11. Consider the following statements regarding bones in the human body:
- They consist of 80% solid matter and20% water.
- Solid matter in the bones is made mainly of cartilage.
- Impregnation of salts including carbonates and phosphates of lime imparts hardness to the bones.
- In old age, the proportion of lime decreases and bones become brittle and break easily.
Of these statements:
[A] 1,2 and 3 are correct
[B] 2 and 4 are correct
[C] 2 and 3 are correct
[D] 1, 2, 3 and 4 are correct
Show Answer
Correct Answer: D [1, 2, 3 and 4 are correct]
Notes:
All of them are correct.
Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen – “organic” referring to materials produced as a result of the human body – and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.
12. The bats are able to fly in dark since their wings produce which of the following waves?
[A] Infrared rays
[B] Ultrasonic waves
[C] Sound waves
[D] Ultraviolet rays
Show Answer
Correct Answer: B [Ultrasonic waves]
Notes:
Bats can fly in dark because they. Bat echolocation is very much similar to a SONAR and is a perceptual system where ultrasonic sounds are emitted specifically to produce echoes.
13. What is the term known as a giant growth of algae?
[A] Panic boom
[B] Algal boom
[C] Herbal boom
[D] Patkai boom
Show Answer
Correct Answer: B [Algal boom
]
Notes:
A massive growth or rapid increase in the population of algae in water is known as algal boom.
14. Which of the following class of leucoplasts is responsible for fat storage?
[A] Amyloplast
[B] Proteinoplasts
[C] Aleuroplasts
[D] Elaioplasts
Show Answer
Correct Answer: D [Elaioplasts]
Notes:
Leucoplast is colorless or non-pigmented in nature. It is used for storage. Amyloplasts store starch, proteinoplasts and aleuroplasts as well as modify proteins.
15. Which of the following viruses is not linked to human cancer?
[A] Hepatitis C virus
[B] Hepatitis B virus
[C] Varicella-Zoster virus
[D] Herpes simplex virus type 2
Show Answer
Correct Answer: C [Varicella-Zoster virus]
Notes:
Hepatitis C, Hepatitis B and Herpes simplex virus type 2 viruses which are linked to human cancer.
16. In cell culture, the measles virus can lead to which of the following?
[A] nuclear pyknosis
[B] transformation of cells
[C] syncytium formation
[D] rounding and aggregation of cells
Show Answer
Correct Answer: C [syncytium formation]
Notes:
In cell culture, the measles virus can lead to syncytium formation.
17. Viruses reproduce in living cells by__?
[A] replication
[B] duplication
[C] multiplication
[D] all of these
Show Answer
Correct Answer: A [replication]
Notes:
DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.
18. Dicotyledonous branches are found in which of the following?
[A] Fern
[B] Funaria
[C] Liverworts
[D] Marchantia
Show Answer
Correct Answer: C [Liverworts]
Notes:
Dicotyledonous branches are found in Liverworts. Liverworts are also moss-like land plants that do not have a vascular system.
19. In which of the following colour, rate of photosynthesis is minimum?
[A] Red
[B] Blue
[C] Green
[D] Yellow
Show Answer
Correct Answer: D [Yellow]
Notes:
The rate of photosynthesis is minimum in yellow colour and maximum in red colour. This happens because in the absorption spectrum, the red and blue colour gets absorbed and the majority of green light gets reflected.
20. What is the main mode of nutrition in plants?
[A] autotrophic mode
[B] heterotrophic mode
[C] Parasitic mode
[D] Saprophytic mode
Show Answer
Correct Answer: A [autotrophic mode]
Notes:
The main mode of nutrition in plants is the autotrophic mode of nutrition and leaves of plants contain chlorophyll which helps them to make their own food.
