internal or external division

Kingdom : Metazoa Subkingdom: Eumetazoa Division : Bilateria Grade : Eucoelomata Phylum : Arthopoda Class : Insecta Order : Orthoptera Family : Blattidae Genus : Periplaneta Species : america..

. Most of the animals are unisexual with an individual only producing either male or female gametes. The male gamete of one individual fertilizes with the female gamete of another individual to produce the zygote. The fertilisation may be external or internal..

As a result of copulation, semen containing sperms is ejaculated into the vagina. Once the semen (mixture of spermatozoa and accessory fluids) is deposited into the vaginal passage of the female, the spermatozoa start their journey through the uterus to reach the oviducts. On an average, the sperma..

>hermaphrodite . However, fertilisation is between the gametes of different individuals. Most of the animals are unisexual with an individual only producing either male or female gametes. The male gamete of one individual fertilizes with the female gamete of another individual to produce the zygote..

While the nervous system and endocrine system have their own features, they have a common method of communication. Both the systems release chemicals to communicate between cells. Together these two systems carry out a very complex process of maintaining a homeostatic (balanced) internal..

A solid has a definite characteristic shape tends to resist deformation of its shape is relatively non compressible For example, diamond Solids can be classified as: Crystalline Amorphous In a crystalline substance the solid is characterised by a very definite, well-defined ex..

Coordination in Plants - In case of plants, growth and development is in a coordinated manner. The higher plants do not show locomotion. However, locomotion is seen in structures like sperm cells of ferns and mosses that swim towards the egg. The other movements shown by the plants are associated w..

. In the presence of an external electric field, the molecules align in the direction of the electric field, and is complete when working at a low temperature and stronger electric field. The "Non-polar" is that molecule in which the centre of gravity of protons (positive charge..

If i) r>0, C divides internally. ii) r<0, C divides externally..

In rats, as in all vertebrates, sexes are separate. Male and female exhibit several differences in their external features. The Male reproductive system consists of a pair of testis that are enclosed in scrotal sacs, a pair of vas deferens, a seminal vesicle, ejaculatory duct and penis. T..