Diploid tissue differentiates to produce specialized sporangiu
Meiosis gives rise to diploid saprophyte stages. Stage three: sporangia - preserved spores. Effective spore dispersal on land. Step Four: Develop a Large Sporophyte. Height confers a competitive advantage. Perennial spore production. Step Five: Remove dependence on water for reproduction. Enables it to survive in dry environments. Evolution of Plant Life Cycle: (1) Primitive plants evolved from a green algal ancestor with a zygotic (haploid) life cycle.
In such organisms, the zygote undergoes meiosis to produce haploid spores. The zygote is the only diploid cell in this type of life cycle. (2) How did the sporophyte, or diploid stage, of the life cycle evolve in primitive plants? Most botanists believe that the sporophyte evolved as a result of a delay in meiosis in the zygote.
Instead of meiosis, the zygote divides by mitosis, leading to the development of a multicellular diploid stage, the sporophyte. (1) Step One: Become Multicellular. occurred in water ("algae stage"). allowed to develop specialized tissues. (2) Stage two : Heterogeneous life cycle. Protective chamber (ogonium) for eggs.
The diploid tissue then began to differentiate to produce specialized sporangium that was overladen to the maternal gametophyte. The cells that undergo meiosis are confined to the sporangium. This ensures that the haploid spores (products of meiosis) can be released from the sporangium and dispersed away from the parent by wind.
The spores eventually germinate to produce a new haploid gametophyte. Gametes are formed from the gametophyte and the cycle continues. Successive stages in plant development: Developing a larger sporophyte: Early plants had a free-living, gametophyte-like thallus and dependent, single-stemmed sporophyte that remain attached to the parent gametophyte.
The development and diversification of plants involved the development of a large independent sporophyte. There were two major advantages to developing a large sporophyte: (1) the ability to differentiate and (2) the ability to produce multiple sporangia. It is seen in ferns and other primitive vascular plants.
The sporophyte in ferns is dependent on the gametophyte when it is in its primitive state. The sporophyte basically grows from a gametophyte and then develops roots, rhizome and compound leaves. Large size enables effective spore dispersal along with competition. Enables perennial root stock.
Study of individuals in the early stages of adolescence
Child Psychology Concept and Form Introduction to Education Psychology has been interested in the human child since ancient times. The child has always been at the center of the family. The arrival of a child in the family is a thrilling and enjoyable experience for all. The child is the sacrificer of the Lord.
“The child is a citizen of tomorrow. The importance of the child has been accepted by our society by saying, "The child is the father of man." Sociologists and ethnographers have made significant contributions to the development of child psychology. Elizabeth Harlock "Child psychology is the study of the human. Development from conception to adolescence.
"Elizabeth Harlow" Child psychology A study of human development from ovulation to puberty. Tea. Jersid' Child psychology is the science that studies individuals from the prenatal stage to the early stages of adolescence.
"Understanding, Predicting, and Controlling Behavior. - John E. Anderson Psychology seeks to understand a child's behavior, make predictions about it and tries to turn it in the right direction.
Child psychology in educational psychology Child psychology child psychology is an independent branch of psychology. Child psychology is a biological social science. Child psychology is a natural science. Child psychology is a theoretical and applied science.
The above forms of child psychology are discussed in detail below: Child psychology is an independent branch of psychology. Psychology studies human behavior. Childhood is one of the most important stages in the life of a human being. This stage has some special features. Hence it needs to be studied independently and in detail. Whereas the principles of psychology were applied to explain child behaviour.
0 Comments