Question 7: Consider the following statements:

1. Lagrange points, or L-points, allow for orbits that are much farther away and do not orbit Earth directly.
2. Lagrange points are specific points far out in space where the gravitational fields of Earth and the Sun combine in such a way that spacecraft that orbit them remain stable.
3. These points are situated at the distance of approximately 10000 km.
4. LISA Pathfinder is located at one of the Lagrange points between Sun and Earth.

Which of the following statements is/are true?

1. 1,2 and 3
2. 2,3 and 4
3. 1,2 and 4
4. 1,2,3 and 4

Correct Answer: C

Explanation

• Lagrange points, or L-points, allow for orbits that are much, much farther away (over a million kilometers) and do not orbit Earth directly.
• These are specific points far out in space where the gravitational fields of Earth and the Sun combine in such a way that spacecraft that orbit them remain stable and can thus be ‘anchored’ relative to Earth.
• If a spacecraft was launched to other points in space very distant from Earth, they would naturally fall into an orbit around the Sun, and those spacecrafts would soon end up far from Earth, making communication difficult. Instead, spacecraft launched to these special L-points stay fixed and remain close to Earth with minimal effort without going into a different orbit.
• The most used L-points are L1 and L2. These are both four times farther away from Earth than the Moon – 5 million km, compared to GEO’s 36 000 km – but that is still only approximately 1% of the distance of Earth from the Sun.
• For example, the solar telescope SOHO and LISA Pathfinder at the Sun-Earth L1 point; Herschel, Planck, Gaia, Euclid, Plato, Ariel, JWST, and the Athena telescope are or will be at the Sun-Earth L2 point.

Question 8: Consider the following statements:

1. Red blood cells are usually round and flexible, so they move easily through blood vessels.
2. Sickle cell anemia occurs due to a genetic mutation that causes haemoglobin in red blood cells to clump together.

Which of the following statements is/are true?

1. 1 only
2. 2 only
3. 1 and 2 only
4. Neither 1 nor 2

Correct Answer: C

Explanation

Sickle cell anemia:

• Occurs due to a genetic mutation that causes Haemoglobin in red blood cells (RBCs) to clump together.
• Affects the shape of RBCs.
• RBCs are usually round and flexible, so they move easily through blood vessels.
• In sickle cell Anemia, some RBCs are shaped like sickles or crescent moons.
• They become rigid and sticky, which can slow or block blood flow.

Question 9: Consider the following statements:

1. A retrovirus is a virus that uses DNA as its genomic material.
2. AIDS is associated with a retrovirus.
3. A virus cannot replicate alone.

Which of the following statements is/are true?

1. 1 only
2. 3 only
3. 2 and 3 only
4. 1,2 and 3

Correct Answer: C

Explanation

• A retrovirus is a virus that uses RNA as its genomic material.
• Upon infection with a retrovirus, a cell converts the retroviral RNA into DNA, which in turn is inserted into the DNA of the host cell.
• The cell then produces more retroviruses, which infect other cells. Many retroviruses are associated with diseases, including AIDS and some forms of cancer.
• A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of Often, a virus ends up killing the host cell in the process, causing damage to the host organism.

Question 10: Consider the following statements with respect to LVM3-M2 launch vehicle:

1. It is a 3-stage launch vehicle consisting of Solid Rocket Boosters and Core Liquid Stage and Cryogenic Upper Stage.
2. It has a carrying capacity of about 80 tones to low earth orbit (LEO) and 40 tones to geo transfer orbit (GTO).

Which of the following statements is/are true?

1. 1 only
2. 2 only
3. 1 and 2 only
4. Neither 1 nor 2

Correct Answer: A

Explanation

• LVM3-M2 mission was the first dedicated commercial satellite mission of New Space India Limited (NSIL). NSIL, a public-sector enterprise under Department of Space, is enabling Indian industries to take up high technology space-related activities and is catering to emerging global commercial small satellite launch service market.

LVM3-M2 launch vehicle (earlier called Geosynchronous Launch Vehicle Mark III or GSLV- MK3):

• It is a 3-stage launch vehicle consisting of Solid Rocket Boosters and Core Liquid Stage and Cryogenic Upper Stage.
• It has a carrying capacity of about 8 tones to low earth orbit (LEO) and 4 tones to geo transfer orbit (GTO).
• It is ISRO’s second rocket for global commercial market, after its Polar Satellite Launch vehicle (PSLV).