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A. Growth and Development of Organisms
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A.Growth and Development of Organisms
What kind of changes happen to animals during their life? Compare the changes that happen to a chicken and a butterfly. Both animals change differently as they grow. Which animal appears to change more? Have you ever observed the changes that happen to a corn seed as it grows? If you compare the germinating phase and the maturing phase that follows, which phase shows more growth, or which phase changes more? . Every organism experiences changes during its life. The changes include changes in size, a small one becoming larger, a short one becoming longer, a light one becoming heavier, and so on.
Growth is an increase in size of an organism. It is a quantitatively measurable change. For example, leaves increase in length and width. It means that the length and width of leaves can be measured in centimeters or meters. We can say that they grow.Another change observable in the previous observation was the change of a seed that sprouted into a seedling. Such a change belongs to both growth and development.
A frog starts its life cycle as a zygote from a fertilized egg. The egg then hatches and a tadpole comes out. A tadpole is able to swim to find food. It continues to grow and then change shapes. The growth starts with limbs (or legs), lungs, and teeth that grow inside the mouth. Changes that will support the tadpole’s life on land begin at this time. 
What happens to the tail of a tadpole? After its limbs grow, the tadpole does not need a tail to move about. Does the tail come off the body? It does not. It becomes smaller and smaller so that it gradually merges withs the body of the young frog. After a few months the body of the young frog has completed its metamorphosis process. Metamorphosis is the change of an organism in one life cycle. When the metamorphosis is completed, the animal gains its adult shape. The pattern of change is complete and the cycle may occur in any new individual
of the species.
Butterflies are actually adult forms of organisms that have experienced a complete metamorphosis through the phases of being a larva, a pupa, and an imago (adult individuals) At a given moment a larva becomes inactive and it is called a pupa. In this phase pupa has a coccoon. The pupa changes into an adult butterfly in a completely different shape. It does not look like a caterpillar anymore.
Some organisms can resist extinction because they reproduce and can adapt well. Various changes may occur during the process of producing a new generation. An alternating succession from one generation to another generation many change physically different characteristics occurs in some organisms. This process is called metagenesis.
B. Metagenesis More
Growth is an increase in size of an organism. It is a quantitatively measurable change. For example, leaves increase in length and width. It means that the length and width of leaves can be measured in centimeters or meters. We can say that they grow.Another change observable in the previous observation was the change of a seed that sprouted into a seedling. Such a change belongs to both growth and development.An example of development is the change that happens to an adult hen. When it reaches its reproductive phase, it has the capacity to lay eggs. There is no increase in its physical size but there is an important change in the hen’s life: its reproductive capacity. In the developmental process, the change that happens is called a qualitative change, which cannot be measured. When an egg is about to hatch, there is no increase in its size but there is an important process of development: the egg hatches. See also Figure showing a newly-born butterfly coming out of its cocoon.
Some Factors that Influence Growth and Development
Growth and development of living thing are influenced by various factors, booth external and internal. Factor are from inside the body of the organism and from the environments.
The internal factors are coming from inside the body. There are determined by genes. The work of genes is seen in the work of hormones and enzymes. A hormone, auxin, for example increases the number and the size of the cells of a tree trunk. It causes the tree grow taller and bigger. An enzyme for example, digestive enzymes in mammals enable food to be digested and a bsorbed by the body. The absorbed food is used to compose new cells to grow and develop.
Environmental factors are related to anything in the environment such as air, water, soil, and sunlight. The sunlight plays an important role in the growth and development of plants. It affects quantity of chlorophyll, formation of young plants, period of fruition, and the ability to form and store food.
The organisms consist mostly of water. Water is a solvent, or a substance that dissolves various other substances. All nutrients can be utilized by the body of organisms because they dissolve in water. Similarly, all substances that must be disposed from the body must also be soluble, or able to dissolve, in water.
Growth of animals
Animals are performing growth during their life cycle. Their life cycle starts from their birth, and then continues to grow, mature, produce and die.
Animals need food for their growth. Food gives them with energy to grow. But there are animals that do not move, for example, corrals that cling to rocks for the rest of their life.
Based on their food, animals can be classified into three groups, namely herbivorous, carnivorous, and omnivorous. Animals’ foods normally consist of organic materials.
Below are some examples of animals’ growth and development processes.
Metamorphosis
Metamorphosis
Some animals such as butterflies and frogs undergo metamorphosis phases of different appearances. Figure 1.4 illustrates the metamorphosis phases of a frog.
A frog starts its life cycle as a zygote from a fertilized egg. The egg then hatches and a tadpole comes out. A tadpole is able to swim to find food. It continues to grow and then change shapes. The growth starts with limbs (or legs), lungs, and teeth that grow inside the mouth. Changes that will support the tadpole’s life on land begin at this time. What happens to the tail of a tadpole? After its limbs grow, the tadpole does not need a tail to move about. Does the tail come off the body? It does not. It becomes smaller and smaller so that it gradually merges withs the body of the young frog. After a few months the body of the young frog has completed its metamorphosis process. Metamorphosis is the change of an organism in one life cycle. When the metamorphosis is completed, the animal gains its adult shape. The pattern of change is complete and the cycle may occur in any new individual of the species.
Butterflies are actually adult forms of organisms that have experienced a complete metamorphosis through the phases of being a larva, a pupa, and an imago (adult individuals) At a given moment a larva becomes inactive and it is called a pupa. In this phase pupa has a coccoon. The pupa changes into an adult butterfly in a completely different shape. It does not look like a caterpillar anymore.
Grasshoppers have different types of a metamorphosis . Their metamorphosis is incomplete and it involves three phases, namely egg, nymph, and adult.
Nymph are smaller than that of an adult grasshoppers but it has no wings . But on the whole they have the shape as adult grasshoppers . Gradually the wings and a system of reproduction keep growing until they are fully ready to continue their life cycle. They mate and reproduce young grasshoppers of their own. Another animal that has an incomplete metamorphosis is a mosquito .
Some organisms can resist extinction because they reproduce and can adapt well. Various changes may occur during the process of producing a new generation. An alternating succession from one generation to another generation many change physically different characteristics occurs in some organisms. This process is called metagenesis.
