Chapter-12 Reproduction in Plants

Explanation:

The flower contains the reproductive structures of the plant, including the male parts (stamen), which produce pollen, and the female parts (pistil), which contain the ovary, where the eggs are produced. Once the pollen from the flower's male parts is transferred to the female parts, fertilization can occur, and the plant can produce seeds.

Explanation:

The zygote is formed when the sperm cell from the male gamete fuses with the egg cell from the female gamete during fertilization. The zygote is the first cell of the new individual that will develop into a mature organism through a series of cell divisions and differentiation.

Explanation:

Stamen is considered the male reproductive part of the flower. The stamen comprises two main parts: the anther and the filament. The anther is the top part of the stamen, producing and releasing pollen. The filament is the long, slender stalk that supports the anther and positions it for optimal pollen dispersal. The stamen is responsible for producing and delivering male gametes (sperm cells) to the female reproductive parts of the flower, where fertilization can occur.

Explanation:

Pistil is known as the female reproductive part of a flower. The pistil is located at the center of the flower and consists of three main parts: the stigma, the style, and the ovary. After pollen is deposited on the stigma, it travels down the path to the ovary, where fertilization can occur, and the ovules can develop into seeds. The pistil is responsible for producing and protecting the female gametes and facilitating flower fertilization.

Explanation:

After fertilization, the mature ovary of a flower develops into a fruit. The fruit is the ripened ovary of the flower that contains seeds. As the ovules inside the ovary are fertilized and begin to develop into seeds, the ovary grows and changes its structure, becoming the fruit we eat.

Explanation:

Nodes are essential because they are the points where plant growth occurs, and they determine the spacing and arrangement of leaves and branches along the stem. The distance between nodes can vary depending on the plant species and its growth pattern, and it can be influenced by factors such as light, water, and nutrient availability.

Explanation:

Ferns are a large group of plants that reproduce by spores. The spores are produced on the underside of the fronds and are released into the air when they mature. Mosses are small, non-vascular plants that reproduce by spores. The spores are produced in a capsule at the stalk's tip and are dispersed by the wind.

Explanation:

The spores of Rhizopus can be found in the air, and when they land on a suitable food source like bread, they begin to grow. The fungus grows as a network of branching filaments called hyphae. These hyphae secrete enzymes that break down the complex molecules in the bread into simpler molecules that the fungus can absorb as nutrients.

Explanation:

Reproduction in plants are of two types - Sexual reproduction and Asexual reproduction. 

Sexual reproduction involves the production of male and female gametes (sex cells) that combine to form a zygote, which develops into a new individual plant.

Asexual reproduction can occur through various means, including vegetative propagation, fragmentation, and apomixis. In vegetative propagation, a new plant is produced from a part of the parent plant, such as a stem or leaf.

Explanation:

Fertilization is the process by which male and female gametes unite to form a new individual with a unique combination of genetic traits. In plants, fertilization typically involves the fusion of a pollen grain containing male gametes with an egg cell located in the female reproductive structure of the plant, such as the ovule in the flower.

Explanation:

Reproduction is the biological process by which living organisms produce offspring of the same species. Reproduction is essential for the continuation of a species and the survival of the organisms that make up that species.

Explanation:

Many plants can grow from roots in various ways, either through adventitious rooting, root tubers, or root cuttings. New plants can grow from the roots of some plants and can have various utilities. Potatoes and dahlia are a few examples of such plants. 

Explanation:

Sexual reproduction in cacti involves the production of flowers, which can be large and showy or small and inconspicuous, depending on the species. The flowers open at night and are pollinated by nocturnal animals such as bats, moths, or bees. The pollinated flowers then develop into fruits containing seeds. 

Explanation:

Pollination is the transfer of pollen from the male reproductive structure (anther) to the female reproductive structure (stigma) of a flower or plant, leading to fertilization and seed production. It is of two kinds -

•  In self-pollination, the pollen from the anther of a flower is transferred directly to the stigma of the same flower or another flower on the same plant.

•  In cross-pollination, the pollen from the anther of a flower is transferred to the stigma of a flower on a different plant of the same species. 

Explanation:

Unisexual flowers have either male or female reproductive structures, but not both. These are also called "imperfect" flowers, as they lack the complete set of reproductive organs found in "perfect" flowers.

Explanation:

Bisexual flowers have both male and female reproductive structures, including the stamen (male) and the pistil (female) parts. These are also called "perfect" flowers, as they have both reproductive organs.

Explanation:

Binary fission, budding, vegetative reproduction, and fragmentation are different kinds of asexual reproduction.

Binary fission is a standard mode of asexual reproduction in bacteria, where the parent cell divides into two daughter cells of equal size. In budding, a new organism develops as an outgrowth or bud on the parent organism. Fragmentation occurs when the parent organism breaks apart into two or more fragments, each of which can regenerate into a new individual. Vegetative propagation is a mode of reproduction in plants where a new plant develops from a part of the parent plant, such as a stem, root, or leaf.

Explanation:

The vegetative parts of a plant are the parts that are involved in the growth, development, and maintenance of the plant and do not play a direct role in reproduction. Roots, stems, and leaves perform such roles in a plant.

Explanation:

During sexual reproduction, the sperm and egg cells unite during fertilization to form a zygote, the new organism's first cell. The zygote contains a combination of genetic material from both parents and undergoes multiple rounds of cell division to form an embryo. As the embryo develops, it eventually forms a complete organism that inherits a unique set of traits from each parent.

Explanation:

In asexual reproduction, a single organism produces genetically identical offspring without the involvement of gametes or the fusion of genetic material from two different individuals. On the other hand, in sexual reproduction, two different organisms contribute genetic material to produce genetically unique offspring. This occurs through the production of specialized cells called gametes (sperm and egg cells), which combine during fertilization to form a zygote. 

Explanation:

It would result in a dense cluster of plants that are competing for the same resources, including sunlight, water, and nutrients. This is known as overcrowding, and it can negatively affect plants. For example, as the plants grow and their leaves and branches become denser, they may start to shade each other, reducing the amount of light each plant receives. 

Explanation:

The function of flowers in plants is to facilitate sexual reproduction by producing male and female reproductive structures and attracting pollinators that aid in the transfer of pollen between flowers.

Explanation:

Seed dispersal helps to reduce competition among plants by allowing the seeds to germinate and grow in new areas where there may be less competition for resources such as sunlight, water, and nutrients. Seed dispersal helps to promote genetic diversity by allowing seeds to be dispersed over a wide area. 

Explanation:

Berries are fleshy fruits that contain seeds. They are often eaten by animals like birds, bears, and rodents, which then disperse the seeds in their droppings. Pods are fruits that split open to reveal seeds. Examples include legumes like peas and beans, which animals often eat, like deer and rabbits.

Explanation:

Potatoes reproduce asexually through a process called vegetative reproduction. Instead of producing seeds like most plants, potatoes develop structures called tubers, which are enlarged, underground stems that contain the plant's nutrients and energy reserves.

Explanation:

Reproduction in plants takes place in two forms that are sexual reproduction and asexual reproduction.

Sexual reproduction involves the fusion of male and female gametes (reproductive cells) to create a new organism with a combination of genetic material from both parents. This process usually involves pollination, where the male reproductive organ (anther) pollen is transferred to the female reproductive organ (stigma) of the same species. Asexual reproduction, on the other hand, does not involve the fusion of gametes and produces offspring genetically identical to the parent plant.

Explanation:

Pollination occurs when pollen from the male reproductive structure, the anther, is transferred to the female reproductive structure, the stigma, of the same or a different flower. Once the pollen reaches the stigma, a pollen tube grows down through the style to the ovary, where it reaches the ovule. The nucleus of the sperm cell in the pollen fuses with the nucleus of the egg cell inside the ovule, forming a zygote. This zygote then develops into seeds which later help in germination for the new plant growth.

Explanation:

Self-pollination occurs when the pollen from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant. Cross-pollination, on the other hand, occurs when the pollen from the anther of a flower on one plant is transferred to the stigma of a flower on a different plant of the same species.

Explanation:

Stem cutting is the most popular method of propagating roses. Take a stem cutting from the parent plant about 6-8 inches long and has at least 2-3 leaves. Remove the lower leaves and dip the cut end of the stem into rooting hormone powder. Another method is grafting, which is a method of propagation that involves combining the stem of the parent plant with a stem from another rose plant.

Explanation:

Fruits and seeds are made from sexual reproduction in plants. 

Pollination occurs when the pollen from the anther of the male reproductive organ is transferred to the stigma of the female reproductive organ. After pollination, the zygote gets formed, which is later converted into seeds. Moreover, the matured ovary turns into fruit.

Explanation:

Algae reproduce asexually, meaning that they produce offspring without the involvement of another individual. This can happen through various means, such as cell division, fragmentation, or spore formation. For example, some green algae can produce spores that develop into new individuals without fertilization.

Explanation:

Vegetative propagation is a method of asexual reproduction in plants in which new plants are produced from vegetative parts of the parent plant, such as roots, stems, or leaves. This method does not involve the formation of seeds or the fusion of gametes. Therefore, the new plants are genetically identical to the parent plant, a process called cloning.

Explanation:

Yeast reproduces asexually through budding and sexually through the fusion of haploid cells of opposite mating types. Both methods of reproduction ensure genetic diversity and adaptation to changing environmental conditions.

Explanation:

Mosses and ferns reproduce through a complex process of alternation of generations, which involves the production of gametes by the gametophyte, the fertilization of the egg by the sperm, and the production of spores by the sporophyte. This method of reproduction ensures genetic diversity and adaptation to changing environmental conditions.

Explanation:

Fertilization in flowers involves the transfer of pollen from the anther to the stigma, the growth of a pollen tube down through the style to the ovary, and the fusion of male and female gametes to form a zygote and endosperm. This process leads to the development of seeds, which are essential for plant reproduction and survival.

Explanation:

It happens through the growth of a pollen tube, which penetrates the ovule and releases the male gametes for double fertilization. This process is crucial for developing seeds, which are essential for plant reproduction and survival.

Explanation:

Some seeds are lightweight and have wing-like structures or hairs that enable them to be carried by the wind. Seeds that can float or survive in wet environments are dispersed by water. Some seeds have hooks, spines, or other adaptations that allow them to attach to animal fur or clothing and be carried to new locations.

Explanation:

Reproduction through spore formation is a standard reproduction method in fungi. Spores are reproductive structures produced by fungi and used for the dispersal, germination, and growth of new individuals.

Explanation:

Different kinds of asexual reproduction are- 

• Binary fission: This method involves splitting a single-celled organism into two identical daughter cells. 

• Budding: This method involves the growth of a new individual from a small outgrowth on the parent organism. 

• Fragmentation: This method involves breaking off a part of the parent organism, which then grows into a new individual. 

• Regeneration: This method involves regressing a lost body part, which then develops into a new individual.

Explanation:

Regeneration in plants refers to the ability of specific plant tissues to develop into new plants. Regeneration is an essential aspect of plant biology and has practical applications in horticulture, agriculture, and biotechnology.