Growth and Development

A. Understanding Growth and Development
Growth is a process of accretion size, good volume, weight, and number of cells that are irreversible (can not return to the origin). Meanwhile, the development or differentiation of cells is a change towards a more mature.
Growth and development has a very important meaning for living. For example, in humans, to grow and be able to survive and preserve their offspring. When I was a baby, toddlers, and young children, the human body has the durability is still weak so susceptible to disease. But, having grown and developed into a mature, stronger immune systems so that their survival is guaranteed.
Human growth and development to bring to maturity. As adults, people can produce offspring that human populations will be safeguarded its preservation. Now, you try to imagine if there is no growth and development in humans? Perhaps the human population will become extinct. So also with animals and plants. If animals and plants do not experience growth and development, it will become extinct.
In plants, these developments result in a variety of tissues and organs of plants. Growth and development in animals berbedabeda between one species with the other species. But, basically have similar developmental stages, as follows.

    P embelahan Tues
After fertilization (conception of male gamete cells and female gamete cells), forming a zygote. Zygotes undergo mitotic continuously. Cleavage takes place very rapidly. The cells resulting from division called morula. Morula developed into a hollow called the blastula.

    Morphogenesis
Blastula continue to undergo cell division. During this cleavage occurs morphogenesis, the process of development of the various parts of the body form the embryo.

    Differentiation
Blastula continue to divide and form a gastrula. From gastrula embryo is formed. Developing embryonic cells continue to form tissues, organs, and organ systems that make up the structure and functions that will be enabled on into adulthood.

    Growth
Once formed organ, there was growth of living things become larger. The development goes hand in hand with growth. The development is a process of reaching maturity. The difference between growth and development, the growth can be measured with a certain size, while development can not be measured with a gauge.
B. Growth and Development in Plants
Developments in plant begins with fertilization. In early development, the embryo get food from the cotyledons. Cotyledons contained in the seeds of higher plants. Dikotil plants have two cotyledons, while monocots have one cotyledon. Early growth of seeds to plant a new crop called germination. Based on the kotiledonnya, germination can be divided into two kinds, namely epigeal and hipogeal. a. P there epigeal germination, cotyledons are at ground level motivated by hipokotil growth that extends upward.
b. In hipogeal germination, cotyledons remain underground, while plumula out of the ground surface caused epikotil growth that extends upward.
Growth in plants occurs in the meristem (growing point) contained in ujng roots and stems. Meristem will undergo mitotic division. Therefore, the end of the rod and the rod tip will grow long and large.
Growth caused by the huge and long cells themselves. In the trunk there are two types of shoots, the shoots are located at the end of the rod is called the terminal bud and contains the apical meristem, as well as the side shoots that will form a branch of the stem, leaves, and flowers.
Stem of the plant in addition to increased length also increased. This is due to the activity of cambium, which includes the meristem tissue cells actively divide. Location of cambium between the xylem and phloem tissues. Cambium tissue will continue to form new xylem and phloem that the longer rod would be great. Cambium activity leaves a clear limit on the stem. This limit is called the circle of the year.
C. Factors Affecting Growth and Development in Plants
Growth and development in plants is influenced by genetic factors and hormones, water and nutrients, light, oxygen, temperature, humidity, and pH.

    Genetic Factors
Genetic factors contained in the genes. The genes present in the chromosomes in the cell nucleus. These genes affect the size and shape of a plant. This is because the gene controls the synthesis of enzymes to control chemical processes in the cell. Chemical processes in the cell that causes the body's growth and development of plants.

    Hormones Factor
Hormones are organic compounds of plants that can cause physiological responses in plants. Hormones plant variety, but there are five essential plant hormones, namely:

    a. Auxin
Auxin is a hormone derived from the growing plants, such as the tip buds, cambium, flowers, fruit, and root tips. Auxin serves to stimulate stem cell growth tip, lateral root growth and root fibers and stimulate the formation of flowers and fruit. In addition, the activity of auxin function accelerates cell division and causing growing point differentiation into xylem cells.

    b. Cytokines
Cytokines are growing substance that was first discovered in the tobacco rod. This hormone has several functions, among others: 1) Stimulate differentiation of these cells produced in the meristem. 2) Delaying an abortion and aging of leaves.
3) Minimize the apical dominance that encourages the growth of side shoots and leaf expansion. 4) Stimulates cell division in meristematic tissue. 5) Stimulate the formation of shoots and capable of breaking
the break seed.

    c. Gibberellins
Gibberellins are growing substance that has properties like auxin. Gibberellins are found in almost all parts of the plant, such as seeds, young leaves, and roots. Gibberellins have several functions, among others: 1) Encourage the extension of the abnormal stem intact. 2) Influencing the development of flowers and fruit. 3) affects seed germination. 4) Stimulate cell division and elongation. For a dwarf plant, if given gibberellins will grow normally.

    d. Ethylene Gas
Ethylene gas produced by the fruit of old, but
still green and stored in a sealed bag to quickly cook. Ethylene gas also serves stimulate seed germination, stem thickening, encourage leaf drop, delay flowering, stem elongation and inhibit germination.

    e. Abscisic acid
Abscisic acid is a plant hormone that inhibits growth. This hormone is necessary plants when environmental conditions are not good. For example, during the dry season or winter, the plants shed their leaves to reduce excessive evaporation. This is done by regulating the opening and closing of stomata, especially in times of water shortage.

    Factors Water and Nutrition
Plants need water and nutrients for growth and development. These nutrients must be available in sufficient quantities and balanced. Plant nutrients taken from the soil and air.
The elements of the required plants grouped into two types, namely organic substances and inorganic. Organic substances, such as C, H, O, and N, whereas inorganic substances, such as Fe, Mg, K, and Ca. Plant growth will be disrupted if one of the required elements are not met. For example, the lack of nitrogen and phosphorus in the plant causes the plant becomes stunted. Magnesium and calcium deficiency causes plants had chlorotic (pale leaves).

    Factors Light
Light is necessary plants to carry out photosynthesis. This process produces the necessary nutrients for plant growth and to be kept as a reserve food that can be consumed by humans and animals.
Light effects enhance the action of the enzyme to produce metabolic substances for the formation of chlorophyll. Meanwhile, the process of photosynthesis, light intensity affect the rate of photosynthesis when the light reaction takes place.
D. Growth and Development in Animals
Animals also experience growth and development. Growth in animals is the result of the process of mitotic cells. This causes the cells to swell so that the animal's body to be big and long. Meanwhile, development is the differentiation of cells undergoing division into adult individuals. Growth in animals is often referred to as the development, namely the development of a zygote to adult. Growth begins with the fusion of an ovum (egg) by spermatozoa (sperm cells), and the resulting zygote. Zygote will bermitosis constantly.
The phases of development of the zygote through several stages, namely:

    a. Morula stage
In early development, the zygote divides into 2, then 4, 8, and so form a shape like mulberries called morula. Morula containing many mitotic cells results converge into a single unit.

    b. Blastula stage
From the morula to blastula. In this stage still ongoing process of cell division, forming a cavity in the center of the so-called blastosol.

    c. Gastrula stage
From blastula to gastrula. In this stage, the formation of the notches (blastopor) which has two layers. Subsequently, the cells lining the surface ectoderm undergo pelekukan into (invagination). These cells fill the space between the ectoderm and the endoderm forms the mesoderm layer.

    d. Organogenesis (organ formation)
At this stage occurs differentiation (development of cells to form specific structures and functions) from: 1) the ectoderm into the skin, nervous system, nose (sensory tools), anus, skin glands and mouth. 2) Mesoderm into bone, muscle, kidney, heart, blood vessels, and genitals. 3) endoderm becomes the glands have a relationship with the digestive tract, lungs, and digestive alatalat.
After organogenesis is complete, further refinement embryos into fetuses that are ready to be born (higher animals).
In vertebrates, there are two types of places embryonic development, which is outside the mother's body and in the body of the parent. The embryo grows outside its mother's body, for example in fish, reptiles, amphibians, and birds. Meanwhile, the embryo grows inside the mother's body, which is in the womb (uterus). The embryo in the uterus length depending on the type of animals.
In insects and amphibians, in its development into a mature animal having a different shape changes with the previous stage. It is called metamorphosis. This development occurred from eggs or larvae and will reach sexual maturity in adulthood.
Metamorphosis is divided into two kinds, perfect and imperfect metamorphosis. An example is the metamorphosis of butterflies and frogs. Meanwhile, incomplete metamorphosis occurs in locusts.
Metamorphosis in frogs through several phases, namely:
tadpole eggs → → → tailed frog adult frogs
Meanwhile, the metamorphosis of the locusts were: egg → larva → adult.
E. Human Growth and Development
Humans undergo two stages of growth and development, the prenatal and postnatal. The following is a description of the stages of prenatal and postnatal growth in humans.

    Growth PreNatal
The process of growth and development in humans since the beginning of fertilization (fertilization of an ovum by a sperm) that forms the zygote. Zygote continues to divide to form embryos. Here is a prenatal growth and development in humans.

    a. Fertilization (Conception)
In this process of fertilization occurs between the egg and sperm cells that produce the zygote, genetically be male or female. From one cell to grow into two cells, four cells, and so on. These cells will form the embryo's body and internal organs, external organs, yolk amnio, and chorion.

    b. Day-6 s.d 9
In this phase, the embryo will implant itself or attached to the mother's uterus.

    c. Week-2
Here the first growth occurs embryonic brain cells. Body formed embryo into 3 layers. The outer layer (eksoderm) will evolve into the outer layer of the skin and nervous system. The middle layer (mesoderm) will develop into blood vessels, bone, cartilage, and muscle. The inner layer (endoderm) will develop into the internal organs and glands.

    d. Week-3
Embryonic heart began to beat, originally only had one room. The organ is still experiencing growth and development until the whole can function fully. Brain and spine apart. The brain is divided into three segments, namely the forebrain, midbrain, and hindbrain. Placenta and limbs, such as arms and legs begin to form.

    e. Week-4
Circulation to and from the placenta begins. The placenta is an organ of the circulatory system between mother and embryo. Through the placenta, the mother gave nutriens and oxygen to the embryo. Growing the fingers on the hand, has legs, thighs, and tools organs begin to grow, such as the tongue, esophagus, and stomach. In addition, kidney, liver, gall bladder, and pancreas develops for several days. The lungs begin to develop, thyroid gland, and other forms. Face, sensory organs, and reproductive organs begin to form.

    f. Week-5
Parts of the brain have specialized functions. 40 days and brain waves can be detected. Have formed palate (the inner lining of the mouth with the tongue), complete with his teeth. The face is like the shape of a human face. In this week, the embryo starts moving. This initial movement is important for the healthy development of muscles.

    g. Week-6
Nervous system activity could be recorded. The embryo looks like a miniature baby and head look bigger because of the growth of the brain fast enough. The radius of the embryo is clear. His face and lips are sensitive to touch. Several organ systems, such as the heart and the nervous system (the brain) is ready to function. Toes obvious.

    h. Week-8
The embryo has become a fetus because it has completed the process of organogenesis (development and organ formation). Fetus genitals are sensitive to touch. Closing the eyes begin to form (eyelid).

    i. Week-10
Fetus has been able to maintain their position and the position sucking his thumb, making breathing movements and swallowing movements. The palms and soles of the feet fetus is sensitive to touch. The sense of smell begins to develop. Fetal movement is usually constant, it can move, kick, turn upside down, stretch, and move the arm.

    j. Week-11 s.d 13
Bone marrow started producing white blood cells. Reproductive organs outside looks. Week 11, the penis and the clitoris looks the same. The inside of the ear is formed, the possibility of the fetus can hear. Bones begin to experience the process of ossification, bone becomes hard as an adult, but the fetus still has a soft bone. Sense of taste develops.

    k. Week-14
Fetus reacts to sounds and no reaction when they hear that. Fetus can feel the emotion of happy and sad at the mother. Mother can feel the fetus kick is strong.

    l. Week-15 s.d 16
Fingerprints fetus has existed, has been coated nerve myelin, and the whole body of the fetus is sensitive to touch.

    m. Week-19
The baby is still young age. If born at this time, are susceptible to infection, the immune system (immune system) is not perfect, and there may be problems in breathing.

    n. Week-24
In this age, when the baby is born could likely survive outside the womb.

    o. Week-38
Usually babies born at this age. The baby's lungs have fully functioning immune system and are ready to face the outside world.

    Postnatal Growth
S nce the baby is born, the stages of human growth and development is the toddler and children, adolescence, adulthood, and old age (seniors).

    a. Period Toddlers and Children
Birth of a changing environment. Growth and development happens after birth is a process of continuation of the process of change of the embryo and fetus. Babies are breastfed (breast milk) for growth.
After the baby is born, the first adjustment is breathing because after the birth supplies O
mother interrupted. When the baby is born, the sudden changes between the warm air inside the womb with cool outside air causing the baby to cry so exciting air to enter the lungs and breathing began.
By the time the baby is born, the baby teeth and incisors have been there in the gums. However, baby teeth usually grow at the age of six months or seven months. Lower teeth grow ahead of the upper teeth. First molars appear between the ages of 12 and 16 months, then the canines follow.
At 1 month of age, babies begin to turn their heads, learn to focus the eyes, as well as coordinating with de eyes follow moving objects. 2 months of age began to smile. Furthermore, coordinating baby hands to hold objects.
3 months of age, babies begin to learn to speak. 6 months old baby has started to differentiate between people who knew and strangers. Entering the age of 7 months, babies begin to spin, sit, then crawl, learning to stand while holding onto. Furthermore, standing without holding at the end of the first year. In addition, start learning to imitate an assortment of sounds that have specific meanings.
The second year, already knowing his relationship with the family, and wanted to know everything. Dah your attention diverted. Between the ages of 1-3 years, babies learn to focus and interest in objects, learn not to depend on others. Feelings of anxiety and fear starts there. Learn faster, can run, start babbling to talking, investigating the house and its surroundings, and learn to feed themselves.
Between the ages of 3-6 years, the nature of curiosity is very prominent. Many ask, the ability to grow with regular observations that begin to solve simple puzzles. Chimera kid growing rapidly, full of imagination, such as friends playing pretend, imaginary father, and imitating their parents.

    b. Adolescence and Puberty Period
By the age of 6-11 years, the early growth of the body occur quickly, then slow down. Children begin not depend parents, began to develop sense of self-control. Forming groups and collection of its own. Starting interested in good behavior, and regular. Intelligence and understanding grow, realize the importance of learning, began to develop new ways of reading and learning.
In adolescence there is a change in the physical growth that includes personal growth and maturity. This period is the human stage to adulthood is often referred to as puberty.
During puberty, the body growth occurs very rapidly, this period is a period of maturation, both in men and women. At puberty these men and women have been able to produce sperm and the ovum (egg) is characterized by secondary sex characteristics.
Puberty in women usually occurs at the age of 9-13 years. Women will increase in height and body fat to lean quickly.
Secondary sexual traits in women that can be seen, such as enlarged breasts, enlarged pelvis, hair grows around the genitals and armpits, sometimes acne. In addition, the maturity of the reproductive organs is characterized by getting your period (menstruation) first. This marks the first release of the ovum from the ovary. Height increase slowed.
Puberty occurs in men between the ages of 10-14 years. During this maturation is characterized by the formation of reproductive organs and sperm occurs sperm expenditure during sleep (wet dreams).
Secondary sex traits in males, such as growing hair around the genitals, armpits, grow a mustache, beard, grow Adam's apple, a big voice, bigger muscles, and chest into the field. After age 14 years, height increment will be reduced or slowed down. At puberty rapidly evolving intelligence, speed and accuracy of motor skills stand out, and mental development are formed.

    c. Adulthood
In adulthood, the human height growth stops. Psychologically, people have matured in mind waking up to its responsibilities. Thinking about the importance of work and education for the future, as well as plans for a family.

    d. Seniors
Humans are not forever be in peak power. Growing old is a process commonly experienced by all living things, including humans. Elderly man often called manula.Pada the elderly, the growing strength of the bone is reduced. If the injury is hard to recover. The state of reduced metabolic balance, wound healing decelerates, employment decreased body organs, reduced skin elasticity and graying hair.
In women (aged 48-50) experiencing menopause, the end of the reproductive ability of producing ova. In men the possibility of decreased sexual ability.
An orderly decline in terms of smell, hearing, sight, and memory. In the elderly are common health problems. It depends on the humans, how to nurture and maintain good health. During this period, human responsibility is usually reduced.