The miracle of life unfolds in Chapter 14 – Reproduction. In this chapter, we delve into the awe-inspiring processes that drive the continuity of life itself. Reproduction is the cornerstone of existence, enabling the transmission of genetic information from one generation to the next. From the tiniest microorganisms to the most intricate multicellular organisms, the mechanisms of reproduction are as diverse as the life forms they sustain.
Join us as we embark on a journey to understand the intricacies of reproductive strategies, uncover the mysteries of embryonic development, and explore the marvels of sexual and asexual reproduction. As we unravel the complexities of this essential biological phenomenon, we will gain a deeper appreciation for the beauty and diversity that arise from the perpetuation of life.
Unit 14 Reproduction Long Questions
- 10th Class Pak Study Textbook
- 9th and 10th Class General Science Textbook
- Chapter No. 9 Notes 10th Chemistry
- Biology 10th Class Past Papers
- English Past Papers of 10th Class
Unit 14 Reproduction MCQ’s
Unit 14 Reproduction Short Questions
Question: What is reproduction?
Answer: Reproduction is defined as the production of individuals of the same species, ensuring the continuation of species and transmission of genetic material to the next generation.
Question: Why is reproduction essential for species?
Answer: Reproduction is essential for species because it ensures that the genetic material is passed on to the next generation and advantageous characteristics are transmitted through natural selection.
Question: What are the two basic types of reproduction?
Answer: The two basic types of reproduction are asexual reproduction and sexual reproduction.
Question: What is binary fission?
Answer: Binary fission is a method of asexual reproduction where an organism divides into two identical individuals. It is common in prokaryotes, unicellular eukaryotes, and some invertebrates.
Question: How does binary fission occur in bacteria?
Answer: In bacteria, DNA is duplicated, resulting in two copies of DNA. These copies move to opposite poles of the cell. The cell membrane invaginates, dividing the cytoplasm into two, and a new cell wall forms between the membranes, leading to the formation of two daughter bacteria.
Question: Can an individual live without reproducing?
Answer: Yes, an individual can live without reproducing, but a species cannot survive without reproduction.
Question: What is the difference between asexual and sexual reproduction?
Answer: Asexual reproduction involves simple cell division and produces genetically identical offspring. Sexual reproduction involves the fusion of male and female sex cells (gametes) and leads to genetic diversity among offspring.
Question: What is the significance of reproduction in maintaining a species?
Answer: Reproduction is crucial for the survival of a species as it allows genetic diversity and adaptation to changing environments.
Question: What are the types of organisms that undergo binary fission?
Answer: Binary fission occurs in prokaryotes (bacteria), many unicellular eukaryotes like protozoa, and some invertebrates.
Question: How do daughter cells form during binary fission in unicellular eukaryotes?
Answer: In unicellular eukaryotes, the parent organism’s nucleus divides into two through mitosis, followed by the division of cytoplasm. This results in the formation of two daughter cells of almost equal size.
Question: What is binary fission?
Answer: Binary fission is an asexual reproduction process in which an organism’s body is cut into two halves, and missing body parts are regenerated in both halves.
Question: Which organisms commonly reproduce asexually through binary fission?
Answer: Planaria and many echinoderms are examples of organisms that commonly reproduce asexually through binary fission.
Question: What is multiple fission?
Answer: Multiple fission is a type of asexual reproduction where a parent organism’s nucleus divides into many daughter nuclei by repeated divisions. This is followed by the division of cytoplasm into several parts, each enclosing one nucleus. Many daughter cells are formed from a single parent simultaneously.
Question: How does fragmentation work in certain worms?
Answer: As certain worms grow to full size, they spontaneously break up into 8 or 9 pieces. Each piece (fragment) develops into a mature worm, and this process is repeated. This process is called fragmentation.
Question: What is budding in asexual reproduction?
Answer: Budding is a type of asexual reproduction where a small outgrowth (bud) develops on the parent organism’s body. The bud enlarges, develops characteristics of the parent organism, and may eventually detach to become a new organism.
Question: Which organisms reproduce by budding?
Answer: Animals such as sponges, Hydra, and corals reproduce by means of budding.
Question: How do organisms like Rhizopus reproduce through spore formation?
Answer: Organisms like Rhizopus form thick-walled spore sacs called sporangia. Inside each sporangium, cells divide to form many daughter cells called spores. These spores are covered with a thick wall called cyst and can survive unfavorable conditions. When sporangia mature, they burst and release spores that can germinate under favorable conditions to develop into new organisms.
Question: Which bacterial species reproduce by forming endospores?
Answer: Some species of bacteria, such as Clostridium and Bacillus, reproduce by forming thick-walled spores called endospores inside bacterial cells.
Question: What is parthenogenesis?
Answer: Parthenogenesis is a form of asexual reproduction where an unfertilized egg develops into new offspring.
Question: Which organisms use parthenogenesis for reproduction?
Answer: Some fishes, frogs, and insects, as well as queen honeybees, use parthenogenesis for reproduction.
Question: How does parthenogenesis work in honeybees?
Answer: Queen honeybees lay eggs in honeycomb cells. Unfertilized eggs develop into haploid males (drones) through parthenogenesis, while fertilized eggs develop into diploid females (new queens and worker bees).
Question: What is vegetative propagation?
Answer: Vegetative propagation, also known as vegetative reproduction, is a process where new plants arise from vegetative parts such as roots, stems, or leaves.
Question: How do bulbs reproduce through vegetative propagation?
Answer: Bulbs are short underground stems surrounded by fleshy leaves. Adventitious roots emerge from the base, and shoots emerge from the top of the base, allowing reproduction.
Question: Which plants reproduce through corms?
Answer: Dasheen and garlic reproduce through corms, which are short and swollen underground stems.
Question: What are rhizomes, and how do they contribute to vegetative propagation?
Answer: Rhizomes are horizontal underground stems with nodes. Buds on the upper surface produce shoots, while adventitious roots grow from the lower surface. Ginger, ferns, and water lilies reproduce through rhizomes.
Question: How do stem tubers contribute to plant propagation?
Answer: Stem tubers, which are enlarged portions of underground stems, have buds called “eyes” that develop into shoots and roots. Plants like potatoes and yams reproduce through stem tubers.
Question: What are suckers in vegetative propagation?
Answer: Suckers are lateral stems close to the ground that grow underground and then turn up to produce new plants. Mint and Chrysanthemum reproduce through suckers.
Question: What is artificial vegetative propagation, and why is it used?
Answer: Artificial vegetative propagation is a method used by gardeners and farmers to increase the stock of plants. It involves human intervention to create new plants from vegetative parts.
Question: What are cuttings in plant propagation?
Answer: Cuttings are portions of plant stems or roots that have a meristematic region capable of growth. When placed in suitable conditions, they can develop into new plants.
Question: How are roses, ivy, and grapevines propagated?
Answer: Roses, ivy, and grapevines are propagated through stem cuttings.
Question: What is the advantage of vegetative propagation in terms of preserving beneficial characteristics?
Answer: Offsprings produced through vegetative propagation are genetically identical, preserving beneficial characteristics.
Question: What is cloning in terms of plant propagation?
Answer: Cloning involves producing identical offspring from a single parent using its vegetative tissue or cells through tissue culture.
Question: What is alternation of generations in the life cycle of plants?
Answer: Alternation of generations refers to the phenomenon where two different generations, sporophyte (diploid) and gametophyte (haploid), alternate during the plant’s life cycle.
Question: What are the components of a flower’s androecium?
Answer: The androecium is the male reproductive part of a flower and consists of stamens, each with a filament and an anther.
Question: What is produced within the anther of a flower’s stamen?
Answer: The anther produces pollen grains, which are haploid microspores.
Question: What structures make up the female reproductive part of a flower?
Answer: The gynoecium is the female reproductive part of a flower and consists of carpels (or pistils), each with an ovary, style, and stigma.
Question: What happens within the ovule of a flower’s carpel?
Answer: Inside each ovule, one haploid macrospore is produced through meiosis, which germinates into the female gametophyte generation.
Question: What is the significance of water in the sexual reproduction of mosses and ferns?
Answer: In mosses and ferns, water is required for the motile sperm to swim to the egg cells during sexual reproduction.
Question: What is pollination?
Answer: Pollination is the transfer of pollen grains from a flower’s anther to its stigma.
Question: What is the role of the pollen tube in fertilization?
Answer: The pollen tube grows through the style and ovary, enters the ovule, and releases sperm for fertilization.
Question: What is double fertilization?
Answer: Double fertilization involves two fusions: one sperm fuses with an egg to form a zygote, and another sperm fuses with a fusion nucleus to form an endosperm nucleus.
Question: How does self-pollination differ from cross-pollination?
Answer: Self-pollination involves transferring pollen within the same flower or to another flower of the same plant. Cross-pollination transfers pollen between flowers on different plants of the same species.
Question: What are some structural adaptations in insect-pollinated flowers?
Answer: Insect-pollinated flowers are generally large, brightly colored, produce nectar, and have stamens and stigmas enclosed inside a ring of petals.
Question: What is parthenocarpy?
Answer: Parthenocarpy is the development of fruit without fertilization, resulting in seedless fruits like bananas and seedless grapes.
Question: What are the three parts of an angiosperm seed?
Answer: The three parts of an angiosperm seed are the embryo, endosperm tissue, and seed coat.
Question: How does the seed coat protect the embryo?
Answer: The seed coat (testa) protects the embryo from mechanical injury and drying out.
Question: What is the purpose of the micropyle in the seed coat?
Answer: The micropyle is the opening through which the pollen tube entered the ovule, and the seed uses it for water absorption.
Question: Where does the stored food in angiosperm seeds come from?
Answer: The stored food in angiosperm seeds is derived from the endosperm tissue, which is rich in oil, starch, and protein.
Question: What is seed germination?
Answer: Seed germination is the process in which a seed embryo develops into a seedling.
Question: What causes the seed coat to split during germination?
Answer: Swelling of the embryo due to water absorption causes the seed coat to split during germination.
Question: Which structure emerges from the seed first?
Answer: The root, or radicle, is the first structure to emerge from the seed during germination.
Question: What are the two types of germination based on elongation of hypocotyl and epicotyl?
Answer: The two types of germination are epigeal germination and hypogeal germination.
Question: What are the important external conditions for seed germination?
Answer: The important external conditions for seed germination include water, oxygen, and favorable temperatures.
Question: What is the significance of absorbed water during seed germination?
Answer: Absorbed water is used for digestion of stored food and elongation of hypocotyl and epicotyl.
Question: What is the optimum temperature range for most plant seeds to germinate?
Answer: The optimum temperature range for the germination of most plant seeds is 25-30°C.
Question: What is the difference between epigeal and hypogeal germination?
Answer: In epigeal germination, the cotyledons are pulled above the ground, while in hypogeal germination, the cotyledons stay underground.
Question: What happens during gametogenesis?
Answer: Gametogenesis is the process in which diploid gamete mother cells undergo meiosis to form haploid gametes (sperm and egg cells).
Question: What is the difference between external and internal fertilization?
Answer: External fertilization occurs outside the body, often in aquatic environments, while internal fertilization occurs within the female reproductive tract.
Question: What is the male reproductive system of a rabbit composed of?
Answer: The male reproductive system of a rabbit consists of a pair of testes, associated ducts, and glands.
Question: Where are the testes located in a rabbit’s body?
Answer: The testes are located in a bag of skin called the scrotum that hangs below the body.
Question: What is semen composed of, and what do the associated glands add to it?
Answer: Semen consists of 10% sperms and 90% fluid. The associated glands add various secretions including nutrients from seminal vesicles, neutralizing secretion from the prostate gland, and lubrication from Cowper’s glands.
Question: Describe the female reproductive system of a rabbit.
Answer: The female reproductive system of a rabbit consists of ovaries, fallopian tubes, uterus, cervix, and vagina.
Question: Where is fertilization of egg cells by sperms believed to occur in rabbits?
Answer: Fertilization of egg cells by sperms in rabbits occurs in the fallopian tubes.
Question: What is the name of the connection established between the embryo and the uterus wall in a rabbit?
Answer: The connection established between the embryo and the uterus wall is called the placenta.
Question: What is the approximate gestation period for rabbit kits?
Answer: The gestation period for rabbit kits is approximately 30-32 days.
Question: What is overpopulation, and what problems can it lead to?
Answer: Overpopulation occurs when the population growth exceeds the carrying capacity of an area. It can lead to problems such as shortage of resources, deforestation, pollution, global warming, and high infant mortality rates.
Question: What is AIDS, and what causes it?
Answer: AIDS stands for Acquired Immune Deficiency Syndrome. It is caused by the human immunodeficiency virus (HIV) which destroys white blood cells, weakening the immune system.
Question: What are some ways through which HIV can be transmitted?
Answer: HIV can be transmitted through unprotected sexual activities, use of infected needles, and transfusion of infected blood.
Question: Give an introduction of Pakistan’s National AIDS Control Program.
Answer: Introduction of Pakistan’s National AIDS Control Program
The National AIDS Control Program (NACP) in Pakistan was established by the Federal Ministry of Health in 1987. Its primary objective is to prevent the transmission of HIV (Human Immunodeficiency Virus), promote safe blood transfusions, and reduce the prevalence of sexually transmitted diseases (STDs). The program works towards raising public awareness about HIV/AIDS, providing education and support, and implementing strategies to prevent the spread of the virus.
Question: What are the different ways by which prokaryotes, protozoans and fungi reproduce asexually?
Anwer: Ways of Asexual Reproduction
Prokaryotes: Prokaryotes, such as bacteria, reproduce asexually primarily through binary fission. In binary fission, a single prokaryotic cell divides into two identical daughter cells.
Protozoans: Protozoans, like Amoebae, can reproduce asexually through multiple fission. In multiple fission, a single parent cell divides into multiple daughter cells simultaneously.
Fungi: Fungi can reproduce asexually through methods like budding, where a small outgrowth (bud) forms on the parent organism and eventually separates to become a new individual. Fungi also reproduce through spore formation, where specialized structures called sporangia release spores that can develop into new individuals.
Question: Explain the different parts of the plant that help in natural vegetative propagation.
Answer: Plant Parts for Vegetative Propagation
Natural vegetative propagation involves various parts of the plant, including:
Bulbs: These are underground stems surrounded by fleshy leaves that store food and give rise to new plants.
Corms: Swollen underground stems that produce new plants from buds.
Rhizomes: Horizontal underground stems with nodes that produce shoots and roots, leading to new plant growth.
Stem Tubers: Enlarged portions of underground stems (rhizomes) that develop buds and grow into new plants.
Suckers: Lateral stems that grow near the ground and develop into new plants.
Leaves: Some plants can reproduce through leaves, where adventitious buds develop into new plants when leaves fall on the ground.
Question: Explain, how the epigeal and hypogeal germinations are different?
Answer: Difference Between Epigeal and Hypogeal Germination:
Epigeal Germination: During epigeal germination, the cotyledons emerge above the soil surface, and the shoot grows upward while the cotyledons remain exposed.
Hypogeal Germination: In hypogeal germination, the cotyledons remain below the soil surface, and the shoot emerges from the soil independently of the cotyledons.
Question: What conditions are necessary for the germination of seeds?
Answer: Conditions Necessary for Seed Germination
For successful seed germination, seeds require:
Water: To activate enzymes and metabolic processes.
Oxygen: For cellular respiration and energy production.
Proper Temperature: Suitable temperature conditions for enzyme activity.
Light: For some seeds, light is needed to initiate germination.
Suitable pH: Seeds usually germinate best in a slightly acidic to neutral pH environment.
Question: Outline the methods of asexual reproduction in animals.
Answer: Methods of Asexual Reproduction in Animals:
Some methods of asexual reproduction in animals include:
Binary Fission: Division of a single parent organism into two identical daughter organisms.
Budding: Formation of a bud on the parent organism that eventually detaches and develops into a new individual.
Fragmentation: Breaking of the parent organism into fragments, each of which can develop into a new individual.
Parthenogenesis: Development of an unfertilized egg into a new individual.
Question: Write a note on the male and female reproductive systems of rabbit.
Answer: The male reproductive system of a rabbit consists of a pair of testes located in the scrotum, which produce sperm. These sperm are transported through ducts such as the vas deferens, where they mix with secretions from glands to form semen. The female reproductive system includes ovaries that produce eggs, which are released into the fallopian tubes. After fertilization in the fallopian tubes, the zygote travels to the uterus where it develops into an embryo. The embryo is implanted in the uterine walls and eventually develops into a rabbit kit, which is born after a gestation period of around 30-32 days.
Question: Describe the processes of spermatogenesis and oogenesis.
Answer: Spermatogenesis is the process of sperm cell production in males. It takes place in the seminiferous tubules of the testes. Spermatogonial cells undergo several rounds of mitosis to produce spermatocytes. These spermatocytes then go through meiosis, resulting in the formation of four haploid spermatids, which further differentiate into mature sperm cells.
Oogenesis is the process of egg cell production in females. It begins before birth, as oogonia undergo mitosis to increase in number. During each menstrual cycle, one primary oocyte is selected to resume meiosis. Meiosis I occurs, resulting in one large secondary oocyte and a smaller polar body. The secondary oocyte then enters meiosis II, but it only completes this process if fertilization occurs. If fertilized, the secondary oocyte becomes the mature ovum, while the other polar body is discarded.
Question: Why do we consider that overpopulation is a global problem?
Answer: Overpopulation is considered a global problem due to its wide-ranging negative consequences. As the population grows beyond the Earth’s carrying capacity, there is increased pressure on limited resources such as fresh water, food, energy, and living space. Overpopulated areas often experience environmental degradation, deforestation, loss of biodiversity, and increased pollution. These factors contribute to climate change, habitat destruction, and declining quality of life. Overpopulation also leads to strain on healthcare, education, and social services, as well as higher rates of poverty and unemployment. To mitigate these issues, it’s crucial to manage population growth and promote sustainable practices.