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Spores
Some protozoans and many bacteria, Plants and Fungi reproduce via spores. Spores are structures naturally grown as part of an organism's life cycle and designed for separation from the organism and dispersal via a medium such as air or water. When conditions are correct, the organism will release its spores, which are each then considered entirely separate and autonomous organisms. Given an Environment suitable for life, the spores will then develop into fully grown organisms and eventually grow their own spores, repeating the cycle.
Fission
Prokaryotes and some protozoa reproduce via binary fission. Fission occurs at the cellular level when a cell's contents are replicated internally and then subjected to division. The cell then forms into two distinct entities and separates itself. Each partial cell then reconstitutes the missing parts of its internal structure. At the end of the process, the single cell has become two new fully developed cells, each with identical genetic properties.
Vegetative Reproduction
Many plants have evolved specialized genetic features that allow them to reproduce without the aid of seeds or spores. Examples include the prostrate aerial stems of strawberries, the bulbs of tulips, the tubers of potatoes, the shoots of dandelions, and the keikis of orchids. This form of specialization is most common in environments with seasonally harsh conditions; it allows plants to survive and thrive in situations where the traditional seeding process is subject to frequent interruption.
Budding
Organisms like proteins, yeast, and some viruses reproduce via budding, a process by which an entirely new organism grows on an existing one. Unlike fission, this is not brought about by the separation of an existing organism into two partial entities. The developing organism begins its life as an entirely separate life form from its "parent", separating into an autonomous entity only when it has fully matured. As the "child" organism proceeds through life, it will produce its own buds.
Fragmentation
Segmented worms and many echinoderms such as starfish reproduce asexually via fragmentation. In this process, an organism physically splits and develops new, genetically identical organisms out of each segment. The segments rapidly grow new cells to constitute their muscle fiber and internal structure through mitosis. This split can be either intentional or unintentional on the part of the organism.
Parthenogenesis
Parthenogenesis, a reproductive strategy that involves development of a female (rarely a male) gamete (sex cell) without fertilization. It occurs commonly among lower plants and invertebrate animals (particularly rotifers, aphids, ants, wasps, and bees) and rarely among higher vertebrates. An egg produced parthenogenetically may be either haploid (i.e., with one set of dissimilar Chromosomes) or diploid (i.e., with a paired set of chromosomes). Parthenogenic species may be obligate (that is, incapable of sexual reproduction) or facultative (that is, capable of switching between parthenogenesis and sexual reproduction depending upon environmental conditions). The term parthenogenesis is taken from the Greek words parthos, meaning “virgin,” and genesis, meaning “origin.” More than 2,000 species are thought to reproduce parthenogenically.
Grafting
Grafting is the process of joining two plants together (an upper portion and a lower portion) to grow as one. The upper portion of the plant is known as the scion, which is attached to the lower portion known as the rootstock. This is most often done for fruit trees, and virtually all trees in orchards are grafted. Grafting in the orchard is done because the seeds of a fruit tree cannot reproduce true to their genetics. Therefore, the branch of a desirable tree is grafted to a suitable rootstock.
Layering
Layering is a means of plant propagation in which a portion of an above-ground stem grows roots while still attached to the parent plant and then detaches as an independent plant. Layering has evolved as a common means of vegetative propagation of numerous species in natural environments. Layering is also utilized by horticulturists to propagate desirable plants.
sexual reproduction in plants
Reproduction in plants takes place sexually and asexually as well. But the majority of the flowering plants reproduce sexually. The flower is the reproductive part of a plant i.e., both male and female gametes are produced by flowers. Sexual reproduction in plants takes place in flowers. The complete flower typically consists of four parts:
- Petals
- Sepals
- Stamen (male reproductive part)
- Pistil/Carpel (female reproductive part)
Stamen (male reproductive part) consists of anther and filament.
- The anther is a sac-like structure that produces and stores pollen.
- The filament supports the anther.
Pollination & Fertilization
In order to form a zygote, male gametes in pollen grains have to fuse with egg in the ovule. This is achieved by the process called pollination. Pollination is the process of transferring pollen grains from the anther – male part of a flower, to the stigma – female part of a flower. Depending on the pollen landing, pollination can be classified into two types-
Self-Pollination: A pollination where the pollen transfer takes place between the anther and stigma of the same flower.
Cross-Pollination: A pollination where the pollen transfer takes place between the anther and the stigma of different flowers of the same plant or different plants of the same species.
Generally, pollination takes place with the help certain agents so called pollinators. They include insects, water, birds, the wind, etc. Once pollen gets transferred to stigma the male gametes from pollen grains release and fuses with egg in the ovule to form a zygote. This process of fusion of gametes is called fertilization. The zygote thus formed, divides and develops into an embryo, and later into a seed. The ovary develops into a fruit.
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Asexual reproduction is a type of reproduction that does not involve the fusion of gametes. This means that offspring are produced from a single parent and are genetically identical to the parent. There are many different types of asexual reproduction, including binary fission, budding, fragmentation, sporulation, vegetative propagation, and parthenogenesis.
Binary fission is a type of asexual reproduction in which a single cell divides into two identical daughter cells. This is the most common type of asexual reproduction and is used by many unicellular organisms, such as bacteria and archaea. Binary fission is a relatively simple process that begins with the replication of the cell’s DNA. The DNA is then divided equally between the two daughter cells, which then separate from each other.
Budding is a type of asexual reproduction in which a new individual grows out of a parent individual. This type of reproduction is common in yeast and some other fungi. Budding begins with the formation of a bud, which is a small protrusion from the parent individual. The bud grows and develops into a new individual, which eventually separates from the parent individual.
Fragmentation is a type of asexual reproduction in which a parent individual breaks into two or more pieces. Each piece can then grow into a new individual. This type of reproduction is common in some algae and sponges. Fragmentation can occur naturally, such as when an organism is torn apart by an animal, or it can be done artificially, such as when a gardener divides a plant.
Sporulation is a type of asexual reproduction in which an organism produces spores. Spores are small, typically single-celled reproductive units that can survive in harsh conditions. When conditions are favorable, spores can germinate and grow into new individuals. Sporulation is common in fungi, plants, and some algae.
Vegetative propagation is a type of asexual reproduction in which new individuals are produced from plant parts, such as roots, stems, or leaves. This type of reproduction is common in many plants, such as strawberries and potatoes. Vegetative propagation can occur naturally, such as when a plant root breaks off and grows into a new plant, or it can be done artificially, such as when a gardener takes a cutting from a plant.
Parthenogenesis is a type of asexual reproduction in which an egg develops into a new individual without being fertilized by a sperm. This type of reproduction is common in some insects, such as aphids and bees. Parthenogenesis can also occur in some vertebrates, such as fish and reptiles.
Asexual reproduction is a common and important form of reproduction in many different types of organisms. It is a simple and efficient way to produce new individuals, and it can be used to quickly colonize new areas. Asexual reproduction is also important for survival in harsh environments, as it allows organisms to produce new individuals even when there are no mates available.
Fission
- What is fission? Fission is a type of asexual reproduction in which a single cell divides into two or more identical daughter cells.
- How does fission occur? Fission begins with the replication of the cell’s DNA. The replicated DNA is then distributed to the two daughter cells. The daughter cells then divide into two new cells.
- What are some examples of organisms that reproduce by fission? Bacteria, archaea, and some protists reproduce by fission.
Budding
- What is budding? Budding is a type of asexual reproduction in which a new individual develops from a small outgrowth on the parent organism.
- How does budding occur? Budding begins with the formation of a bud, which is a small outgrowth on the parent organism. The bud grows and develops into a new individual. The new individual then separates from the parent organism and begins to live on its own.
- What are some examples of organisms that reproduce by budding? Yeasts, hydras, and some algae reproduce by budding.
Fragmentation
- What is fragmentation? Fragmentation is a type of asexual reproduction in which an organism breaks into two or more pieces. Each piece can then grow into a new individual.
- How does fragmentation occur? Fragmentation can occur naturally, such as when a plant is broken by a storm, or it can be done artificially, such as when a piece of a plant is cut off and planted.
- What are some examples of organisms that reproduce by fragmentation? Some algae, sponges, and sea stars reproduce by fragmentation.
Parthenogenesis
- What is parthenogenesis? Parthenogenesis is a type of asexual reproduction in which an egg develops into a new individual without being fertilized by a sperm.
- How does parthenogenesis occur? Parthenogenesis can occur naturally, such as in some insects and reptiles, or it can be induced artificially, such as in some mammals.
- What are some examples of organisms that reproduce by parthenogenesis? Some insects, reptiles, fish, amphibians, and birds reproduce by parthenogenesis.
Vegetative reproduction
- What is vegetative reproduction? Vegetative reproduction is a type of asexual reproduction in which new individuals are produced from plant parts other than seeds.
- How does vegetative reproduction occur? Vegetative reproduction can occur naturally, such as when a plant stem falls off and takes root, or it can be done artificially, such as when a gardener takes a cutting from a plant and roots it.
- What are some examples of organisms that reproduce by vegetative reproduction? Many plants, such as potatoes, strawberries, and bamboo, reproduce by vegetative reproduction.
Question 1
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes. It is a common form of reproduction in plants, animals, and fungi.
Which of the following is not a type of asexual reproduction?
(A) Budding
(B) Fragmentation
(C) Sporulation
(D) Sexual reproduction
Answer
(D)
Question 2
Budding is a type of asexual reproduction in which a new individual grows from a small outgrowth on the body of the parent organism. The new individual eventually separates from the parent and becomes a new organism.
Which of the following organisms reproduces by budding?
(A) Yeast
(B) Hydra
(C) Planaria
(D) All of the above
Answer
(D)
Question 3
Fragmentation is a type of asexual reproduction in which an organism breaks into pieces, and each piece grows into a new individual.
Which of the following organisms reproduces by fragmentation?
(A) Planaria
(B) Starfish
(C) Sea urchin
(D) All of the above
Answer
(D)
Question 4
Sporulation is a type of asexual reproduction in which an organism produces spores. Spores are small, asexual reproductive units that can survive in harsh conditions. When conditions are favorable, spores germinate and grow into new individuals.
Which of the following organisms reproduces by sporulation?
(A) Mosses
(B) Ferns
(C) Mushrooms
(D) All of the above
Answer
(D)
Question 5
Asexual reproduction is a common form of reproduction in plants, animals, and fungi. It is a simple and efficient way to produce new individuals. Asexual reproduction does not require the fusion of gametes, so it can occur even in the absence of a mate. This makes asexual reproduction a good option for organisms that live in isolated environments or that have a short lifespan.
What are some of the advantages of asexual reproduction?
(A) It is a simple and efficient way to produce new individuals.
(B) It does not require the fusion of gametes, so it can occur even in the absence of a mate.
(C) It is a good option for organisms that live in isolated environments or that have a short lifespan.
Answer
(A), (B), and (C)
Question 6
What are some of the disadvantages of asexual reproduction?
(A) Genetic diversity is reduced.
(B) Offspring are identical to the parent.
(C) The Population may become too large and outcompete other species.
Answer
(A), (B), and (C)
Question 7
In conclusion, asexual reproduction is a common form of reproduction in plants, animals, and fungi. It is a simple and efficient way to produce new individuals. However, asexual reproduction also has some disadvantages, such as reduced genetic diversity and the potential for overpopulation.