THE STAGES OF LIFE
Throughout life, the human body is constantly changing as it experiences different stages of development. From a single cell, the body goes through a process of cell division and multiplication as it grows and develops. By adulthood, the body is fully grown, and the cells no longer divide for growth. Instead, they divide to replace worn out or damaged cells.
HOW CELLS MULTIPLY
We each start out as a single cell. To develop different organs and tissues for the body to grow, our cells must multiply. As adult, cells need to be replaced when damaged or when they complete their life cycle.
Mitosis
The body produces new cells by a process called mitosis. This is when a cell's DNA, which carries all the instructions to build and run a new cell, duplicates itself. The cell then splits to form two identical cells. This is how cells grow - by making exact copies of themselves.
1) CHECKING: The parent cell gets ready for mitosis. It checks its DNA for damage and makes any necessary repairs.
2) PREPARATION: The chromosomes duplicate themselves, then the originals join together with their copies.
3) LINING UP: Each doubled chromosome attaches to special fibers, which help them to line up in the center of the cell.
4)SEPARATION: The chromosomes break apart at the point where they were attached. Each half is pulled to the opposite end of the cell.
5) SPLITTING: A membrane forms around each group of the chromosomes. The cell membrane starts to pull apart to form the two cells.
6) OFFSPRING:Two daughter cells are formed. Each one contains a nucleus with an exact copy of the DNA from the parent cell.
FUN FACT!!
USE IT ON LOSE IT
The speed of aging varies widely between people. Although genetics plays its part, evidence suggests that keeping both mind and body active can help to slow down the aging process and may help you live longer.
Staying active
BRITON FA UJA SINGH holds many senior running records, including marathons. In 2013, he ran in the Mumbai Marathon at the age of 102.
THE CHANGING BODY
From babyhood to old age, the body changes as it grows and ages. At the age of around 20 - 30 humans reach maximum height and are physically at their strongest. After that, the body very gradually decreases in power with age. However, the brain actually continues to improve over several more years. As it gains more experience, it gets better at analyzing situations and making decisions.
FUN FACT!!
ONLY A FEW BODY CELLS LAST A LIFETIME - THEY INCLUDE NEURONS IN THE BRAIN AND HEART MUSCLE CELLS.
Making a man
Here are the stages of life for a human male, from a baby to an elderly man. Size and height are the most obvious changes, but there are many other changes on the way to adulthood and an old age
1)BABY
Babies have a large head and short arms and legs. By around 18 months, they have gained enough strength and muscles control to stand and start to walk.
2)TODDLER
At about age 2, the arms and legs close so the head no longer looks as large. The brain develops rapidly, and children learn to talk and use their hands with more precision.
3)CHILD
From the ages of 5-10, children continue to grow and learn complex physical skills such as riding a bike and swimming.
4)TEENAGER
During puberty, hormones trigger major changes: height increases, the body takes on more adult features, and emotional swings are common.
5)YOUNG ADULT
The body reaches its adult height, and bones stop growing. People are physically capable of reproducing - having children.
6) ADULT
Humans are physically strongest between 20 and 35 years of age. Muscle development is complete and body systems continue to function well.
7) MIDDLE - AGED ADULT
Between the ages of 50 and 70, the skin becomes less stretchy and wrinkles appear. Muscles weaken. Vision and hearing begin to deteriorate.
8)ELDERLY ADULT
A person gets shorter as they age because their spine shortens. Their muscles also get weaker, and together with stiff joints this can make movement slower.
👍👍
You must be logged in to post a comment.