The Class 10 Science syllabus encompasses the major and foundational concepts of Biology, Physics and Chemistry. One such important topic is Reproduction which is covered in detail in the chapter 8th titled “How do organisms reproduce”. In simple terms, reproduction means creating offsprings for the species to flourish. All living organisms strive for the evolution of their species in their own reproductive ways. This lesson elaborates on the elementary concepts of existence and answers the question of “how do we exist?’ in a scientific manner. Looking for How do Organisms Reproduce Class 10 notes and NCERT solutions? This blog brings you a comprehensive summary as well as important questions for this chapter.
This Blog Includes:
Are We All the Same?
While, in general, we may be easy to tell apart, but human beings have much in common with each other. Right from a pair of limbs, eyes, ears, and hands to the 206 bones that shape our body, we all have a standard structure. Infused in this very structure is DNA (DeoxyriboNucleic Acid), molecules existing in chromosomes that contain information about the inheritance of features through generations. The chapter on “How do organisms reproduce” in Class 10 notes that DNA varies from person to person; it’s the genetic element that affects our body structure, including morphology and physiology, ultimately leading to each human being’s uniqueness.
Importance of Variation
The process of reproduction involves DNA copying, which refers to the hereditary transfer of genes. DNA molecules define one’s adaptation to surroundings; the ability to adapt to changes in the external environment keeps evolving through generations. For instance, given the current climate change crisis, while many will get affected worldwide, species will gradually adapt to warmer temperatures. While studying the How do Organisms reproduce class 10 notes, you will learn about the various methods of reproduction that cause significant variations.
Modes of Reproduction by Single Organisms
- Fission: The process of division of a unicellular organism into two daughter cells is called fission. Different organisms show different types of fission. Leishmania possesses a whip-like structure, and the division of the parent cell happens by binary fission. Likewise, malarial parasites divide into many daughter cells resulting in multiple fissions.
- Fragmentation: In some multicellular organisms, the offsprings can be produced by simple division of cells on maturation. The divided cells grow into new individuals.
- Regeneration: The regeneration process occurs in differentiated organisms where a body part detaches from the parent cell and grows independently. For instance, hydra and planaria can be cut into many pieces, and then the offspring is produced from the parts.
- Budding: In the budding process, an extra body part grows as a detached bud when it matures; the separate part grows into a new individual.
- Vegetative Propagation: This refers to the formation of new plants under suitable conditions from the fruits, stems, and leave of parent plants. These plants develop faster than those planted by seeds and can bear fruits and flowers much earlier.
- Spore Formation: A spore is a tiny blob-on-a stick structure that travels from one site to another by external factors and grows into new plants until it comes in contact with favourable conditions.
The above modes of reproduction from unicellular organisms do not require another cell and are called Asexual Reproduction.
While the unicellular organisms can reproduce asexually, multicellular and highly differentiated organisms require two individuals for reproduction. Our Class 10 notes on How do Organisms reproduce have further summarized this mode of reproduction in plants and humans.
Sexual Reproduction in Flowering Plants
A flower contains the reproductive parts of angiosperms; if it includes both stamen and carpel, it is bisexual. In case it has either of the two, the plant is capable of asexual reproduction. The male reproductive part is called the stamen, which contains pollen grains of yellowish colour. The carpel is the female reproductive part, which sits in the middle of the flower. The process of sexual reproduction begins when the pollen grains land on the sticky upper part’s stigma.
The pollen now has to reach the female-germ cell present in the ovary, the bottom part. It moves through the style, which is the elongated part in the middle and fertilizes the egg in the ovule. After fertilization, the zygote divides several times to form an embryo. The seed contains an embryo that grows into a new plant under suitable conditions. The entire process of fertilization- pollen from Stamen to Stigma, and the ovary are called Germination.
Reproduction in Human Beings
We go through a variety of changes and growth in our bodies during our entire lifetime. Puberty is an age where the body starts to gain sexual maturity, and our organs begin to grow. The chapter on “How do organisms reproduce” also notes that the process of sexual reproduction involves the participation of two individuals to transfer germ-cells for fusion, which can grow into a new individual. Mammals carry the unique individual in their body for many days and then take care of them. The following sections elaborate upon the reproductive organs in male and female.
Male Reproductive Organ
As per the chapter on How do organisms reproduce in Class 10, the male reproductive system has the following parts:
- One pair of Testes: The two testicles are responsible for the production of sperms and testosterone- the primary male sex hormone. Each testis is located on either side of the scrotum with the end being secured by the spermatic cord.
- A system of ducts includes:
- Vas deferens or the sperm duct
- A system of glands includes:
- Seminal vesicles
- Prostate gland
- Cowper’s gland
- The Penis: The male organ used for sexual intercourse has 3 parts, i.e. the root, the body, and the shaft and is roughly cylindrical. It contains large pockets of erectile tissue that fills with blood on arousal and causes an erection.
You can further refer to the above image in our Class 10 notes for How do organisms reproduce. The testes are responsible for the preparation of germ cells and the transportation of germ cells for fusion. The sperm formation occurs in the testes, which are outside the body as they require low temperatures. The sperm then moves through the vas deferens. The sperm is generally a genetic material head with a tail that moves towards the female germ cell. On reaching the female germ cell, it fertilizes the egg and forms a zygote.
Female Reproductive Organ
As per the Class 10 chapter on How do organisms reproduce, the female reproductive system consists of the following parts:
- One pair of ovaries: The two ovaries lie to the extreme right and left of the uterus. During the process of ovulation, the produce, store and release eggs in fallopian tubes. They are part of the endocrine system and produce the female hormone- estrogen.
- One pair of fallopian tubes or oviducts: The fallopian tubes are tine passageways attached to the side of the uterus.
- A uterus/womb: The uterus has a thick lining and a muscular wall that accommodate the growing features. The muscles of the uterus are one of the strongest in the female body.
- A vagina: Also known as the birth canal, the vagina is a muscular hollow tube. The muscular feature helps the vagina to expand and contract, making it highly flexible. The walls of the vagina are lined with mucous to keep it moist.
The ovaries consist of thousands of eggs. On maturing, these eggs are carried to the womb by the fallopian tube. The sperms enter the female body through the vaginal passage, from which they travel to the oviduct to fertilize the egg. The zygote formed sticks to the lining of the uterus and starts dividing. The embryo lives on the uterus’ lining and derives its nutrition from the mother’s blood using the placenta. The development of a child inside the womb takes nine months. If the egg doesn’t fertilize, it lives for one day and then is broken from the lining and comes out through the vagina as blood and mucous. This cycle of blood flow is called menstruation, which lasts about two to eight days in females.
We’ve seen that unicellular organisms reproduce by budding, regeneration, fragmentation, and vegetative propagation. The main event involved in asexual reproduction is the division of the parent cell into two or more daughter cells that eventually develop into new individuals. More advanced organisms have high complexity in cell structure and require specialized cells for reproduction. The germ cells reach the egg for fusion, which creates a zygote. The zygote develops into an embryo, which develops into a new individual after detaching—the asexual and sexual reproduction results in the vast population of plants, animals, and human beings.
Important Questions for Class 10 How do Organisms Reproduce
Now that you have gone through the Class 10 notes for How do organisms reproduce, here are some important exam questions and answers for this chapter.
- How do unicellular organisms produce offspring?
The unicellular organisms divide into different daughter cells that develop into new individuals.
- How does pollen reach the ovary spore formation?
The pollen travels from the stamen to the stigma by air or wind. The pollen has the male germ cell, which travels through the style to fertilize the ovaries’ female cells.
- How does budding generate a new organism?
In budding, a body part outgrows by a repetitive generation of cells at a site that acts as a bud. The bud detaches on maturation and then develops into a new organism.
- How does asexual reproduction differ from sexual reproduction?
In asexual reproduction, a single parent reproduces by the division of cells. In sexual reproduction, two individuals participate in fertilizing the egg and forming an embryo. This embryo grows into a new individual.
- Why do testes grow outside the body?
Testes are responsible for sperm formation that require low temperature. Hence, to maintain the temperature levels, testes grow in the outside direction.
We hope this blog helped you understand the details of reproduction through How do organisms reproduce class 10 notes. Unsure about finding the right stream after 10th? Our Leverage Edu experts are here to guide you in selecting the right stream as per your aspirations and interests! Sign up for a free session with us now.