Algae

A class of eukaryotic aquatic creatures known as algae. They fall in between the two. They combine traits from both plants and animals. They resemble protozoa and fungi, which suggests that they are linked to animals. They share a connection with plants since they can perform photosynthesis. Other characteristics of both living and non-living things are present in them. Algae have a significant impact on the ecosystem. Additionally, they are economically significant to people. Phycology is the name given to the study of algae in science.
They have eukaryotic cells. This indicates that their nucleus is membrane-bound. Fewer multi-nucleated algae than single-nucleated algae make up the majority of algae. The cells have other organelles that are found in plant and animal cells. They include the mitochondria and the chloroplast. Some cellular features are unique to both plants and animals. For this reason the algae are found to be a class of organism that stands on its own.

Algae vary in sizes. There are microscopic algae and also macroscopic algae which are as long as four feet. They lack plant features such the roots, leaves and stems. Though they are photosynthetic in nature. The photosynthetic pigments are varied in algae as compared to those in plants. Algae has three photosynthetic pigments while plants have only one. The three pigments include carotenoids, chlorophyll and the phycobiliproteins.

Algae carryout cellular respiration in the mitochondria. Their mitochondria are different from those of plants and animals. The mitochondria have three different shapes in its inner membrane. The shapes are: flattened, paddled-shaped and tubular cristae. Those of plants and animals have sheetlike cristae. Another unique feature of algae is the shape and the number of DNA. The chloroplast has its own DNA same to the mitochondria. This is different from animals and plants which only have DNA in the nucleus. This DNA is circular in shape as compared to the linear nucleic DNA found in prokaryotic cells.

Algae has other organelles which single-membrane-bound such as the vacuoles; both contractile and non-contractile, lysosomes, golgi apparatus and the endoplasmic reticulum. These organelles perform various physiological functions inside the cell. The functions are secretory, transport and excretory. Enzymes are also in the cell of algae. They function to catalyze reaction inside the cells.

Classification of Algae

Algae are classified using the general taxonomic rules of classification. They belong to kingdom Protista. Algae have also been classified into groups based on their physical color. There are red, green and blue algae. The different colors of algae are due to the different photosynthetic pigments in them. Apart from the physical color, algae have been classified based on the cellular structure. This include the shapes and nature of the organelles such as the membranes. Some scientist classify algae based on their reproductive process and the cell division process. Others are classified by their nutritional process such as the storage of starch.

Reproduction of Algae.

The reproduction process in algae is varied. They reproduce through the forms of reproduction; asexual and sexual reproduction. Some reproduce sexually while others reproduce asexually. In some rare cases, algae will reproduce through both forms at the same time. Asexual reproduction involves cell division without the fusion of gametes. The specific form of cell division is the mitotic cell division. Another form asexual reproduction found in algae is fragmentation. The fragmentation results to the formation of spores.

Sexual reproduction is found in some algae. This involves the fusion of the male and female sex gametes to form a zygote. The zygote then go through the process of meiotic cell division to form a haploid organism. This means that the new organism is going to have half and equal number of chromosomes from the parent cells. The sexual reproduction in algae is dependent on the environment for its success. The environment include the temperatures, nutritional substances available and the salinity of the surrounding.

The different types of algae reproduce differently. Green algae is unique due to its ability to reproduce in both sexual and asexual forms. The red algae reproduces through the vegetative method. This is possible but not common. Due to the different forms of reproduction, different algae have different life cycles. They are three life cycle sin number; diplontic life cycle, haplontic life cycle and haplo-diplontic life cycle. Diplontic occurs cells from mitotic division while haplontic occurs in cells from meiotic cell division. Haplo-diplontic is observed in both haploid and diploid algae cells.

Importance of Algae

Algae plays an important role as an organism. It has both ecological and economic benefits. Their photosynthetic process results in production of food to the aquatic animals such as fish. The waste product of photosynthesis which oxygen is equal an important product to the aquatic-living organisms. Algae also act as shelter to some aquatic organisms such as the zooplanktons and small fish. Algae have commercial benefits. It is source of food to human beings therefore people sell it to have money. Also they have been in industries to produce fuel and fertilizers.

Work cited

Barsanti, Laura, and Paolo Gualtieri. Algae: anatomy, biochemistry, and biotechnology. CRC press, 2014.

Baweja, Pooja, and Dinabandhu Sahoo. "Classification of Algae." The Algae World. Springer Netherlands, 2015. 31-55.