Category: Class 11 Biology Objective Questions

Biology Quiz for NEET Exam on “Mechanism of Breathing-2”.

1. Which of the following is the most important muscular structure in respiratory system of human?
a) External intercoastal muscle
b) Internal intercoastal muscle
c) Diaphgram
d) Vertebral column
Answer: c
Clarification: Diaphgram is the most important muscular structure in respiratory system of human. At the time of inspiration, diaphgram contracts leading to increase in thoracic volume whereas during expiration it relaxes causing decrease in thoracic volume.

2. Air that remains in lungs after most powerful expiration is _______
a) inspiratory air
b) residual air
c) dead space air
d) tidal air
Answer: b
Clarification: Residual air is the volume of air remaining in the lungs even after most forceful expiration. It cannot be expelled out of the lungs. Its value on an average in adult man is approximately 1200 ml.

3. Contraction in diaphgram causes increase in thoracic volume in the _____
a) dorso-ventral axis
b) antero-posterior axis
c) dorso-posterior axis
d) antero-ventral axis
Answer: b
Clarification: At the time of inspiration diaphgram contracts leading to increase in thoracic volume in the anterior posterior axis. Whereas movement of sternum causes increment in antero-ventral direction.

4. Where is the respiratory rhythm center is located?
a) Medulla region
b) Aortic arch
c) Pons region
d) Carotid artery
Answer: a
Clarification: The respiratory rhythm center in the Medulla is primarily responsible for the regulation. Dorsal respiratory group(DRG) generate the basic respiratory rhythm whereas the ventral respiratory(VRG) which remains inactive during normal respiration.

5. What happens to RBC of human blood at high altitude?
a) Decrease in size
b) Decrease in number
c) Increase in size
d) Increase in number
Answer: d
Clarification: At high altitude oxygen pressure is lower thus lungs have to take in more oxygen to fulfill the demands of the body. Therefore, an increase in RBC helps to transport more oxygen to the body parts.

6. Strength of inspiration and expiration can be increased with the help of_______
a) abdominal muscles
b) external intercoastal muscle
c) diaphragm
d) internal intercoastal muscle
Answer: a
Clarification: Abdominal muscles can increase the strength of inspiration and expiration. This type of breathing is also known as forceful breathing and can be found in pregnant women.

7. Pneumotaxic centre is located in ________
a) pons
b) cerebrum
c) medulla
d) cerebellum
Answer: a
Clarification: The Pneumotaxic centre is located on pons. It is called switch off point of inspiration. Neural signal from this centre can reduce the duration of inspiration and thereby alter the respiratory rate.

8. Which does not occur on normal inspiration?
a) Contraction in diaphragm
b) Contraction in external intercoastal muscle
c) Contraction in internal intercoastal muscle
d) Sternum moves upward
Answer: c
Clarification: At the time of inspiration diaphgram and external intercoastal muscle contracts leading to increase in thoracic volume. Also, ribs move outward and sternum moves upward.

9. Dead space air is _______
a) 150 CC
b) 350 CC
c) 500 CC
d) 1500 CC
Answer: a
Clarification: Dead space air is 150 CC. Dead space air represents the volume of air that does not participate in the gaseous exchange and remains in the lungs. It can’t be expired or inspired or altered.

10. The signal for voluntary muscle for forced breathing starts in ______
a) medulla
b) cerebrum
c) pons
d) cerebellum
Answer: b
Clarification: The signal for voluntary muscle for forced breathing starts in cerebrum. Cerebrum is the control center of all the voluntary actions of the body. In forceful inspiration or expiration, signals are generated through this.

To practice Biology Quiz for NEET Exam,

Biology Written Test Questions for AIIMS Exam on “Urine Formation – 2”.

1. What is the full form of JGA?
a) Juxtaglomerular apparatus
b) Juxta glomerulus aperture
c) Juxta glial apparatus
d) Juxta glial aperture
Answer: a
Clarification: JGA stands for Juxtaglomerular apparatus. The kidneys have built-in mechanisms for the regulation of glomerular filtration rate. One such efficient mechanism is carried out by the juxtaglomerular apparatus.

2. JGA is formed by the cellular modifications of which of the following?
a) PCT
b) DCT
c) Convoluted tubule
d) Renal tubule
Answer: b
Clarification: Juxtaglomerular apparatus is a special sensitive region formed by the cellular modifications in the distal convoluted tubule and the afferent arteriole at the location of their contact.

3. A fall in the GFR activates which of the following cells?
a) PCT cells
b) Podocytes
c) DCT epithelium
d) JG cells
Answer: d
Clarification: A fall in the GFR can activate the JG cells to release renin which can stimulate the glomerular blood flow and thereby the GFR back to normal.

4. What is the GFR of a healthy individual?
a) 150 litres per day
b) 180 litres per day
c) 200 litres per day
d) 80 litres per day
Answer: b
Clarification: GFR in a healthy individual is approximately about 125 ml per minute, i.e., 180 litres per day. Although, the amount of urine secreted by a healthy individual differs significantly and is only about 1.5 litre per day.

5. Nearly 75% of the filtrate is reabsorbed by the renal tubules.
a) True
b) False
Answer: b
Clarification: Nearly 99 per cent of the filtrate that passes through our renal tubules every minute is being reabsorbed by our blood capillaries and the renal tubules themselves. Approximately 180 litres of filtrate is formed per day but only 1.5 litres of urine is released. Therefore, a huge amount of filtrate is being reabsorbed every minute.

6. What is reabsorption?
a) Absorption of the filtrate by the renal tubules
b) Secretion of nutrients by the filtrate
c) Absorption of retentate by the renal tubules
d) Absorption of proteins and carbohydrates only
Answer: a
Clarification: The absorption of the filtrate by the renal tubules is termed as reabsorption. The tubular epithelial cells in different segments of the nephron perform this either by active or passive mechanisms.

7. Which of the following substances are not reabsorbed actively by the nephrons?
a) Glucose
b) Amino acids
c) Sodium ions
d) Nitrogenous wastes
Answer: d
Clarification: Substances like glucose, amino acids, sodium ions, etc., in the filtrate, are reabsorbed actively whereas the nitrogenous wastes are absorbed by passive transport.

8. How is water reabsorbed in the initial segments of the nephrons?
a) By the active transport
b) By the passive transport
c) Water is not reabsorbed
d) Sometimes by active transport and sometimes by passive transport
Answer: b
Clarification: Reabsorption of water occurs passively in the initial segments of the nephron. During urine formation, the tubular cells secrete some substances into the filtrate to enhance the reabsorption process.

9. Which of the following substances are not secreted by the tubular cells?
a) H⁺ ions
b) K⁺ ions
c) Ammonia
d) Glucose
Answer: d
Clarification: During urine formation, the tubular cells secrete substances like H⁺, K⁺ and ammonia into the filtrate in the proximal convoluted tubule and the distal convoluted tubule.

10. What is the significance of the tubular secretion?
a) To maintain the hypotonic condition with the plasma
b) To maintain the hypertonic condition with the plasma
c) To maintain the ionic balance
d) To maintain the air pressure
Answer: c
Clarification: Tubular secretion is an important step of urine formation in our kidneys. Tubular secretion helps in the maintenance of the ionic balance of various electrolytes and ions that are present in our body fluids.

11. By which protein is the blood colloidal osmotic pressure maintained?
a) Albumin
b) Globulin
c) Haemoglobin
d) Myoglobin
Answer: a
Clarification: The blood colloidal osmotic pressure or the BCOP of the glomerulus is maintained by the protein albumin. It resists the filtration of fluid from the capillaries.

12. Net filtration pressure is equal to the glomerular hydrostatic pressure.
a) True
b) False
Answer: b
Clarification: Net filtration pressure of the glomerulus is equal to:
Glomerular hydrostatic pressure – (Blood colloidal pressure + Capsular hydrostatic pressure)
It comes out equal to 10-15 mm Hg.

13. What does CHP stand for?
a) Capsular hydrostatic pressure
b) Capsid hydrated protein
c) Capsomere hydrated protein
d) Capsule hydrolysed protein
Answer: a
Clarification: CHP stands for Capsular hydrostatic pressure. It is the pressure caused by the filtrate or the fluid that reaches into Bowman’s capsule which resists filtration.

14. What is the condition of no urine formation called?
a) Oliguria
b) Polyuria
c) Diuresis
d) Anuria
Answer: d
Clarification: The condition of no urine formation is known as anuria. The condition of less urine formation is known as oliguria while excessive urine formation is known as polyuria.

15. What does CHP consist of?
a) Interstitial and artery pressure
b) Renal vein and artery pressure
c) Juxta medullary pressure and the arteriole pressure
d) Interstitial pressure and renal pressure
Answer: d
Clarification: CHP or Capsular hydrostatic pressure consists of Interstitial pressure and renal pressure. Both of these pressures act opposite to the glomerular hydrostatic pressure.

To practice Biology Written Test Questions for AIIMS Exam,

Biology Question Papers for NEET Exam on “Neuron-2”.

1. At resting membrane potential, the axonal membrane is impermeable to which ions?
a) Calcium ions
b) Sodium ions
c) Potassium ions
d) Chlorine ions
Answer: b
Clarification: The axonal membrane of the neuron or nerve cell is semi-permeable in nature. At resting membrane potential, the membrane is permeable to potassium ions but nearly impermeable to sodium ions.

2. Which of the following is not true regarding resting potential?
a) There is a potential difference across the plasma membrane
b) The potential difference is maintained by the Na-K pump
c) The outer surface of the membrane is negatively charged
d) The axonal membrane is polarized
Answer: c
Clarification: The axonal membrane is positively charged on the outer surface and negatively charged on the inner surface. This makes the membrane polarized. The potential difference is maintained by the Na-K pump.

3. Which of these does not take place when a stimulus is applied to a polarized axonal membrane?
a) It becomes permeable to sodium ions
b) The membrane is depolarized
c) There is a slow influx of sodium ions
d) Outer surface of the membrane becomes negatively charged
Answer: c
Clarification: When a stimulus is applied to a polarized axonal membrane, the polarity of the membrane is reversed. It becomes permeable to sodium ions and leads to its rapid influx. Outer surface of the membrane becomes negatively charged.

4. What is a nerve impulse also known as?
a) Action potential
b) Graded potential
c) Resting potential
d) Membrane potential
Answer: a
Clarification: A nerve impulse is also known as an action potential. It changes the resting membrane potential as it reverses the polarity of the axonal membrane. It becomes permeable to sodium ions and leads to its rapid influx.

5. How is the resting potential restored after a nerve impulse?
a) Potassium ions diffuse inside the membrane
b) Potassium ions diffuse outside the membrane
c) The membrane becomes impermeable to potassium ions
d) There is no movement of potassium ions
Answer: b
Clarification: After a nerve impulse, the permeability of the membrane to sodium ions reduces and increases for potassium ions. Potassium ions diffuse outside the membrane and hence restore the resting potential.

6. Nerve impulses are transmitted from one neuron to another via which of these?
a) Schwan cells
b) Nissl’s granules
c) Synapses
d) Myelin sheath
Answer: c
Clarification: Synapses are the gaps or junctions between two adjacent neurons via which nerve impulses are transmitted. This occurs by the release of chemical compounds known as neurotransmitters.

7. Which of these is not a component of the synapse?
a) Synaptic vesicles
b) Pre-synaptic membrane
c) Post-synaptic membrane
d) Synaptic cleft
Answer: a
Clarification: A synapse is present between two adjacent neurons. The pre-synaptic membrane of one neuron, the post-synaptic membrane of the next neuron and the synaptic cleft make up the synapse.

8. Which of the following statements is false regarding electrical synapses?
a) Membranes of pre and post-synaptic neurons are in very close proximity
b) Transmission is always faster than that across a chemical synapse
c) It is similar to impulse conduction along a single axon
d) Electrical synapses are common in our system
Answer: d
Clarification: In electrical synapses, the membranes of pre and post-synaptic neurons are in close proximity. It is similar to impulse conduction along a single axon and is always faster than transmission across a chemical synapse. It is rare in our system.

9. Which of these is false regarding synaptic clefts?
a) It lies between the membranes of pre and post-synaptic neurons
b) It is a fluid filled space
c) Electrical synapses have large synaptic clefts
d) It is a portion of the synapse
Answer: c
Clarification: Synaptic clefts are fluid filled spaces that lie between the membranes of pre and post-synaptic neurons. These together make up the synapse. Electrical synapses have very small synaptic clefts.

10. The outer surface of the axon has a positive charge at resting membrane potential. True or false?
a) True
b) False
Answer: a
Clarification: At resting membrane potential, the concentration of sodium ions is high outside the axonal membrane. Due to the sodium-potassium pump, the outer surface of the axon has a positive charge.

11. Which of these are involved in the transmission of nerve impulses?
a) Synaptic knob
b) Schwan cells
c) Nissl’s granules
d) Neurotransmitters
Answer: d
Clarification: Neurotransmitters are chemical compounds that help in the transmission of nerve impulses or action potentials. Nissl’s granules, Schwan cells and synaptic knobs do not participate in this process.

12. What happens to synaptic vesicles during an action potential?
a) They degrade their contents
b) They open up inside the synaptic knob
c) They move towards and fuse with the plasma membrane
d) They are released into the synapse
Answer: c
Clarification: During an action potential, the synaptic vesicles move towards the membrane of the neuron and fuse with the plasma membrane. This results in the release of neurotransmitters in the synaptic cleft.

13. Which of these structures are present on the post-synaptic membrane?
a) Synaptic knobs
b) Synaptic vesicles
c) Receptors
d) Schwan cells
Answer: c
Clarification: The post-synaptic membrane contains receptors. These are receptors for the neurotransmitters which are released from the pre-synaptic membrane at the terminal end of the adjacent neuron.

14. What happens when a neurotransmitter binds to a receptor on the post-synaptic membrane?
a) Opening of ion channels
b) Conformational changes in the neuron
c) Graded potential is transmitted across the neuron
d) It becomes impermeable to all ions
Answer: a
Clarification: When a neurotransmitter binds to a receptor on the post-synaptic membrane, it leads to the opening of ion channels. This allows the entry of ions which results in the generation of a new action potential.

15. Action potentials can be inhibitory. True or false?
a) True
b) False
Answer: a
Clarification: Action potentials or nerve impulses can be excitatory as well as inhibitory. They are conducted from neuron to neuron with the help of chemical compounds known as neurotransmitters.

To practice Biology Question Papers for NEET Exam,

Biology Multiple Choice Questions on “Living World – Nomenclature”.

1. Binomial nomenclature of Potato is _________
a) Solanum tuberosum
b) Ipomoea batatas
c) Phaseolus vulgaris
d) Daucus carota subsp. sativus
Answer: a
Clarification: Solanum tuberosum (Potato) (Species: Tuberosum; Genus: Solanum); Ipomoea batatas (Sweet potato) (Species: Batatas; Genus: Ipomoea); Phaseolus vulgaris (Beans) (Species: Vulgaris; Genus: Phaseolus); Daucus carota subsp. Sativus (Carrot) (Species: Carota; Genus: Daucus).

2. Panthera Pardus is the binomial nomenclature of leopard.
a) False
b) True
Answer: a
Clarification: Binomial nomenclature of any organism contains of two parts namely specific epithet and generic epithet. A generic epithet starts with a capital letter and a specific epithet should start with a small letter with both of them being separated by a gap. A binomial nomenclature should be written in italics. But here it is not written in italics and the starting letter in pardus is written in capitals. The binomial nomenclature of leopard is Panthera pardus.

3. The binomial nomenclature of peacock is _________
a) Pavo cristatus
b) Corvus corone
c) Haliaeetus leucocephalus
d) Barnardius zonarius
Answer: a
Clarification: Pavo cristatus (Peacock) (Species: Cristatus; Genus: Pavo); Corvus corone (Crow) (Species: Corone; Genus: Corvus); Haliaeetus leucocephalus (Bald eagle) (Species: Leucocephalus; Genus: Haliaeetus); Barnardius zonarius (Australian ring necked parrot) (Species: Zonarius; Genus: Barnardius).

4. Pick the incorrect statement.
a) Binomial nomenclature has two parts namely generic epithet and specific epithet and also some descriptive information along with them
b) Binomial nomenclature helps you to identify the relationship between animals
c) The rules for binomial nomenclature are set by IUCN
d) Binomial nomenclature is introduced in order to avoid ambiguity that is arises due to different names for a same animal in different languages
Answer: c
Clarification: The rules for binomial nomenclature for animals are set by International Union for Zoological Nomenclature (IUZN) and for plants by International Union for Botanical Nomenclature (IUBN). Binomial nomenclature has two parts namely generic epithet and specific epithet written in italics. Sometimes it might also contain description regarding the scientist. It helps you to track the evolutionary relationships of organisms.

5. Binomial nomenclature of Wheat is _________
a) Tritica aestivum
b) Musca domestica
c) Oryza sativa
d) Glycine max
Answer: a
Clarification: Tritica aestivum (Wheat) (Species: Aestivum; Genus: Tritica); Musca domestica (House fly) (Species: Domestica; Genus: Musca); Oryza sativa (Rice) (Species: Sativa; Genus: Oryza); Glycine max (Soybean) (Species: Max; Genus: Glycine). It’s necessary that binomial nomenclature is written in italics with generic epithet starting with capital letter and specific epithet written in small letter.

6. Which among the following is not a rule for writing binomial nomenclature?
a) The generic epithet should start with capital letter and specific epithet should start with small letter with a hyphen separating them
b) All the words in the binomial nomenclature should either be Latinized or should be derived from Latin
c) Binomial nomenclature may contain description about the organism
d) The first part of the binomial nomenclature contains the generic name and the second part contains the specific epithet
Answer: a
Clarification: The generic epithet should start with capital letter and specific epithet should start with small letter with a gap separating them. Nomenclature should be either derived from Latin or should be Latinized. It may also contain description about the organism like the name of the scientist who has done major works related to that organism.

7. Felis catus is the scientific name of __________
a) Cat
b) Lion
c) Dog
d) Cow
Answer: a
Clarification: Cat (Felis catus) (Species: Catus; Genus: Felis); Dog (Canis lupus familaris) (Species: Lupus; Genus: Canis); Cow (Bos taurus) (Species: Taurus; Genus: Bos); Lion (Panthera Leo) (Species: Leo; Genus: Panthera). Cat belongs to the family called Felicae which comprises of cat, lion, tiger and leopard.

8. Magnifera Indica belongs to the family ________
a) Felicae
b) Convolvulacae
c) Anacardiacae
d) Poacae
Answer: c
Clarification: Magnifera Indica belongs to the family Anacardiacae. It belongs to the species M.Indica and genus Magnifera. It comes under the class of Sapindales and order of Dicotyledonae. It comes under the phylum of Angiosperms of Plant kingdom.

9. Homo sapiens belong to the genus ________
a) Sapiens
b) Homo
c) Hominidae
d) Mammalia
Answer: b
Clarification: Since the first word in a binomial nomenclature refers to the generic epithet and the second word to generic epithet, here Homo becomes the genus and Sapiens will be the genus. Homo sapiens belong to the family Homindae and class Mammalia.

10. Canis auerus belongs to the family _______
a) Felicae
b) Canidae
c) Hominidae
d) Canis
Answer: b
Clarification: Canis auerus (Jackal) (Species: Auerus; Genus: Canis); Canis lupus (Wolf) (Species: Lupus; Genus: Canis); Canis lupus familaris (Dog) (Species: Lupus Familaris; Genus: Canis) and Vulpes vulpes (Fox) (Species: Vulpes; Genus: Vulpes) belong to the family Canidae.

Biology Multiple Choice Questions on “Flowering Plants Morphology – Stem”.

1. A stem is positively phototropic and most of the times negatively geotropic.
a) True
b) False
Answer: a
Clarification: A stem is positively phototropic and most of the times negatively geotropic. Roots are negatively phototropic and most of the times positively geotrophic. A stem can grow underground as well.

2. Which among the following is incorrect about stem?
a) It is initially greenish and turns woody gradually
b) A stem bears leaves, flowers, buds and fruits etc. and grows vertically erect
c) Both the shoot and stem refers to the same part of a plant
d) Aerial axis of a grown plant is called a stem
Answer: c
Clarification: Most of the times, tap roots become swollen to store. Radish adopts fusiform to store food. Napiform is found in turnip and the root is spherical in the top and tapers in the bottom. If the root is swollen in the middle and those that tapers on both the sides are called fusiform roots.

3. Which among the following statements is incorrect about stem?
a) The region of stem where buds arise is called a node
b) The region between two consecutive nodes is called inter-node
c) Stem helps in conduction of water and nutrients between root and shoot
d) Stem system includes fruits, flowers, buds and leaves etc
Answer: d
Clarification: The region of stem where buds arise is called a node. The region between two consecutive nodes is called inter-node. Stem helps in conduction of water and nutrients between root and shoot. Shoot system includes fruits, flowers, buds and leaves etc.

4. Which among the following is not correct about different modifications of stem?
a) Weak stems are aerial stems that are further classified into trailer, creeper and climber
b) Stems in rhizome, tuber and bulb grow under the ground
c) In some plants, stems are modified into thorns for defense
d) Stems in corn grow above the ground
Answer: d
Clarification: Weak stems are aerial stems that are further classified into trailer, creeper and climber. Stems in rhizome, tuber and bulb grow under the ground. In some plants, stems are modified into thorns for defense. Stems in corn grow under the ground.

5. Which among the following is not correct about aerial stems?
a) Aerial stems can be classified into week stems and strong stems
b) Trailers are classified into procumbent, decumbent and diffuse based on the way they trail on the ground
c) Tridax is an example of diffused stem
d) Climbers are those plants that climb on any neighboring plants using modified stem structure called tendrils
Answer: c
Clarification: Aerial stems can be classified into week stems and strong stems. Trailers are classified into procumbent, decumbent and diffuse based on the way they trail on the ground. Tridax is an example of decumbent stem. Climbers are those plants that climb on any neighboring plants using modified stem structure called tendrils.

6. Which among the following is incorrect about different modes of modifications in stems?
a) Tendrils are tender and spirally coiled structures that arise from the axillary buds help in climbing of plants
b) Stem thorns are woody and pointed structures that develop from apical buds and provides protection of plants
c) Phylloclades are similar to stem thorns in structure but phylloclades are modification of leaves carry photosynthesis and also reduce transpiration
d) In cladodes, only some part of stem is fleshy and green and they are capable of performing photosynthesis
Answer: b
Clarification: Tendrils are tender and spirally coiled structures that arise from the axillary buds help in climbing of plants. Stem thorns are woody and pointed structures that develop from axial buds and provides protection of plants. Phylloclades are similar to stem thorns in structure but phylloclades are modification of leaves carry photosynthesis and also reduce transpiration. In cladodes, only some part of stem is fleshy and green and they are capable of performing photosynthesis.

7. Which among the following statements is incorrect about creepers?
a) Runners are modified sub-aerial stem that run along the ground and roots develop at nodes
b) Suckers arise from the underground part of the stem and these roots are present in Mentha
c) Stolon arises from the base of the main stem and gives rise to a new plant when meets the soil
d) In pineapple, stem is modified into stolon
Answer: d
Clarification: Runners are modified sub-aerial stem that run along the ground and roots develop at nodes. Suckers arise from the underground part of the stem and these roots are present in Mentha. Stolon arises from the base of the main stem and gives rise to a new plant when meets the soil. In pineapple, stem is modified into suckers.

8. Which among the following is incorrect about rhizome?
a) Thick stems that grow horizontally under the soil are rhizomes
b) Nodes and internodes are present in this kind of roots and the adventitious roots arise from the node
c) Rhizomes are unaffected during unfavourable conditions
d) The edible part of ginger is a root
Answer: d
Clarification: Thick stems that grow horizontally under the soil are rhizomes. Nodes and internodes are present in this kind of stem and the adventitious roots arise from the node. Rhizomes are unaffected during unfavourable conditions. The edible part of ginger is the rhizome i.e. the underground stem.

9. The eyes in the potato are the nodes in the potato.
a) True
b) False
Answer: a
Clarification: In potato, the swollen tuber is the edible in stems. Tubers help in the storage of food. The eyes in the potato are the nodes in the potato. The distance between two eyes is called inter-node.

10. Which among the following is incorrect about bulb?
a) In bulb, stem is underground and condensed with fleshy leaves
b) Leaves are arranged in concentric fashion
c) In garlic, a single bulb is present
d) Scale leaves are present on the bulb
Answer: c
Clarification: In bulb, stem is underground and condensed with fleshy leaves. Leaves are arranged in concentric fashion. In onion, a single bulb is present whereas in garlic many bulbs combine to form a bigger bulb. Scale leaves are present on the bulb.