesis has been fulfilling.

What are the organelles of green algae?

The cells of the green algae have mitochondria, Golgi bodies, ribosomes, ER, plastids and other cell organelles. The main pigments of Chlorophyceae are chlorophyll a and b but a-and P- carotenes; and xanthophylls are also present. The pigments are found in the lamellae of the well-organized chloroplast. The shape of the chloroplast shows much ...

Why do we care about green algae?

Well, we care about green algae, because several of them are already used as food today. This is just a picture of two. One is Chlorella. This is a small green algae, very, very fast growing, and it's found in a lot of different foods today.

Why is green algae important?

So, one of the reasons that we study green algae, and one of the reasons that they're going to become more important in the future is that they're a very good source of food.

How many genomes are there in green algae?

So, as I said, green algae, their genomes are quite well understood. So, there's three genomes. There's a chloroplast genome, and that's a small circular genome, we'll talk about that in another class. There's a nuclear genome that has chromosomes much larger, almost 100 times larger than the chloroplast genome.

What is the motile algae that swims around?

So, that's always a major component of the cell. This happens to be a picture of a green algae Chlamidomonas reinhardii. That is a motile algae, so there are two flagella, so it's capable to swim around. It has something called a pyrenoid, that contains the carbon fixing enzyme, RuBisCO.

How many kilobases are in an algae genome?

In some algae, the mitochondrial genomes are as small as 15 kilobases, and in other algae they can be upwards of 600 to 700 kilobases. Importantly, in several green algae all three of those genomes are transformable.

What is the division of algae called?

So, quite literally, they are green colored algae. They come from a division of algae called the Chlorophytes and the Charophytes. And this is also the division that higher plants come from. So, as we'll show you in just a minute, green algae and higher plants are very closely related.

Why is green algae the same as terrestrial algae?

In fact, one of the reasons that we studied green algae for many many years is because the photosynthetic complexes were identical between green algae and terrestrial crop plants that we use to produce food.

Why are algal cultures important?

Algal cultures are essential when conducting competition studies, bioassays, assessment of zooplankton food preferences, and determination of algal life histories. They are also necessary for molecular systematic work. Algal cultures may be "unialgal," which means they contain only one kind of alga, usually a clonal population ...

What can be added to the growth medium to discourage cyanobacteria?

It is best to begin with young branches or filament tips which have not yet been extensively epiphytized. Antibiotics can be added to the growth medium to discourage growth of contaminating cyanobacteria and other bacteria. Addition of germanium dioxide will inhibit growth of diatoms.

What is BBM in algae?

Freshwater Growth Media used in this class: 1) BBM is Bold's basal medium, chemically defined; good for many green algae. 2) Soil-water is undefined and used for algae whose nutritional requirements are unknown, or which will not grow on simple inorganic media.

Is SD11 a good medium for algae?

3) SD11 is a defined medium that is somewhat more complex than BBM; it contains a vitamin mixture. Good for many green algae.

How to lock up a lab before leaving?

You will be informed of the location of a key to the lab (but be careful to return the key, and to lock up the room before you leave the lab). 1) Bring your copies of Graham, Graham, Wilcox and Cook, and Prescott to lab each time, or leave them in your cabinet. 2) Treat microscopes well. Rotate microscope objectives to low power before removing ...

How to remove excess liquid from a culture?

Remove excess liquid with a tissue, so that the cover slip is not floating. If cultures are on agar, heat a loop to glowing cherry red in the flame of an alcohol lamp. Let the loop cool, then retrieve a little algal material and place in a drop of water on a slide, adding cover slip.

Can you use web images to study algae?

Images of the algae seen in class are available on the lab computer for review. It is not advisable to rely upon web images to study for the lab exam because these are often different species and sometimes misidentified.

Do cyanobacteria outperform green algae?

The dogma surrounding carbon assimilation has it that, due to their highly effective CO2-concentrating mechanisms, cyanobacteria will always out-perform, for example , green algae where inorganic carbon is in short supply. Working on the cyanobacterial genus Microcystis, Ji et al. (2017) now suggest this might not always be true, with possible improved performance with rises in atmospheric (and hence dissolved) CO2. Many cyanobacteria form extensive toxic blooms that present significant health risks and economic costs: how they will react in a future world with elevated CO2and temperature is thus of intense interest for water management.

Do cyanobacteria have higher CCM activity?

In general terms, and as a consequence of the lower affinity of their Rubiscos for CO 2, cyanobacteria tend to show higher expression of CCM activity (based on internal:external CO 2 concentration ratios) compared to green algae and this, together with observations of preferences of cyanobacteria for high pH environments where the proportion of CO 2 relative to bicarbonate is low, is taken as suggesting a greater competitive ability by cyanobacteria when CO 2 levels are low. As pointed out by Ji et al. (2017), there is some evidence for this from ecological observations ( Shapiro, 1990, 1997) as well as previous competition experiments with freshwater phytoplankton communities ( Low-Décarie et al., 2011, 2015 ), though Caraco and Miller (1998) caution that high pH could be as important a driver to the competitive success of cyanobacteria as CO 2.

Do green algae compete with cyanobacteria?

It would be interesting to see how the competition between green algae and cyanobacteria would work out with cyanobacterial species/strains expressing higher affinity transporters such as SbtA or BCT1. The work of Sandrini et al. (2016) and Ji et al. (2017) implies that as the DIC concentrations in the water column change, we are likely to see different strains of cyanobacteria, expressing different transport systems, appearing and disappearing, with strains such as the Microcystis bicA strain used by Ji et al. becoming more dominant as atmospheric CO 2 levels continue to rise. Although past studies have implied that elevated CO 2 is likely to stimulate growth of green algae and other species such as diatoms or Chrysophytes with a lesser (or no) CCM activity (as reflected in internal:external CO 2 concentrations) compared to cyanobacteria, it may well be that instead, all other things being equal, we will see a dominance of different cyanobacterial strains filling a succession of niches with varying conditions of alkalinity, pH and CO 2 /HCO 3– concentrations. Certainly such niche exploitation by different strains of cyanobacteria is used, for instance, in Cylindrospermopsis raciborskii ( Burford et al., 2016) and Microcystis ( Kardinaal et al., 2007) in relation to light availability.

Why are algae blooms important?

Algal blooms are a naturally occurring phenomenon, and are essential for a lake to stay healthy. This excess bloom of plant life provides tons of food for other microorganisms and fish. The algae convert the free floating nutrients into a form edible (the algae themselves) by the other residents of the lake.

Why do algae bloom?

These blooms occur because conditions become just right in the lake, and one species of algae begins to reproduce at an astounding rate . These algae are able to reproduce because there is an excess ...

What is the pigment that allows plants to photosynthesize sunlight into food?

Chlorophyll is the essential pigment that allows plants to photosynthesize sunlight into food. (Photosynthesis is another story for another day). So, in your lake you have these little single celled plants floating around soaking up the sun and pulling nutrients from the water.

What is the pigment that makes plants green?

These tiny little micro-organisms live off of the nutrients in the lake and use the sunlight to photosynthesize, much like the plants and trees above the water. These little organisms contain large amounts of “chlorophyll.”, which is a pigment that makes all plants green. Chlorophyll is the essential pigment that allows plants to photosynthesize ...

Why is the red tide called the red tide?

A red tide is an algae bloom that occurs in the ocean, it is called a red tide because of the coloration of the algae found in the oceans, which are generally brown to red. When a lake has a particularly large algal bloom, and the water becomes very murky and green, bad things can start to happen.

What is a harmful algal bloom?

Algal blooms are a natural thing indeed, but scientists have also observed some troubling events that they have classified as “Harmful Algal Blooms” or HAB’s for short. An HAB, simply put, is a bloom that is damaging to the ecosystem of the lake or its inhabitants.

What is the algae in the ocean?

Algae can range from the microscopic single celled organisms that can be floating in a lake, to the “seaweed” that is found in the oceans, like the Giant Kelp ( macrocystis pyrifera) plant. Your typical lake variety of algae is known as “ Green Algae.