NEET-PG 2017 - Physiology Practice Questions

Q: Which protein is responsible for the effect shown in RBC marked as $X$ ?

Band 3 protein. ***Band 3 protein*** - The image indicates that **X** facilitates the exchange of **bicarbonate (HCO₃⁻)** out of the red blood cell and **chloride (Cl⁻)** into the red blood cell, a process known as the **chloride shift** or **Hamburger phenomenon**. - This specific transporter is the **Band 3 anion exchanger 1 (AE1)**, also known as **Band 3 protein**, which is crucial for maintaining electrical neutrality during CO₂ transport. - **Band 3 protein** is the most abundant membrane protein in RBCs and accounts for approximately **25% of RBC membrane protein**. *Spectrin* - Spectrin is a **cytoskeletal protein** that forms a structural network on the inner surface of the RBC membrane. - It provides **mechanical stability and flexibility** to RBCs but does not participate in anion exchange. - Defects in spectrin cause hereditary spherocytosis and elliptocytosis. *Glycophorin* - Glycophorins are **surface glycoproteins** that carry many of the carbohydrate groups on the RBC surface. - They play roles in **membrane stability and blood group antigens** (MN blood group system). - They do not function as anion exchangers or transporters for bicarbonate/chloride. *Ankyrin* - Ankyrin is an **anchoring protein** that links the cytoskeletal protein spectrin to Band 3 protein. - It provides **structural support** and maintains membrane integrity but does not transport ions. - Ankyrin deficiency can cause hereditary spherocytosis.

Q: Identify the modality of intercellular communication shown below.

Paracrine. ***Paracrine*** - The image shows a **signaling cell** releasing **signaling molecules** (red dots) into the extracellular space, which then act on a nearby **target cell**. This local signaling is characteristic of paracrine communication. - In **paracrine signaling**, the molecules travel short distances through the interstitial fluid to influence neighboring cells, without entering the bloodstream. *Autocrine* - In **autocrine signaling**, a cell releases signaling molecules that then act on **receptors on the same cell** that produced them. The image clearly depicts communication between two different cells. - The signaling molecules are shown moving from one cell (signaling cell) to another distinct cell (target cell), rather than acting back on the originating cell. *Synaptic* - **Synaptic signaling** involves specialized structures called **synapses** where neurons transmit signals using **neurotransmitters** across a synaptic cleft to a target cell (another neuron, muscle cell, or gland cell). The image does not show a neuronal structure or a synapse. - This type of communication is highly specific to the nervous system and involves electrical impulses followed by chemical transmission, which is not represented here. *Gap junction* - **Gap junction communication** involves direct passage of signaling molecules between adjacent cells through specialized protein channels called **gap junctions**. - The image depicts signaling molecules being released into the extracellular space and binding to receptors on the target cell, rather than passing directly between the cytoplasms of two cells.

Q: Which of the following area of visual cortex is related to color vision?

V8. ***V8*** - **V8** is a specific area within the human **visual cortex** that has been implicated in **color perception**. - Damage to this area can lead to **cerebral achromatopsia**, a condition where individuals lose the ability to perceive colors. *V1* - **V1**, also known as the **primary visual cortex**, processes basic visual information such as orientation, spatial frequency, and color. - While it processes color information, it is not considered the primary or most specialized area for **color vision** compared to V8. *V2* - **V2** receives input from V1 and is involved in processing more complex visual features, including **form, depth, and color**. - It plays a role in color processing but is less specialized for this function than V8. *V3* - **V3** is primarily involved in processing **dynamic form** and motion, with some contribution to complex visual features. - It is not extensively associated with **color perception** as its main function.

Q: Which wave is seen in the given EEG recording?

Delta waves. ***Delta waves*** - The highlighted EEG activity shows **large amplitude, low-frequency waves** (typically 0.5-4 Hz), which are characteristic of delta waves. - Delta waves are normally associated with **deep sleep** (NREM stage 3) or **pathological conditions** in awake adults, indicating significant brain dysfunction. *Alpha waves* - Alpha waves have a frequency range of **8-13 Hz** and typically appear when an individual is in a relaxed, awake state with eyes closed. - The waves in the image are much slower and higher in amplitude than typical alpha waves. *Beta waves* - Beta waves are characterized by a higher frequency range of **14-30 Hz** and are associated with active thinking, alertness, and concentration. - The observed activity is significantly slower and higher in amplitude than beta waves. *Epsilon wave* - The term "epsilon wave" is not a standard classification for EEG brain waves in the context of normal or common pathological activity, unlike alpha, beta, theta, and delta waves. - In cardiology, "epsilon wave" refers to a specific finding on an ECG in **Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)**, not an EEG.

Question 1

Which protein is responsible for the effect shown in RBC marked as $X$ ?

Accepted Answer

Band 3 protein

Answer

Spectrin

Answer

Glycophorin

Answer

Ankyrin

Question 2

Identify the modality of intercellular communication shown below.

Accepted Answer

Paracrine

Answer

Autocrine

Answer

Synaptic

Answer

Gap junction

Question 3

The following skeletal muscle recording shows presence of: (Recent NEET Pattern 2016-17)

Accepted Answer

A = Twitch, B = Summation, C = Incomplete tetanus, D = Complete tetanus

Answer

A = Summation, B = Twitch, C = Complete tetanus, D = Incomplete tetanus

Answer

A = Twitch, B = Incomplete tetanus, C = Summation, D = Complete tetanus

Answer

A = Incomplete tetanus, B = Complete tetanus, C = Twitch, D = Summation

Question 4

Which of the following area of visual cortex is related to color vision?

Accepted Answer

V8

Answer

V1

Answer

V2

Answer

V3

Question 5

Which wave is seen in the given EEG recording?

Accepted Answer

Delta waves

Answer

Alpha waves

Answer

Beta waves

Answer

Epsilon wave

NEET-PG 2017 — Physiology