Roman Saini is teaching live on Unacademy Plus
Q211. An ecosystem is made up of; 1. Biotic factors 2. Abiotic factors Choose the correct code. a. b. c. Both 1 and 2 d. None of the above 1 only 2 only
Answer: c Explanation: An ecosystem is made of all the plants, animals and microorganisms (biotic components) in an area along with non- living components such as climate, soil, river deltas (abiotic components) etc.
Q212. What do you understand by the Red Data Book? 1. It is the document established for documenting rare and endangered 2. It is the document established for documenting rare and endangered 3. It is the document established for documenting rare and endangered species of animals. species of plants species of fungi Choose the correct code. a. 1 only b. 2 only c. 1 and 2 only d. 1, 2 and3
Answer:d Explanation: It is the document established for documenting rare and endangered species of animals, plants and fungi.
213. Which of the following is the largest cells) in nature? largest cell(s) in nature? a. Neuron cells. b. Ostrich egg c. Elephants zygote d Muscle cells
Answer:b Explanation: An egg is a single cell and ostrich's egg is the largest egg.
Q214. Consider the following statements: 1. Coloured bodies called plastids are found in the plant cells 2. Green plastids containing chlorophyll are called green- Choose the correct statement/ statements. only plasts. a. 1only 2 only c. Both 1 and 2 d. None of the above
Answer: a Explanation: Green plastids containing chlorophyll are called chloroplasts. Plastids are absent in animal cells and so is cell wall. chloroplasts. Plastids are absen tontaining chlorophyll are ca
Q215. External fertilization is seen in; 1. Frogs 2. Starfish 3. Fishes 4. In-vitro fertilization Choose the correct code. 1 only b.2 and 3 only C. C. d. 1, 2, 3 and 4 4 only
Answer: d Explanation: Fertilization which takes place inside the female body is called internal fertilization. It occurs in many animals like humans, cows, dogs and hens. Fertilization in which the fusion of a male and a female gamete takes place outside the body of the female is called external fertilization. It is very common in aquatic animals such as fish, starfish, frogs, toads etc Some women are unable to bear babies because of oviduct block and sperms cannot reach the egg for fertilization. In such cases, doctors collect freshly released egg and sperms and keep them together for a few hours for IVF (fertilization outside the body). In case fertilization occurs, the zygote is allowed to develop for about a week and then it is placed in the mother's uterus. Complete development takes place in the uterus and the baby is born like any other baby. Babies born through this technique are called test-tube babies.
Q216. Which of the following is an oviparous animal? a. Hen b. Whale Bat Cow C.
Answer: a Explanation: The animals which give birth to young ones are called viviparous animals. Those animals which lay eggs are called oviparous animals. Whale, bat and cow are mammals and all mammals are viviparous.
Answer:b Explanation: Self-explanatory Cloning of an animal was successfully performed for the first time by lan Wilmut et al. They cloned successfully a sheep named Dolly Dolly was born on 5th July 1996 and was the first mammal to be cloned.
Q219. Why endocrine glands are also called as ductless glands? a. Because they release their secretion into ducts of other b. Because they release their secretions into blood stream. d. Because ducts in endocrine glands are not well developed organs C It is a misnomer as endocrine glands have ducts. c. is a misnomer as endocrine glands have ducts.
Answer: a Explanation: females have two X chromosomes while males have one X and one Y chromosome
0221. Which of the following is known as the master gland in animal body? a. Liver b. Pituitary gland c. Thyroid gland d. Adrenal gland
Answer:b Explanation: Pituitary gland controls the activity of other endocrine glands so it is also known as the master gland.
Q223. Consider the following statements. 1. Friction opposes the relative motion between two surfaces in contact. 2 t acts on the moving surface only. Choose the correct statement. a. b. 2 only c. Both 1 and 2 d. None of the above 1 only
0224. Which of the following cannot help in reducing noise pollution? a. Wooden rooms b. Planting more trees along the roads C. Legal measures d. Reducing the pitch of all man-made instruments
0225. Sound cannot be transmitted through; a. Vacuum b. Solid mediumm c. Liquid medium d. Air
Answer: a Explanation: Sound needs a medium (solid, liquid or gaseous) to be transmitted through. It can't be transmitted through vacuum.