Q1. __________ is present in unisexual flower.
Androecium or gynoecium is present in unisexual flower.
Updated on: 2026-03-31 | Author: Rahul Patil
Androecium or gynoecium is present in unisexual flower.
Monozygotic twins are formed from a single embryo.
Surrogacy modern remedial technique is used if there is a problem in implantation of embryo in the uterus.
Childless couples can have a child with the help of advance medical techniques like surrogacy, sperm bank and IVF.
Women having problems with implantation of the embryo in the uterus can have a child with the help of surrogacy technique. In this technique, oocyte is collected from the concerned woman and fertilized in a test tube with the help of sperms collected from her husband. Embryo formed from fertilization is implanted in another woman (surrogate mother), having a normal uterus.
In sperm banks, semen is collected from the sperm donors after their physical and medical check-up and stored. Semen sample from the sperm bank is used to fertilize the oocyte of the female partner of the concerned couple. The resultant embryo is implanted in the uterus of the same woman.
Couples, in which males have problems in sperm production, can have a child with the help of this technique.
Childless couples having problems like less sperm count, obstacles in oviduct, etc., can use IVF technique. In this technique, fertilization is brought about in the test tube and the embryo formed is implanted in the woman’s uterus at an appropriate time.
If a piece of wet bread or bhakri kept in a humid place for 2-3 days, then filamentous fungi can be seen.
Generally, fungi such as Mucor and Rhizopus are found on wet bread or bhakri.
Fungi like Mucor have a filamentous body. It has sporangia. Once the spores are formed, sporangia burst to release the spores.
These spores germinate in moist and warm place and new fungal colonies are formed.
Accessory whorls : Calyx and corolla : : essential whorls : Androecium and gynoecium
Amoeba : fission : : Hydra : Budding
Asexual reproduction occurs by mitotic cell division.
At the time of birth, there are 2 to 4 million oocytes in the ovary of a female foetus.
Bisexual : Hibiscus : : Unisexual : Papaya
Calyx : Sepals : : Corolla : Petals
Growth of follicles present in the ovary occurs under the effect of follicle stimulating hormone. This follicle secretes estrogen. Endometrium of uterus grows/regenerates under the effect of estrogen.
Under the effect of luteinizing hormone, fully grown up follicle bursts, ovulation occurs and corpus luteum is formed from remaining part of follicle. It secretes progesterone and estrogen. Under the effect of these hormones, glands of endometrium of uterus are activated and it becomes ready for implantation.
| Sex/Gender | Reasons of infertility |
| Female | Irregularity in menstrual cycle, difficulties in oocyte production, obstacles in the oviduct, difficulties in implantation in uterus |
| Male | Absence of sperms in the semen, slow movement of sperms, anomalies in the sperms |
The formation of a zygote by the union of male and female gametes is known as fertilization.
The process of asexual reproduction in which the parent body breaks into many pieces or fragments and the fragments develop into mature filaments is known as fragmentation.
A specialised axis or branch over which flowers are produced or borne in definite manner is known as inflorescence.
A type of asexual reproduction in which the body of an organism breaks into parts and thereafter each part regenerates the remaining part of the body and new organisms are formed is known as regeneration.
Vegetative reproduction is a type of asexual reproduction in plants, where new plants are produced from the vegetative parts like roots, stems, leaves, and buds.
In self-pollination, only one or two flowers borne on the same plant are involved, whereas in cross-pollination two flowers borne on two plants of same species are involved.
| Asexual reproduction | Sexual reproduction | |
| i. | Reproduction that occurs with the help of somatic cells is called as asexual reproduction. | Reproduction that occurs with the help of two germ cells is called sexual reproduction. |
| ii. | This is uniparental reproduction, thus both male and female parent are not necessary. | Male and female parents are necessary for sexual reproduction. |
| iii. | This reproduction occurs with the help of mitosis only. | This reproduction involves both mitosis and meiosis types of cell division. |
| iv. | The new individual formed by this method is genetically identical to its parent. | New individual formed by this method is genetically different from parents. |
| v. | Asexual reproduction occurs in different individuals by various methods like binary fission, multiple fission, budding, fragmentation, regeneration, vegetative propagation, spore formation, etc. | In all individuals, sexual reproduction occurs by gamete formation and fertilization. |
| Binary fission | Multiple fission | |
| i) | Living cells divide to form two similar daughter cells. | Living cells divide into many daughter cells. |
| ii) | Cyst formation does not occur. | Cyst formation occurs. |
| iii) | Nucleus divides into two halves. | Nucleus divides into many nuclei. |
| iv) | It occurs in Amoeba under favourable conditions. | It occurs in Amoeba during unfavourable conditions. |
| v) | Examples: Amoeba, Paramecium | Example: Plasmodium |
Asexual reproduction is the process by which a plant gives rise to a new plant without producing seeds or spores. Asexual reproduction in plants occurs by vegetative propagation. The development of a new plant from the vegetative part of a plant-like stem, root, or leaf is known as vegetative propagation.
The various methods of vegetative propagation are:
From underground stem: A potato plant has an underground stem known as the tuber. It has many buds called eyes. A vegetative bud consists of a short stem, around which immature overlapping leaves are present in a folded state.
A bud can give rise to a new plant through asexual reproduction.
Rhizome: The underground stem of ginger is known as the rhizome which is capable of giving rise to a new plant. A corm is an underground stem as found in Gladiolus. It can also be used for vegetative propagation.
Through leaves: Leaves perform the function of photosynthesis. However, they can take part in asexual reproduction as well. In some plants, leaves can give rise to a new plant asexually.
For example, the leaves of the plant Bryophyllum contain buds on its margins. These buds give rise to a new plant through asexual reproduction.
From aerial stem: In certain plants, a slender stem arises from the base of the plant and touches the soil, it develops roots and buds at the point of contact with the soil and gives rise to new plants. When the new plant is old enough the stem connecting it to the parent plant withers away.
IVF is a technique in which fertilization is brought about in the test tube. Sperm is injected into the ovum using a micropipette.
The embryo formed after fertilization is implanted in the uterus of a woman at the appropriate time.
Childless couples, who have problems like less sperm count, obstacles in the oviduct, etc., can use IVF technique for having a child.
Importance of reproduction:
It helps in the process of evolution.
It also helps in existence/survival of a species of an organism.
Process of fertilization in humans:
Formation of zygote by union of sperm and ovum is called as fertilization.
Fertilization is internal in humans. Semen is ejaculated in vagina during copulation.
Sperms, in the numbers of few millions, start their journey by the route of vagina – uterus – oviduct.
One of those few million sperms fertilizes the only ovum present in the oviduct.
Process of fertilization in plants:
Stigma becomes sticky during pollination.
The pollen grain germinates over the stigma and gives rise to pollen tube.
Pollen tube carries two male gametes which are released near egg cell present in the embryo sac.
One male gamete fuses with a female gamete giving rise to zygote. The second male gamete fuses with two polar nuclei giving rise to endosperm. This is called as double fertilization.
Two main processes involved in sexual reproduction:
Gamete formation: In this, meiotic division occurs due to which chromosome number is reduced to half. As a result, haploid gametes are formed (2n → n).
Fertilization: Haploid male gamete (n) fuses with the haploid female gamete (n) to form a diploid zygote (2n).
Binary fission
Papaya
Bartholin glands
Explanation:
Prostate glands, Cowper’s gland, Seminal vesicle are related to the reproductive system in males while Bartholin glands are present in the woman's reproduction system.
Pollens
Prostate gland
Anther
Follicle stimulating hormone : Development of oocyte : : Luteinizing hormone : Ovulation
Generally, every month, 1 ovum is released in the abdominal cavity alternately from each ovary.
The pollen grain germinates over the stigma and gives rise to pollen tube.
The pollen tube bursts and releases two male gametes in the embryo sac.
One male gamete fuses with the egg cell to form the zygote, whereas the second male gamete fuses with two polar nuclei in the embryo sac to form an endosperm.
Since, in flowering plants, the process of fertilization occurs twice in the same embryo sac, by two male gametes, it is called as double fertilization.
Flower is structural unit of sexual reproduction in plants. It consists of four floral whorls as calyx, corolla, androecium and gynoecium; arranged in sequence from outside to inside. Androecium and gynoecium are called 'essential whorls' because they perform the function of reproduction whereas calyx and corolla are called as 'accessory whorls' because they are responsible for protection of inner whorls.
A female has millions of oocytes at the time of birth and new ova are not formed thereafter.
Their ability to divide diminishes and they may not be able to complete meiotic division properly.
Fertilization of such oocytes may result in the production of genetic abnormalities (like Down syndrome) in offspring.
Sexual reproduction involves two parents i.e. male parent and female parent.
The male gamete coming from a male parent fuses with a female gamete of a female parent to form a zygote which develops into an embryo and then into a new individual.
Thus, the new individual always has the recombined genes of both the parents.
The natural cessation of menstruation that occurs between the age of 45-50 years is known as menopause.
Menopause occurs as the secretion of hormones controlling the functions of the female reproductive system either stops or becomes irregular.
Testosterone, Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH)
Progesterone, Estrogen
Testes contain numerous seminiferous tubules. Germ cells present in the tubules divide by meiosis to produce sperms.
Genetic variation helps the organisms to adjust with the changing environment and thereby to maintain their existence. Due to this, plants and animals can save themselves from being extinct.
Semen is formed of sperms and secretions of seminal glands, prostate gland and Cowper’s glands.
A female has millions of oocytes at the time of birth and new ova are not formed thereafter.
Their ability to divide diminishes and they may not be able to complete meiotic division properly.
Fertilization of such oocytes may result in the production of genetic abnormalities (like Down’s syndrome) in offsprings.
Implantation of the embryo occurs in uterus.
In humans, sperm production occurs in the organ testes.
Explanation:
The male reproductive system of humans consists of testes, various ducts, and glands. Sperm are produced in the testes of men from the beginning of maturation (puberty) till death.
In humans, there are 23 pairs of chromosomes.
In meiosis, the number of chromosomes becomes half.
In Vitro Fertilization (IVF), surrogacy, sperm banks
Binary fission
Multiple fission
Budding
Monozygotic and dizygotic twins.
Fertilization of ovum occurs in oviduct.
After fertilization, embryo gets implanted in uterus.
Gynoecium (Carpel): It is an essential whorl. It is consists of stigma, style and ovary. It acts as a female reproductive part of the flower.
It is responsible for the production of female gametes.
Androecium (Stamen): It is an essential whorl. It is consists of anther and filament. It acts as a male reproductive part of the flower.
It is responsible for the production of male gametes.
Calyx and corolla: Calyx and corolla are accessory whorls. They are responsible for the protection of inner (essential) whorls.
Pedicel: Pedicel is a small stalk which supports the flower.
The given diagram represents regeneration which is a method of asexual reproduction in some multicellular organisms.
In this type of asexual reproduction, the body of an organism breaks into parts and thereafter each part regenerates the remaining part of the body and new organisms are formed.
In Planaria, when the body is cut, each part formed, develops into a whole new organism.
The type of reproduction shown in the diagram is vegetative propagation.
Sweet potato - Vegetative propagation in sweet potato occurs by roots (adventitious buds on roots).
Bryophyllum - Vegetative propagation in Bryophyllum occurs by buds on the leaf margin.
Potato - Vegetative propagation in potatoes is occurs with the help of eyes (bud on potato) present on tuber.
Pollen grains are formed by meiosis division in locules of anthers.
True
True
Pregnant mother supplies nourishment to her foetus through placenta.
Through the process of reproduction living organisms are able to maintain the continuity of their own species.
Budding and parthenogenesis are the methods of asexual reproduction in animals.
Vegetative propagation, fragmentation, budding, spore formation are the different methods of reproduction in plants.
Cloning is a modern breeding method being researched in developed animals.
True
The human male reproductive system consists of
Testes
Scrotum
Epididymis
Vas Deferens
Seminal Vesicles
Prostate Gland
Bulbourethral Glands
Urethra
Penis
The human female reproductive system consists of vagina, uterus, oviduct and ovaries.
Menstrual cycle is controlled by four hormones:
Follicle-stimulating hormone (FSH),
Luteinizing hormone (LH),
Estrogen and
Progesterone
Childless couples can have a child with the help of advance medical techniques like surrogacy, sperm bank and IVF.
Women having problems with implantation of the embryo in the uterus can have a child with the help of surrogacy technique. In this technique, oocyte is collected from the concerned woman and fertilized in a test tube with the help of sperms collected from her husband. Embryo formed from fertilization is implanted in another woman (surrogate mother), having a normal uterus.
In sperm banks, semen is collected from the sperm donors after their physical and medical check-up and stored. Semen sample from the sperm bank is used to fertilize the oocyte of the female partner of the concerned couple. The resultant embryo is implanted in the uterus of the same woman.
Couples, in which males have problems in sperm production, can have a child with the help of this technique.
Childless couples having problems like less sperm count, obstacles in oviduct, etc., can use IVF technique. In this technique, fertilization is brought about in the test tube and the embryo formed is implanted in the woman’s uterus at an appropriate time.
transverse binary fission
The similarity or difference between the organisms of a species depends upon whether these individuals are formed by sexual reproduction or asexual reproduction.
Zygote utilizes food stored in endosperm of seed and a new plantlet is formed. This is called as seed germination.
The term heredity may be defined as the transmission of genetically based characteristics from parents to offspring.
Gamete formation is a process in which haploid gametes are formed by meiotic division.
Formation of new organism of same species by earlier existing organism is called as reproduction. Reproduction is one of the various important characters of living organisms.
Female reproductive system undergoes some changes (that prepare the uterus for pregnancy) at puberty and those changes repeat at an interval of every 28-30 days. Such repetitive changes are called the menstrual cycle.
The process represented in the given figure in vitro fertilization (Fertilization in a test tube).
IVF is a technique in which fertilization is brought about in the test tube. Sperm is injected into the ovum using a micropipette.
The embryo formed after fertilization is implanted in the uterus of a woman at the appropriate time.
Childless couples, who have problems like less sperm count, obstacles in oviduct, etc., can use IVF technique for having a child.
Also, there will be no crossing over of homologous chromosomes. Thus, there will be no variations with respect to the changing environment in progeny to maintain their existence, which may lead to the extinction of species.
Pollination occurs with the help of abiotic agents like wind, water and biotic agents like insects and other animals.
Binary fission
After fertilization, the ovule develops into seed and ovary into fruit.
It is important to maintain good reproductive health to be safe from various sexually transmitted diseases.
Precautions to maintain reproductive health are as follows:
Keep private parts clean.
During the menstrual cycle, girls should maintain genital hygiene.
Avoid situations, where there is a risk of being infected with sexually transmitted diseases.
Study the relevant and scientific information about matters related to sexuality.
Seek help from reproductive health care facilities without any hesitation.
In Hydra, under favourable conditions, the regenerative cells of body wall are used for reproduction in the process of budding.
When Hydra reaches maturity, the body wall begins to form an outgrowth from the stalk of the adult. It is called bud. This bud develops into a young Hydra.
The dermal layers and the digestive cavity of the young Hydra are continuous with that of the parent Hydra. The young Hydra gets nourishment from the parent.
When the young Hydra is sufficiently developed, it breaks off from the parent Hydra. Then, it leads an independent life.
Various reasons of infertility are as follows:
In case of women, irregularity in menstrual cycle, difficulties in oocyte production, obstacles in the oviduct, difficulties in implantation in uterus and many other reasons are responsible for this.
Absence of sperms in the semen, slow movement of sperms, anomalies in the sperms are the reasons in case of males.
Syphilis, Gonorrhea, AIDS
The given figure represents the menstrual cycle in females.
Uterus and ovaries are involved in menstrual cycle.
Menstrual cycle is controlled by four hormones: follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen and progesterone.
After at an interval of every 28-30 days changes happen again.
The given figure represents the human male reproductive system.
A: Seminal vesicle
B: Prostate gland
C: Urinogenital duct
D: Testis
The part labelled as ‘D’ is testis which is responsible for sperm production.
Semen is formed of sperms and secretions of seminal glands, prostate gland and Cowper’s glands.
In human females, ovaries release eggs and secrete progesterone and estrogen.
In plants, ovary present at the base of the carpel contains ovules. Embryo sac is formed in each ovule by meiosis.
Semen is ejaculated out through the penis.
Secretions of seminal vesicles constitute the semen.
Sepals are responsible for the protection of inner whorls.
Budding