* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Erica-Mae N. Alim ABM-106 PERPETUATION OF LIFE Summary
Survey
Document related concepts
Gartons Agricultural Plant Breeders wikipedia , lookup
Plant secondary metabolism wikipedia , lookup
Plant use of endophytic fungi in defense wikipedia , lookup
Plant defense against herbivory wikipedia , lookup
History of botany wikipedia , lookup
Evolutionary history of plants wikipedia , lookup
Plant breeding wikipedia , lookup
Plant physiology wikipedia , lookup
Plant morphology wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
Plant ecology wikipedia , lookup
Perovskia atriplicifolia wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Fertilisation wikipedia , lookup
Flowering plant wikipedia , lookup
Transcript
Erica-Mae N. Alim ABM-106 PERPETUATION OF LIFE Summary. Earth is inhabited by a wide variety of living things from smallest bacteria to the biggest animals. plants are said to be one of the earliest inhabitants on earth. fossils imprints of some ancient ferns serve as evidence of the existence of plants during prehistoric times. the survival of the present day organisms rely on their abilities to survive and reproduce. organisms perpetuate through reproduction and each organism is part of a reproductive continuum that goes back countless generations. the plant reproduction is the process of generating new plant individuals or offspring. plants reproduce in two ways: the sexual reproduction and the asexual reproduction. Sexual reproduction in plants involves the fussion of the parents gametes, which give rise to an individual that has the genes of both parents. thus, the offspring is not genetically identical with either or both of the parents. instead, it carries combined genes. sexual reproduction in plants starts with pollination. pollination is the transfer of pollen from the anther to the stigma of the flower. the pollen grains absorbs moisture in the stigma and sprouts, producing a pollen tubes that burrows deep into the style of the pistil until it reaches the ovary. the two male gametes travel down the pollen tube into the ovary. once inside the ovary, the two sperm nuclei enter the ovule. one sperm fertilizes the egg and becomes the embryo, a diploid (2n). the other sperm fertilizes the two polar bodies and becomes the endosperm, a triploid (3n). the endosperm is a nutrient-rich tissue which serves as nourishments for the growing embryo. this process is called double fertilization. after fertilization, the ovule becomes the seed and the matured or ripened ovary becomes the fruit. The Asexual reproduction is a type of reproduction that creates genetically identical offsprings. the offspring that arise from asexual reproduction can be considered clones. in most plants, asexual reproduction is an advantageous adaptation. asexual reproduction in plants usually arises from the vegetative parts (stem, roots, and leaves) of the plant. this is also called vegetative reproduction. some plants gives rise to new plant using their modified or specialized stems, such as stolons, tubers, bulbs and corms. stolons or runners are specialized stems of some plants such as the strawberry. rhizomes are stems which grow horizontally under the ground. tubers, are used both for starch storage and give rise to new plants. an example is potato plants. bulbs are underground stems that gives rise to a new plant, such as in the case of onions and lilies. corms differs from the bulb since it is also used for storage of food of the plant, sometimes reffered to as the bulbotuber. corms give rise to new small corms in their nodes called cormels. some plants such as the bryophyllum reproduce asexually on their leaves. new plants arise from their specialized leaves that can later on be planted on the ground and become new individuals. A flower consists of highly specialized male and female reproductive organs. the female reproductive part of the flower or pistil has stigma, style, and ovary. the ovary contains the ovule that has the egg nuclei. the stamen on the other hands, is the male part of the flower. it has the anther that produces pollen grains, which contain the sperms. The seed usually consists of a seed coat, embryo, and endosperm. The seed coat protects the internal parts of the seed againts external factors. it also helps in the dormancy of the seed. The endosperm serves as the food for the growing embryo. eudicot seeds such as beans, nango and jackfruit have two cotyledons, while monocots like the corn, wheat and rise have one cotyledon. The embryo has three parts: hypocotyl, epicotyl, and radicle. The hypocotyl becomes the lower part of the stem. the radicle or the embryonic roots become the primary root and the first organ to emerge in plants. The epicotyl becomes the upper part of the stem and gives rise to the shoot. after the seeds are formed and become matured,they are usually scattered in the environment where they can grow as new plant.this scattering of seeds is known as seed dispersal.this process is very important in the survival and distribution of the plants speciea. there are different ways by which seeds are dispersed.external factors such as wind,animals,humans,and water help in the succesful dispersal of seeds.some seeds such as dandelion and mahogany have specialized structures intended for easy dispersal.some have thorns or sticky surface that can cling on to sone animals.most human and animals eat fruits.they throw the seeds on the ground where they become new plants.germination is the early growth stage of a plant embryo.germination leads to maturity,which leads to reproduction. Reproduction in animals, like plants, animals also reproduce. by reproducing, an animal can be sure that there is another individual of its kind that can take its place on earth when it dies. During sexual reproduction in animals, a haploid sperm cell and a haploid egg cell unite to form a diploid zygote. the process wherein a sperm and egg unite is called fertilization. the zygotes divides and differentiates into an embryo. The embryo then grows and develos until the time of birth or hatching. most animals exhibits cross-fertilization, meaning, fertilization involves two separate individuals of the same species (a male and female) in reproduction. even earthworms which has two sexes (hermaphrodite), do cross-fertilization. in the event that mating of two individuals is not possible, for instance, when no other organisms is in the vicinity or the union of egg and sperm is not possible, some species of animals undergo self-fertilization like that of the tapeworms in the intestine. frogs, crabs, coral and most fishes undergo external fertilization. that is, meeting of gametes does not happen inside the body of the female animal, but in the open environment or outside the body. notice that most of them are aquatic animals, while others can stay in water (in case of some amphibians). their aquatic or wet environment makes it possible for the sperm and egg to meet for the fertilization process. these animals release large number of eggs and sperm to increase the rate of successful fertilization. environmental factors such as predators, drying up of the environment, abd flactuating temperatures may hinder the fertiluzation of some gametes. after a successful fertilization, the zygote grows and develops. most vertebrates, such as birds, fish, and most amphibians and reptiles, lay eggs. the egg is surrounded and protected by a tough membrane or shells. Human Reproduction,most fertilization happens inside the body of the female species,wherein the male deposits the sperm in the female's reproductive organ during mating.this is called internal fertilization.internal firtilization is said to be one adaptation of land animals which led to succesful reproduction of species .the growth and development of the offspring happen in the uterus of the mother.while inside the mother,the mother embryo is nourished through the umbilical cord. Asexual reproduction in animals, some animals are also capable of asexual reproduction, which usually occurs when sexual reproduction is not possible. asexual reproduction in animals occurs in invertebrates and can be done through budding or fragmentation. Budding involves the splitting of new individuals from an existing organisms by forming small projections, called buds, from the parents body. Fragmentation and regeneration is a type of asexual reproduction wherein a single parent breaks into parts that give rise to new individuals. sponges, planaria, and starfish are examples of animals that exhibit this type of asexual reproduction. Parthenogenesis is a form of asexual reproduction in some animals that give rise to the growth and development of an embryo without fertilization. One role of reproduction is the transfer of hereditary materials from the parents of their offsprings. genes are the molecular unit of heredity of all organisms. organisms that reoroduce through asexual reproduction tend to grow in large numbers but have a disadvantage when it comes to species vulnerabilities. asexually reproduced offspring tend to have very similar characteristics from its parents. hence, they inherit even its way of adaptation. gene variation only happens in simple mutation. one parent alone passes on a duplicate of all its genes to the newly-produced individual. Reaction. I learned how the plants, animals and other organisms started to live and build their own family. i also learned the process on how they grow using their own organ. In this chapter i learned and know what the value of all the things that sorround us and also what we should do and should not we do. because, if we do not determine the value and worth of each organism it can cause harmful accident to all of us. many of us have the possibility to suffer any kind of disease and illness. so that, in this chapter we should always remember that we must need to avoid destroying plants or even kill any organisms around us, because, like us, they also have the potentials to live and reproduce. all the lesson i got in this chapter., i use it in my everyday life and also i would share it with my brothers and friends.