July 2022

Reproduction in Animals: Question and Answers CBSE/NCERT For  Class 8th Chapter 9

Define test-tube baby?
Ans: In-vitro fertilisation, or IVF, is a method used by women who have blocked oviducts and are unable to conceive naturally to create a test-tube baby. For IVF (in vitro fertilisation), doctors take freshly released eggs and sperm and keep them combined for a few hours (fertilisation outside the body). The zygote is given a week to develop if fertilisation occurs before being inserted into the mother’s uterus. Like any other infant, the baby grows completely inside the uterus before being born. Test-tube babies are those born in this manner. This is a misleading term because babies cannot develop in test tubes.

Dendrobium: Distribution, Characteristics, Plant Morphology, Growth, and Flowering

It is found throughout many tropical and subtropical areas, including Southeast Asia, where there are hundreds of species, and Vietnam, where there are over 100 species, all of which are extensively dispersed. With more than 16,000 species, Dendrobium is the second-largest orchid genus (Puchooa, 2004). Major producers of Dendrobium orchids include Thailand, Taiwan, China, the Philippines, Germany, the United States, Japan, and India. The majority of Dendrobium species are epiphytic, sympodial orchids that are native to subtropical and tropical areas. This genus is well-known for its ability to produce cut flowers. Commercial Dendrobium cultivation is widespread in the states of Karnataka, Kerela, Tamil Nadu, and Andhra Pradesh.

Ixora coccinea: Classification, Origin, Characteristics, Phytochemistry and Traditional Uses

Ixora coccinea Linn. (Rubiaceae), sometimes called red ixora, scarlet ixora, jungle of geranium, jungle flame, flaming love, and flame of the woods. The species name “coccinea” means crimson, while the genus name “Ixora” is thought to come from the Sanskrit word “ikvana,” which is named after a Malaysian deity. It may also be derived from the term “Iswara,” which is another name for Lord Shiva, to whom the flowers are dedicated during worship. All plant parts have been shown to have medicinal value in Ayurveda, the conventional Indian medical system, as well as in several indigenous medical systems in Sri Lanka and India. The plant produces chickpea-sized red to scarlet coloured fruits that are also eaten as food, particularly by Indian villages and tribal communities’ young inhabitants. There are over 500 species of tropical evergreen trees and bushes there. Ixora is a plant that is frequently found in subtropical regions of the United States, including Florida. Only a small number of the about 500 species in the genus Ixora are regularly grown in gardens.

Some Natural Phenomena: Question and Answers CBSE/NCERT for Class 8 Science Chapter 15

Describe three things you’ll do in the event of an earthquake?
Ans: If you are in an earthquake, you should follow these precautions: (i) Take cover under a table if you are confined to your home or another structure; do not move until the shaking stops. Use your arms to cover your head. Don’t use the elevator. (ii) Avoid standing close to fans, bookcases, mirrors, hanging plants, or windows. (iii) Get out of your house or school and go somewhere open. (iv) If you’re outside, stay clear of tall buildings, trees, signs, poles, and electric poles and wires. (v) Avoid riding in a car or a bus.

Monkeypox virus: Disease Agent, Background, Characteristics, Common Human Exposure Routes, and Treatment

A member of the genus Orthopoxvirus, which also includes camelpox, cowpox, vaccinia, and variola viruses, is the monkeypox virus. The World Health Organization confirmed in 1980 that the virus is the main orthopoxvirus infecting human populations since smallpox elimination. In the resource-limited endemic regions where monkeypox is found, clinical detection, diagnosis, and prevention still pose difficulties. Studies carried out before the conclusion of smallpox eradication provide information on monkeypox epidemiology, but additional evaluations are required now that routine smallpox vaccination has finished and there is associated declining herd immunity. To further inform preventative strategies and gain a better understanding of the animal species involved in virus transmission and maintenance, basic ecological studies are also required

Crop Production and Management: Classification Cultivation and Agricultural Implements For Class 8th CBSE/NCERT

Plough: This is used for tilling the ground, fertilizing crops, getting rid of weeds, scraping the ground, etc. A pair of bulls or other animals are used to pull this tool, which is composed of wood or iron.
Hoe: This straightforward tool is used to clear weeds from the soil and loosen it.
Cultivator: Today, a tractor-driven cultivator is used for ploughing. It saves time and labour.
Before sowing, high-quality seeds are chosen. Clean, nutritious, and of a nice variety, good quality seeds are those. If we are given seeds to choose from, we must put all of the seeds in a pail of water and thoroughly agitate them. Few seeds will float in the water, and the majority of the seeds will settle at the bottom of the bucket. Seeds with damage become hollow and lighter as a result. They float on water as a result.
Seed Drill
In modern times, tractors’ hoes are utilized to spread seeds. This device evenly distributes the seeds at the correct depths.

Royal Poinciana: Gastroprotective Activity, Wound Healing Activity, Antidiarrhoeal Activity, Nutritional and Haemagglutination Properties

Delonix regia Rafin flower ethanolic extract was obtained and tested for gastroprotective efficacy in an experimental model of caused ulcers. In the pylorus ligation-produced gastric ulceration model, the different parameters including ulcer index, pH of gastric juice, percentage protection in all models, and stomach volume, free acidity, and total acidity were tracked. The ethanolic floral extract of Delonix regia Rafin had dose-dependent gastroprotective properties (Singh and Kumar, 2014).

Royal Poinciana: Classification, History, Occurrence, Characteristics, Phytoconstituents, and Economic Importance

The Generic name “Delonix” comes from the Greek words “delos” (visible) and “onyx” (claw) about the flower’s prominently clawed petals. The Latin word “regis” (meaning “royal, regal, and magnificent”) is the source of the particular name “regia” (Singh et al., 2014). Nature has long been a vast source of therapeutic compounds dating back to the Stone Age. For both traditional and modern medicine, plants have historically been the most abundant source of raw ingredients. Phytochemicals are largely responsible for plants’ therapeutic efficacy. The flame of the forest or flame tree is a species of almost evergreen tree with broad, open, umbrella-shaped crowns. They are essentially planting metabolites that are produced independently in every area of a plant’s body and that have definite physiological effects on mammals (Hait et al., 2018). It is known by a variety of names in every region and nation, including Chura (Bengali), Radha (Bengali), Royal, Flamboyant, Poinciana (French), Gulmohar, Shima, sunkesula (Hindi), mayirkonrai, Punjabi (Tamil), Flamboyant flame tree, Gold mohur, flame tree, Peacock flower, Gul mohr, and Royal poinciana (English). This tree needs light to flourish, but in the dark, it develops slowly and unevenly. It thrives in areas with both abundant and infrequent rainfall. Only in regions with a long and noticeable dry season are trees deciduous (Sharma and Arora, 2015).

CELL: Discovery, Structure, Functions, Questions, and Answers for Class 8th Science Chapter 8 NCERT/ CBSE

Every known living entity has a cell as its fundamental structural and functional element. It is frequently referred to as the foundation of life since it is the tiniest piece of life that may be considered a living entity. There are roughly 10 trillion cells in an adult human. Only under a microscope can one see the majority of plant and animal cells, which range in size from 1 to 100 m. In 1665, Robert Hooke found the cell. All organisms are made up of one or more cells, According to the cell theory, which was first put forth in 1839 by Matthias Jakob Schleiden and Theodor Schwann. It also states that all cells are descended from preexisting cells, that vital functions of an organism take place within cells, and that all cells contain the genetic information required to control cell functions and pass information to the next generation of cells.