Chapter-8, How Do Organisms Reproduce

Explanation:

DNA (deoxyribonucleic acid) is the genetic component found in all cells of all animals. DNA conveys genetic information from one generation to the next, assisting in the creation of animals of its own kind. DNA copying is necessary to inherit traits from parents. Any changes in DNA copying will result in the formation of new species.

Explanation:

The reason why diversity is advantageous to species rather than individuals is that climate changes may have a severe influence on species, making survival difficult. For example, if the temperature of the water body rises, certain types of microbes may perish. This might cause environmental disruption. Hence, variety benefits species rather than individuals.

Explanation:

Binary fission occurs when a single cell splits into two equal parts. Binary fission is seen in bacteria and amoeba.

Multiple fission occurs when a single cell splits into numerous daughter cells at the same time. Multiple fission is seen in algae and sporozoans.

Explanation:

The following are the ways in which an organism will profit from spore reproduction:

• The number of spores generated by a single sporangium would be enormous.

• To minimise rivalry in one location, spores can be transferred to other locations via air.

• The spores have robust walls to protect themselves from dehydration in harsh environments.

Explanation:

Organisms at greater complexity levels cannot regenerate new people because their organ systems are organised at various levels. All of these organ systems are interrelated and function in tandem. They can regenerate some of their missing bodily components, such as skin, blood, and muscles, but they cannot give birth to new people.

Explanation:

The following are some of the benefits of using vegetative propagation to grow certain plants:

• Since crops such as oranges, bananas, and pineapples lack viable seeds, vegetative propagation can be utilized.

• It is a faster, cheaper, and easier way to raise crops.

• It can be utilized in areas where seed germination is unsuccessful.

• A variety of high quality can be retained.

Explanation:

Since it transmits genetic information from parents to children, DNA copying is a vital aspect of the reproduction process. Certain chemical processes make a copy of DNA, resulting in two copies of DNA. Together with the extra cellular structure, DNA copying occurs, followed by cell division into two cells.

Explanation:

Pollination is defined as the transport of pollen from the anther to the stigma. The procedure is carried out with the assistance of pollinators like air, water, and insects.

The merging of male and female gametes is defined as fertilization. It occurs in the ovule and results in the creation of a zygote.

Explanation:

Secretions from the seminal vesicles and the prostate gland serve to lubricate sperms and provide a fluid medium for the smooth movement of sperms. These secretions also contain nutrients such as fructose, calcium, and enzymes.

Explanation:

The following are the changes observed in girls throughout puberty:

• Hair begins to develop in the vaginal region.

• Other sites of hair development include the underarms, face, hands, and legs.

• The uterus and ovaries grow in size.

• The size of the breast rises, followed by the darkening of the nipple skin near the breast's tip.

• The start of the menstrual period.

• The appearance of pimples when the skin secretes more oil.

Explanation:

After fertilization, the uterine lining thickens. The blood supply is adequate to nourish the developing fetus. The placenta is a unique tissue inserted in the uterine wall that assists the embryo in receiving nutrients from the mother's tissue. The placenta has villi on one side and blood space on the other. This distance allows for a vast space between the mother and the embryo, as well as waste elimination.

Explanation:

No, Copper-T cannot prevent the contact of bodily fluids. As a result, it cannot protect women from sexually transmitted infections.

Explanation:

(b) Yeast

The incentive is an illustration of asexual reduplication that occurs via budding. A  bitsy projection is formed on the parent cell, which develops to full size and forms a  cub. The son nexus divides and migrates to the son cell in the parent cell. The cub detaches from the mama's body at the base by generating condensation. This budding process continues to induce a chain of cub cells. The mama cell is more compact than the son cell.

Explanation:

(c) Vas deferens

Vas deferens is a male reproductive system organ. It is a muscular tube that connects the epididymis to the pelvic cavity. It is located behind the bladder. Its purpose is to carry mature sperm to the urethra. It also transports urine outside the body.

Explanation:

(d) Pollen grains.

An anther is a part of the male reproductive organ of a flower called the stamen. It is a sac-like structure located at the tip of the stamen, which contains pollen grains. Pollen grains are the male gametophytes of flowering plants, which carry the male reproductive cells needed for fertilization of the female gametophyte (located in the pistil) to produce seeds.

Explanation:

The following are the benefits of sexual reproduction:

• The offspring possesses the personalities of both parents.

• Because there are more varieties, the species' existence is assured.

• The offspring are adaptable to environmental changes.

• It is also beneficial to human health.

Explanation:

The following are the functions of the testis in humans:

• Besides from sperm production, it also creates androgens, which are male hormones.

• They also generate testosterone, which is responsible for males' secondary sexual characteristics.

Explanation:

Menstruation occurs as a part of the menstrual cycle, which is a natural process that occurs in the female reproductive system of humans and some other animals. The main purpose of the menstrual cycle is to prepare the female body for pregnancy.

During each menstrual cycle, the uterus (womb) prepares for a possible pregnancy by thickening its lining. If pregnancy does not occur, the thickened lining is not needed and is shed from the uterus in a process called menstruation. Menstruation occurs approximately every 28 days and typically lasts for 3-7 days.

The shedding of the uterine lining during menstruation is caused by a decrease in levels of estrogen and progesterone, two hormones that regulate the menstrual cycle. The decrease in hormone levels triggers the release of prostaglandins, which cause the uterus to contract and expel the lining.

Explanation:

Explanation:

The following are the many techniques of contraception:

• Natural technique: The basic goal of this approach is to avoid sperm and ovum contact. This can be accomplished by avoiding mating from the tenth to the seventeenth day of the menstrual cycle. Because ovulation is predicted around this time, there is a significant likelihood of conception.

• Barrier technique: The meeting of sperm and ovum is prevented in this procedure by utilizing a barrier. These obstacles are available to both men and women. Condoms for both men and women, diaphragms for women, a cervical cap, and a contraceptive sponge for women.

• Oral contraceptives are tablets that are taken orally. These tablets contain a little number of hormones that inhibit the eggs, preventing fertilization.

• Implants and surgical technique: Contraceptive devices such as copper-T or a loop can be employed in this manner to prevent the meeting of sperm and ovum. The fallopian tubes are closed in females to prevent the passage of eggs, while the vas deferens are stopped in men to prevent the flow of sperm.

Explanation:

Fission, budding, and other mechanisms of reproduction are used by unicellular organisms. The cell divides into two daughter cells at this point, and the process of cell division continues.

In contrast, multicellular creatures have a separate organ system for reproduction. Vegetative propagation, spore formation, and other mechanisms of reproduction are used by multicellular organisms.

Sexual reproduction occurs in more sophisticated creatures such as humans and animals.

Explanation:

Reproduction is the process through which current species produce more of the same sort of species. This is done to preserve the population of that species as well as to pass on their kind to future generations. Stability is maintained by keeping an eye on the birth and death rates.

Explanation:

The following are the reasons for using contraception:

• Population control,

• To avert an unintended pregnancy,

• To prevent the spread of sexually transmitted illnesses.