1. Which of the following bacteria forms an endosymbiotic nitrogen fixing association with roots of legumes that helps in Nitrogen Fixation?
[A] Clostridium
[B] Rhizobium
[C] Salmonella
[D] Staphylococcus
Show Answer
Correct Answer: B [Rhizobium]
Notes:
Rhizobium Found in roots of legumes, like Peas, grams, Pulses etc, where it fixes atmospheric nitrogen as ammonia, which is then converted into useful amino acid.
2. In which of the following diseases , nerve cells are affected?
[A] Tetanus
[B] Polio
[C] Whooping Cough
[D] Diphtheria
Show Answer
Correct Answer: B [Polio]
Notes:
Nerve cells are affected in Polio. Polio also known as poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis.
3. In which of the following conditions a person is born with both ovarian and testicular tissues i.e. both female & male organs?
[A] Swyer syndrome
[B] Penile agenesis
[C] Polyorchidism
[D] Hermaphroditism
Show Answer
Correct Answer: D [Hermaphroditism]
Notes:
A hermaphrodite is an organism that has complete or partial reproductive organs and produces gametes normally associated with both male and female sexes. It has both ovarian and testicular tissues.
4. Gargling with a solution of table salt is known to provide relief for a sore throat because ____ ?
[A] It kills bacteria
[B] It works as analgesic
[C] It dehydrates water from inflammatory tissues by Osmosis
[D] Placebo effect
Show Answer
Correct Answer: C [It dehydrates water from inflammatory tissues by Osmosis]
Notes:
Gargling with salt water provides relief for a sore throat primarily because it dehydrates water from inflammatory tissues through osmosis. This process reduces swelling and discomfort. Saltwater creates a hypertonic solution, drawing excess fluid out of swollen tissues, which can alleviate pain and irritation. Additionally, salt has mild antibacterial properties, but its primary benefit in this context is osmotic dehydration.
5. Which among the following usually regulates breathing in Humans?
[A] The number of red blood cells
[B] The amount of haemoglobin in the blood
[C] Inherent genetic control
[D] CO2 levels and pH sensors
Show Answer
Correct Answer: D [ CO2 levels and pH sensors]
Notes:
The breathing rate is controlled by the medulla in the brain, which is primarily sensitive to CO2 levels in the blood.
6. Urea is one of the major constituents of Urine in our body. In which among the following organs, Urea is formed?
[A] Kidneys
[B] Urinary Bladder
[C] Urethra
[D] Liver
Show Answer
Correct Answer: D [ Liver]
Notes:
Urea is a nitrogenous waste that is produced in the liver; urine is produced in the kidney. We note here that Uric acid is excreted as a crystal to conserve water by many terrestrial animals. However, humans and earthworms release nitrogenous waste in the form of urea.
7. Identify the organelle with the help of given information:
- It is a double membrane organelle.
- It is found only in eukaryotic cells.
- It is responsible for ATP production.
Select the correct option from codes given below:
[A] Centriole
[B] Lysosome
[C] Endoplasmic Reticulum
[D] Mitochondria
Show Answer
Correct Answer: D [ Mitochondria]
Notes:The organelle is the “Mitochondrion.” Here’s how the information matches:
- It has a double membrane: Mitochondria are enclosed by a double membrane structure.
- Found only in eukaryotic cells: Mitochondria are a characteristic feature of eukaryotic cells and are not found in prokaryotic cells.
- Responsible for ATP production: Mitochondria are often referred to as the “powerhouses” of the cell because they are responsible for producing ATP (adenosine triphosphate), which is the primary energy currency of the cell.
So, the correct answer is the “Mitochondrion.”
8. Which of the following branches of Biology is not associated with snakes ?
[A] Herpetology
[B] Ophiology
[C] Serpentology
[D] Saurology
Show Answer
Correct Answer: D [Saurology]
Notes:
All of the three –Herpetology, Ophiology and Serpentology are associated to the study of snakes.While Saurology is associated to the study of Lizards. Thus Option [D] is correct.
9. Which of the following taxonomic level is same for man, monkey and tiger?
[A] Genus
[B] Family
[C] Order
[D] Class
Show Answer
Correct Answer: D [Class]
Notes:
The order Primata includes monkey, gorilla and man and the order Carnivora includes lion, tiger, cat and dog. These two orders are the members of the same class called Mammalia. So, man, monkey and tiger are in the same class.
10. Which organs have different basic structures, yet present a similarity in appearance and perform analogous functions?
[A] Kidney and liver
[B] Heart and lungs
[C] Wings of a bat and a bird
[D] Brain and spinal cord
Show Answer
Correct Answer: C [Wings of a bat and a bird]
Notes:
This is a unique example of convergent evolution in which organs can serve similar purposes but originate from very different original structures. Wings of a bat and bird serve the same purpose, flight, yet they have different underlying structures, resulting from a different evolutionary path.
