After fertilisation, the uterine lining becomes thicker. The growing embryo is well-nourished by the blood flow. The placenta, a unique tissue that is embedded in the uterine wall and helps the embryo in obtaining nutrition from the mother’s tissue, is present during pregnancy. The placenta has blood space on the mother’s side and frequently applied …
How does the embryo get nourishment inside the mother’s body? Read More »
Following are the changes seen in girls at the time of puberty: (a) Hair growth appears in the genital area or growth of pubic hair.(b) Hair growth in the body in different areas like underarms, face, hands and legs.(c) The size of the uterus and ovary increases.(d) The size of the mammary glands (breast) increases …
Q. What are the changes seen in girls at the time of puberty? Read More »
Solution: With the help of secretions from the seminal vesicles and the prostate gland, sperms are lubricated and given a fluid medium for easier movement. These secretions also contain certain enzymes, calcium, and fructose, which are nutrients
Solution : Pollination – the process of transfer of pollens grain from anther to stigma. The process takes place with the help of pollinators like air, water and animals. Fertilization – the fusion of male gamete with female gametes. It takes place in the ovule and leads to the formation of a zygote.
Solution : The advantages that an organism will have if it uses spores for reproduction are as follows: Several spores produced in one sporangium would be large.To avoid competition in one place, spores can be distributed to faraway places with the help of air.To prevent dehydration under unfavourable conditions, the spores are covered by thick …
Q.How will an organism be benefited if it reproduced if reproduces through spores ? Read More »
Solution: Binary fission is the process by which a single cell divides into two equal-sizesize parts. Binary fission is found, for example, in bacteria and amoebas. Multiple fission occurs when a single cell divides into many daughter cells simultaneously. Sporozoans and algae are two examples of multiple fission.
Solution : The reason why the variation is beneficial to the species rather than individuals is that sometimes the climatic changes have a drastic effect on the species, which makes their survival difficult. For example, if the temperature of the water body increases, there might be certain species of microorganisms might die. This may result …
Solution: DNA – Deoxyribonucleic acid is the genetic material that is present in the cells of all organisms. DNA carries genetic information from one generation to the next, which helps in the development of organisms of its sort. For traits from parents to be inherited, DNA copying is necessary. New species can arise as a …
Q. What is the importance of DNA copying in reproduction? Read More »
Solution: Flower (i) The plant’s primary reproductive organ is the flower.(ii) The calyx and corolla are located in the two outer whorls of its four whorls.(iii) The androecium, or male part of the flower, and the gynoecium, or female part of the flower, are located in the inner two whorls. (iv) The main structure of …
Solution : Definition : flower is the reproductive structure of angiospermic plants. As popularly used, the term “flower” especially applies when part or all of the reproductive structure , the coloured part of a plant or tree from which seeds or fruit grow Diagram of a flower Functions of flower : Functions of parts of …
