1. Complete the following chart.
Answer:-
Asexual reproduction
- Reproduction that occurs with the help of somatic cells is called as asexual reproduction.
- No exchange of genetic material occurs.
- This reproduction occurs with the help of mitosis only.
- Only one parent is required for asexual reproduction.
- Asexual reproduction occurs in different individuals by various methods like binary fission, multiple fission, budding, fragmentation, regeneration, vegetative propagation, spore production, etc.
Sexual reproduction
- Reproduction that occurs with the help of gametes is called as sexual reproduction.
- Exchange of genetic material occurs through fertilization.
- This reproduction occurs with the help of meiosis and mitosis.
- Male and female parent are necessary for sexual reproduction.
- New individual formed by this method is genetically different from parents, due to the combination of genetic material from both parents and the random selection of chromosomes during meiosis.
2. Fill in the blanks.
a. In humans, sperm production occurs in the organ —————-.
b. In humans, —— chromosome is responsible for maleness.
c. In male and female reproductive system of human, ————- gland is same.
d. Implantation of embryo occurs in ——
e. ———- type of reproduction occurs without fusion of gametes.
f. Body breaks up into several fragments and each fragment starts to live as a new individual. This is — — — — — — — type of reproduction.
g. Pollen grains are formed by — —– — — — division in locules of anthers.
Answer:-
a. In humans, sperm production occurs in the organ testes.
b. In humans, Y chromosome is responsible for maleness.
c. In male and female reproductive system of human, ovary gland is same.
d. Implantation of embryo occurs in uterus
e. Asexual type of reproduction occurs without fusion of gametes.
f. Body breaks up into several fragments and each fragment starts to live as a new individual. This is fragmentation type of reproduction.
g. Pollen grains are formed by meiotic division in locules of anthers.
3. Complete the paragraph with the help of words given in the bracket.
(Luteinizing hormone, endometrium of uterus, follicle stimulating hormone, estrogen, progesterone, corpus luteum)
Growth of follicles present in the ovary occurs under the effect of —– This follicle secretes estrogen. — — – — — — grows / regenerates under the effect of estrogen. Under the effect of — —, fully grown up follicle bursts, ovulation occurs and — — — — is formed from remaining part of follicle. It secrets —— — — and — — — — –. Under the effect of these hormones, glands of — — — — are activated and it becomes ready for implantation.
Answer:-
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 secrets progesterone and estrogen. Under the effect of these hormones, glands of endometrium are activated and it becomes ready for implantation.
4. Answer the following questions in short.
a. Explain with examples types of asexual reproduction in unicellular organism.
Ans:-
Types of asexual reproduction in unicellular organisms include binary fission, budding, and fragmentation. Binary fission is the process where a single cell divides into two identical daughter cells. An example of this is the reproduction of bacteria. Budding is where a small outgrowth or bud forms on the parent cell, which eventually separates to form a new individual. An example of this is yeast reproduction. Fragmentation is where an organism breaks into multiple pieces, each of which can grow into a new individual. An example of this is in some types of algae
b. Explain the concept of IVF.
Ans:-
IVF stands for In-Vitro Fertilization. It is a process in which the egg and sperm are fertilized outside the body, in a laboratory setting. The fertilized egg, called an embryo, is then transferred to the woman’s uterus with the hope that it will implant and result in a pregnancy
c. Which precautions will you follow to maintain the reproductive health?
Ans:- To maintain reproductive health, one should follow precautions such as practicing safe sex, regular gynecological check-ups, healthy diet, exercise and avoiding smoking and alcohol.
d. What is menstrual cycle? Describe it in brief.
Ans:_ The menstrual cycle is the series of physiological changes that occur in the female reproductive system, including the ovaries, uterus and vagina, in preparation for pregnancy. The cycle typically lasts 28 days and is divided into three phases: the follicular phase, ovulation, and the luteal phase. The follicular phase is when the ovary prepares to release an egg, ovulation is when the egg is released, and the luteal phase is when the uterus prepares to receive a fertilized egg. If the egg is not fertilized, the lining of the uterus is shed, resulting in menstruation.
5. In case of sexual reproduction, new-born show similarities about characters. Explain this statement with suitable examples.
Answer:_
In case of sexual reproduction, new-born show similarities about characters because they inherit genetic information from both of their parents. This genetic information is passed down through the egg and sperm cells, which contain half of the genetic information needed to form a new individual. When the egg and sperm cells unite during fertilization, they combine their genetic information to form a complete set of genetic instructions for the new organism.
For example, a child may inherit their mother’s brown eyes and their father’s curly hair. This is because the genetic information for eye color and hair texture are located on different chromosomes and are passed down from each parent during fertilization. Similarly, a child may inherit their father’s height and their mother’s intelligence because these traits are also determined by specific genes that are inherited from each parent.
In summary, during sexual reproduction, offspring inherits half of their genetic information from each parent, this genetic information controls the physical and behavioral characteristics of the offspring, as a result, new-born show similarities about characters.
6. Sketch the labelled diagrams.
a. Human male reproductive system.
b. Human female reproductive system.
c. Flower with its sexual reproductive organs.
d. Menstrual cycle.
7. Give the names.
a. Hormones related with male reproductive system.
b. Hormones secreted by ovary of female reproductive system.
c. Types of twins.
d. Any two sexual diseases.
e. Methods of family planning.
Answer:- a. Hormones related with male reproductive system are testosterone and luteinizing hormone (LH).
b. Hormones secreted by ovary of female reproductive system are estrogen and progesterone.
c. Types of twins are fraternal and identical twins. Fraternal twins occur when two separate eggs are fertilized by two separate sperm, and they develop in the same womb. Identical twins occur when a single egg is fertilized by a single sperm, and then divides into two separate embryos, which develop in the same womb.
d. Two sexual diseases are gonorrhea and syphilis
e. Methods of family planning include natural family planning, barrier methods, hormonal methods, intrauterine devices (IUDs), and sterilization.
8. Gender of child is determined by the male partner of couple. Explain with reasons whether this statement is true or false.
Answer:-
This statement is false. The gender of the child is determined by the presence or absence of certain sex chromosomes in the sperm. The sperm that carries an X chromosome will result in a female offspring, and the sperm that carries a Y chromosome will result in a male offspring. The sex chromosomes are inherited from the parents, and the father contributes the sperm that will determine the sex of the child. However, it is not determined by the male partner alone. The mother also plays a crucial role as she contributes one of the two chromosomes that will define the sex of the baby. Therefore, the gender of the child is not determined solely by the male partner of the couple but by a combination of genetic material from both parents.
9. Explain asexual reproduction in plants.
Answer:-
Asexual reproduction in plants refers to the process by which new plants are produced without the involvement of seeds or spores. There are several different ways that plants can reproduce asexually, including:
- Vegetative reproduction: This is the most common form of asexual reproduction in plants. It involves the growth of new plants from vegetative parts such as roots, stems, or leaves. For example, strawberry plants produce runners, which are long stems that grow along the ground. These runners develop new plants at their tips, which are genetically identical to the parent plant.
- Bulbils: Some plants, such as lilies, develop small bulbs or bulbils at the base of the stem. These bulbils will grow into new plants that are genetically identical to the parent plant.
- Tubers: Some plants, such as potatoes, produce underground storage organs called tubers. These tubers can develop into new plants that are genetically identical to the parent plant.
- Cloning: Cloning is a method of asexual reproduction that is used to produce identical copies of a plant. This is done by taking a cutting from a parent plant and planting it in soil or water. Once the cutting develops roots, it can be planted in soil and grown into a new plant.
- Division: Some plants can be divided into multiple pieces, each of which can grow into a new plant. This is particularly common among perennials, such as hostas and iris.
In summary, Asexual reproduction in plants can happen through vegetative reproduction, bulbils, tubers, cloning, and division. These methods all involve the production of new plants from vegetative parts of the parent plant, rather than from seeds or spores. These new plants produced are genetically identical to the parent plant.
10. Modern techniques like surrogate mother, sperm bank and IVF technique will help the human beings. Justify this statement
Answer:-
Modern techniques like surrogacy, sperm banking, and IVF can help human beings by providing alternative ways for individuals and couples to have biological children.
- Surrogacy: Surrogacy is a process in which a woman carries and delivers a baby for another person or couple. This can be especially helpful for individuals or couples who are unable to conceive or carry a pregnancy to term due to medical issues.
- Sperm banking: Sperm banking is a process in which sperm are collected and frozen for later use. This can be helpful for individuals or couples who may not have a partner at the time they wish to conceive, or for men who wish to preserve their fertility due to medical treatments.
- IVF (In-Vitro Fertilization): IVF is a process in which eggs are removed from a woman’s ovaries and fertilized with sperm in a laboratory. The resulting embryos are then implanted into the uterus. This can be helpful for individuals or couples who are unable to conceive due to infertility or other medical issues.
In summary, these modern techniques can provide individuals and couples with the opportunity to have biological children, even if they may not be able to conceive naturally. They also provide options for individuals and couples facing infertility, medical conditions, and other issues that may prevent them from having children through traditional means.
11. Explain sexual reproduction in plants
Answer:-
Sexual reproduction in plants refers to the process by which new plants are produced through the fusion of male and female reproductive cells. The main organs involved in sexual reproduction in plants are the stamen (male reproductive organ) and the pistil (female reproductive organ).
- Pollination: Pollination is the process by which pollen is transferred from the anther (part of the stamen) to the stigma (part of the pistil). Pollination can occur through a variety of means, including wind, water, and animals. Once the pollen reaches the stigma, it will grow down the style (the stem-like structure connecting the stigma and ovary) to the ovary, where fertilization takes place.
- Fertilization: Fertilization is the process by which the male and female reproductive cells, called pollen and ovules, fuse to form a zygote. This process results in the production of a seed, which contains the genetic information from both the male and female parent plants.
- Seed development: After fertilization, the seed will develop within the ovary. Once the seed is fully developed, it will be released from the ovary and can be used to grow a new plant.
- Germination: Germination is the process by which the seed sprouts and a new plant begins to grow. This process usually involves the seed absorbing water and breaking down the stored food to provide energy for the new plant to grow.
In summary, sexual reproduction in plants is the process by which new plants are produced through the fusion of male and female reproductive cells. This process involves pollination, fertilization, seed development, and germination. The process results in offspring that have genetic characteristics of both parent plants.