Test: Plant Kingdom - September 24, 2022 - NEET MCQ

Plants are sub-classified based on their well-differentiable structure, presence of vascular tissues, presence of seeds, seed coat i.e. if the seeds are naked or covered.

Plants are classified as Thallophyta and others based on their well differentiable structure. Plants whose structure can’t be differentiated are put under the category of “Thallophyta”.

Ulothrea are multicellular autotrophic algae. Chlamydomanas is an example of unicellular algae. Chlamydomanas have flagella to promote their movement. Spirogyra attains its name because of spiral like arrangement of chloroplasts.

Ulva is a multicellular algal that grows on moist rocks and walls. It is edible and is used as salad leaves. It is also called as sea lettuce. It has 2 layers of irregularly arranged cells.

Volvox grows in colonies. The structures that connect them are called cytoplasmic bridges. Daughter colonies of volvox grow inside the parent colony. They contain flagellum that facilitates their movement.

Spirogyra contains two cellular layers. The outer cellular layer is made of Pectin. The inner cellular in spirogyra is made up of Cellulose. This double cellular layered structure helps them to withstand osmotic pressure.

Ulothrea are multicellular filamentous algal. Ulothrea contains three different sets of cells i.e. apical, basal and lateral cells. Apical cells are rounded at one end whereas basal cells are elongated at one end. Every cell contains chlorophyll except basal cell contains chlorophyll in them.

Chladophora is a filamentous branched algal. Chladophora is also called river weed in some areas. It is edible. There are many different varieties of chladophora that are difficult to be classified. Ulva are also called as sea lettuce since they are used in salads.

In fragmentation, a parent organism breaks into a fragment and each fragment gives a new individual. Spirogyra uses fragmentation to reproduction.

During unfavourable conditions, an outer layer that is formed outside chlamydomonas is called cyst. These unfavourable conditions allow multiple fission inside the cyst.