Movement is one of the characteristic features of living organisms; it is defined as the change in place or position by the entire body or by one of its parts. There are two types of movement in animals: muscular and non muscular. Muscles and bones work together in the body for movement to occur.
As a prelude of what’s to come here’s three important points about the skeleton (which the bones of the body come together to make):
- It provides a framework for support;
- attachment for muscles and;
- protection for various organs.
Here are three important points about muscles:
- Muscles move joints and limbs when the contract.
- Every joint needs a pair of opposing muscles to make it work.
- Tendons attach muscles to bones.
Human males and females reproduce sexually. Sexual reproduction requires the combination of genetic material from two parents. This is achieved when two sex cells called gametes are brought together, This process, fertilisation, can happen either outside the female (external fertilisation) or inside (internal fertilisation).
The male sex cell is the sperm and the female sex cell is the egg. Sperms are chemically attracted to swim to egg cells. When the two sex cells fuse together the resulting combination is termed the zygote. This zygote develops onto an embryo, then a foetus, and then nine months later a baby is born. The zygote develops within the female.
The sex cells arise from the reproductive organs of the respective individual. The male reproductive organs are the: seminal vesicles, vas deferens, prostate gland, epididymis, testis and penis. The female reproductive organs are the fallopian tubes, ovaries, uterus and vagina.