Structural features and structure of chlamydomonas

Chlamydomonas is a unicellular organism, the distinguishing feature of which is the presence of two apical flagella. This is a kind of green algae that lives in stagnant water and on moist soil, as well as in fresh or sea water. The structure of chlamydomonas has a number of features. Among them, ion channels that are activated by direct exposure to light, as well as a red photosensitive eye and a complex regulatory system.

Chlamydomonades: general information

By type of nutrition, most species are obligate phototrophs. But some refer to optional heterotrophs, which can grow in the dark, using acetate as a source of carbon. According to their morphology, these mobile unicellular algae, as a rule, are oval in shape. The cell wall consists of a glycoprotein. Chlamydomonads multiply both sexually and asexually.

In total there are about 150 species. Chlamydomonas actively multiplies in a humid environment, as well as in waters rich in ammonium compounds. Features of the structure of chlamydomonads include the presence of pigments. Muddy green color of water in standing water bodies is due to the presence of thousands of these flagelliform microorganisms. Bright red pigment in one of the species helps to color the habitat in scarlet or pink. Some species are found in the most unexpected locations, for example, in salt water.

Structure of chlamydomonas

In the cervical spine are two flagella, originating from the basal grain, located in the cytoplasm. At their base there are contractile vacuoles. The structure of the chlamydomonada cell presupposes the presence of a cup-shaped chloroplast, where the cell nucleus is located. Here, photosynthesis products form starch, as well as protein, surrounded by starch grains. The eye in the form of a spot is present in the anterior part of the chloroplast. It consists of two or three more or less parallel rows of linearly organized drops of fat.

Features of the structure

In its vegetative stage the organism has a very simple structure. Its size varies within 0,02 mm. Each cell has a spherical, ellipsoidal, cylindrical or pear-shaped shape. They tend to taper at the front end. The structure of chlamydomonas includes a thin cell outer wall, two flagella, and two contractile vacuoles responsible for respiration and excretion. Orange-red pigment or eye (stigma) is in the thickness of the cell wall and performs the function of primitive vision, since it is very sensitive to light. In some species, there may be two or three eye patches. In the wide part of the body in the cytoplasm there is a large cup-shaped chloroplast, inside which the nucleus is located.

How does the structure of the cell change during asexual reproduction?

The structure of chlamydomonas undergoes some changes during cell division. Asexual reproduction occurs in the following way: when creating favorable conditions zoospores are formed, the cell becomes immovable, the flagella hide or are discarded, and the contractile vacuoles also disappear, the protoplast is divided longitudinally into two parts, each of which, in turn, is divided into 2 parts. Thus, any cell produces from 2 to 16 similar structures. Gradually, young individuals develop all the structures characteristic of green algae: flagella, vacuoles and so on. Each of them develops into a new plant. This separation process is repeated every 24 hours. Thus, by the end of the week about two million individuals are formed from one parent plant.

Features of sexual reproduction

During sexual reproduction, the cellular protoplast is divided into 16, 32 or even 64 flagellated gametes, which can be uncovered or enclosed in a cell wall. The sex cells merge into pairs, forming a zygote. As a result, it rounds, seizes flagella, forms a thick wall around the cytoplasm and sinks to the bottom of the reservoir for further development. In this form, it is resistant to temperature changes and will survive, even if the reservoir dries. Zoospores and gametes are morphologically similar. They differ only in size and behavior. This difference arises from a larger number of subdivisions of the mother cell during the formation of gametes. Thus, small individuals lose their ability to live independently.