Algae, singular alga, members of a group of predominantly aquatic photosynthetic organisms of the kingdom Protista. Algae have many types of life cycles, and they range in size from microscopic to giant. Their photosynthetic pigments are more varied than those of plants and their cells have features not found among plants and <a href="https://www.britannica.com/topic/animal">animals</a>. 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 oils and as sources of food and a number of pharmaceutical and industrial products for humans The study of algae is called phycology, and a person who studies algae is a phycologist.

 The nodes in plants hold one or more leaves, as well as buds which can grow into branches (with leaves, conifer cones, or flowers. 

lymphs nodes in human body small, bean-shaped organs located throughout the lymphatic system. The lymph nodes store macrophages that can trap cancer cells or bacteria that are traveling through the body in lymph.

A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, the term is used to describe an elongated nose or snout (such as the trunk of an elephant).

A tonoplast is actually the membrane that surrounds the large vacuole in a mature plant cell.

Chlamydomonas is a genus of green algae consisting of unicellular flagellates, found in stagnant water and in damp soil, in freshwater, seawater.

Pteridophytes

The term pteron means feather. Pteridophytes have feather like or pinnate structure. They are seedless vascular plants . They have sporophytic plant body. They are also called vascular cryptogams beascuse they pocess well developed conducting system. They grow well in shady areas like forests, mountian slopes hils, etc. Pteridophytes include fern, club mosses, horse-tails. The body of pteridophytes is diffrentaited into true stem, leaves and roots like higher plants. pteridophytes do not have seeds or flowers either, reproduction takes place by production of spores inside specail structures caled sporangia. which are present on the leaves called sporophylls.

Oviparous animals lay fertilised or unfertilised eggs while viviparous animals give birth to young ones. The fertilised eggs are laid in the environment in oviparous ones while they develop into an adult orgnism within the body of viviprous organisms.