Q1. What is a stem cell?
(a) A cell that can only differentiate into one specific cell type.
(b) A specialized cell with limited regenerative capabilities.
(c) A cell with the unique ability to differentiate into various cell types.
(c) A cell with the unique ability to differentiate into various cell types.
Ans: (c)
Explanation:
- Stem cells have the unique ability to differentiate into a variety of cell types, including specialized cells like muscle cells, nerve cells, and blood cells. This characteristic is known as pluripotency.
Q2. What are the differences between embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs)?
(a) Embryonic stem cells are derived from the inner cell mass of embryos, while induced pluripotent stem cells are derived from adult tissues.
(b) Both embryonic stem cells and induced pluripotent stem cells are derived from adult tissues.
(c) Induced pluripotent stem cells are derived from the inner cell mass of embryos, while embryonic stem cells are reprogrammed adult cells.
(d) Embryonic stem cells and induced pluripotent stem cells are essentially the same and can be used interchangeably.
Ans: (a)
Explanation:
- Embryonic stem cells are pluripotent cells derived from the inner cell mass of embryos. In contrast, induced pluripotent stem cells are created by reprogramming adult cells, often skin cells, to express genes that are typically active in embryonic stem cells. The source of the cells is different in these two cases.
Q3. Which one of the following statements about greenhouse gas is correct?
(a) Greenhouse gases are only emitted by human activities and not present naturally.
(b) Greenhouse gases include water vapor, carbon dioxide, methane, and ozone.
(c) Greenhouse gases have a cooling effect on the Earth’s atmosphere.
(d) Greenhouse gases primarily contribute to air pollution.
Ans: (b)
Explanation:
- Context: The World Meteorological Organisation (WMO) reported that greenhouse gas (GHG) concentrations in the Earth’s atmosphere reached record levels in 2022, primarily driven by the use of fossil fuels.
- Greenhouse gases are a group of gases that trap heat in the Earth’s atmosphere, contributing to the greenhouse effect. Water vapor, carbon dioxide, methane, and ozone are among the key greenhouse gases.
Q4. What is the ‘Igla-S’?
(a) A type of tropical fruit found in Southeast Asia.
(b) A Russian surface-to-air missile system.
(c) An international space station module.
(d) A rare species of butterfly native to South America.
Ans: (b)
Explanation:
- Context: Russia has announced its plan to supply the Igla-S man-portable air defence missile system to the Indian armed forces.
About Igla-S:
- The Igla-S is a man-portable air defence missile system (MANPADS) developed by Russia. MANPADS are shoulder-launched surface-to-air missiles designed to be operated by an individual soldier. The Igla-S is an upgraded variant of the earlier Igla system
Q5. Consider the following countries:
- Ethiopia
- Djibouti
- Kenya
- Eritrea
How many of the above nations share a land border with Somalia?
(a) Only one
(b) Only two
(c) Only three
(d) All four
Ans: (c)
Explanation:
About Somalia:
- It is a country in the Horn of Africa. The country is bordered by Ethiopia to the west, Djibouti to the northwest, the Gulf of Aden to the north, the Indian Ocean to the east, and Kenya to the southwest. Somalia has the longest coastline on Africa’s
