Lysosomes: Types and Functions
They were first of all observed by Christian de Duve in 1955. The lysosomes are tiny vesicles which are bounded by single membrane and are...
Darwin’s theory of evolution (Theory of Natural Selection)
It is also known as theory of natural selection. Charles Robert Darwin was (1809- 1882) an English naturalist published his famous book “ The origin...
Differences between Acraniata and Craniata
S.N Acraniata Craniata 1. They are exclusively marine. They are aquatic or terrestrial. 2. They are small sized chordates. They are mostly large sized...
Symmetry in animals
Introduction Symmetry means the arrangement of body parts into geometrical designs. Many adult sponges that are irregular in shape are said to be asymmetrical. However,...
Amphibious adaptations
Introduction of Amphibians Amphibians are the first group among the chordates that live outside water. Several new features for terrestrial life also developed in amphibians....
Mosquito and its life cycle
Introduction Mosquitoes are two-winged flying insects that suck blood from humans and other animals. They are found all over the world but are mostly common...
Lifecycle of silkworm and sericulture
Introduction The silkworm is the larva or caterpillar or imago of the silk-moth that produces silk thread. The thread is used for making silk clothes...
Aquatic animals and their adaptational characteristics
Introduction Any change in an organism that makes it slowly or rapidly better suited to the environment is called adaptation. It can also be defined...
Protozoans and its classification
The word Protozoa is derived from two Greek words: protos means first; zoon means animal. They are the first animals with a protoplasmic grade of...
Classification and characteristics of Superclass: Tetrapoda
Tetra-four, podos-feet Primarily terrestrial, some are secondarily aquatic. Two pairs of pentadactyl limbs. Body covered by an exoskeleton of epidermal hair, feathers or scales. Lungs...