Tag: zoology

Questions Related to zoology

Cross bridges of sarcomere in skeletal muscle are made up of 

  1. Actin

  2. Myosin

  3. Troponin

  4. Tropomyosin


Correct Option: B
Explanation:
  • Active sites for myosin (Thick filament) are present on actin which are masked by troponin in resting state. when  Ca++ level increases it leads to the binding of calcium with a subunit of troponin on actin(thin) filaments and thereby remove the masking of active sites for myosin.
  • Utilizing the energy from ATP hydrolysis, the myosin head now binds to the exposed active sites on actin to form a cross bridge. thus myosin forms cross bridges.
  • This pulls the attached actin filaments towards the centre of ‘A’ band.
  •  The ‘Z’ line attached to these actins are also pulled inwards thereby causing a shortening of the sarcomere, i.e., contraction.
  • Hence cross bridges of sarcomere in skeletal muscle are made up of myosin.
  • So, the correct answer is 'Myosin'.

Biceps muscle is found on

  1. Radius

  2. Femur

  3. Ulna

  4. Scapula


Correct Option: A
Explanation:

Bicep muscles are present at front of our upper arm. It contains two tendons that help it to attach it from the bones of the shoulder and other one is attached to the radius bone of the elbow.

So the correct option is "Radius".
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State whether the following statements are true or false.
Intercalated discs make up striations in the skeletal muscle.

  1. True

  2. False


Correct Option: B
Explanation:

Intercalated discs support synchronized contraction of cardiac tissues. They occur at the Z line of the sarcomere and can be visualized easily when observing a longitudinal section of the tissue. Three types of cell junction make up an intercalated disc.

So, the option is 'False'.

Which muscles having functionally multinucleated conditions?

  1. Cardiac muscle

  2. Smooth muscle

  3. Voluntary muscle

  4. All of these


Correct Option: C
Explanation:

There are cardiac, skeletal and smooth muscle cells of which only skeletal or voluntary muscle cells are multinucleated. Such cells are syncytial. Skeletal muscle cells arise in the embryo as uninucleated entities. Later the cells fuse to give rise to the multinucleated muscle fibre.

So the correct answer should be option C "voluntary muscles".

Consider the following statements each with one or two blanks.
(i) Each half of pectoral girdle consists of a (A) and a (B) 
(ii) (C) is a condition of rapid spasms (wild contractions) in muscle due to low $Ca^{++}$ in body fluid.
(iii) Each organised skeletal muscle In our body is made of a number of (D) held together by a common collagenous connective tissue layer called (E) Which one of the following options correctly fills the blanks in any two of the statements ?

  1. (C) - Muscular dystrophy, (D) - fascia, (E) - fascicle

  2. (A) - clavicle, (B) - scapula, (C) - Tetany

  3. (A) - ilium, (B) - ischium, (D) - fascicles, (E) - fascia

  4. (C) - Myasthenia gravis, (D) - fascicles. (E) - fasda


Correct Option: B
Explanation:

Each half of pectoral and pelvic girdle consist of clavicle & scapula, tetany is a condition of rapid spasms in muscle due to low calcium ion in body fluid.

So, the correct option is '(A) - clavicle, (B) - scapula, (C) - Tetany'.

The posture and equilibrium is maintained by which part of the brain?

  1. Hypothalamus

  2. Medulla oblongata

  3. Cerebrum

  4. Cerebellum


Correct Option: D
Explanation:
A. The function of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland.
B. The medulla oblongata is a part of the brain and it is a center for respiration and circulation. Sensory and motor neurons from the forebrain and midbrain travel through the medulla.
C. The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action.
D. The cerebellum (back of brain) is located at the back of the head. Its function is to coordinate voluntary muscle movements and to maintain posture, balance, and equilibrium.
So, the correct answer is "Cerebellum".

Motor learning is related to .............

  1. Cerebellum

  2. Cerebrum

  3. Pons

  4. Medulla oblongata


Correct Option: A
Explanation:

The cerebellum is an area of the mind that assumes an imperative job in engine control. It might likewise be associated with some intellectual capacities, for example, consideration and dialect, and in controlling trepidation and joy reactions, however, its development related capacities are the most firmly settled.


So, the correct option is 'Cerebellum'.

Which of the following is not a structure in the hindbrain?

  1. Medulla oblongata

  2. Thalamus

  3. Cerebellum

  4. Pons


Correct Option: B
Explanation:

Hindbrain has 3 parts - (1) pons, (2) cerebellum, (3) medulla oblongata. Diencephalon is a small and posterior part of forebrain. It is covered by cerebrum. It consists of thalamus, hypothalamus, epithalamus and metathalamus.

Which part of the brain control the posture and balance of the body?

  1. Cerebrum

  2. Medulla

  3. Cerebellum

  4. Pons varoli


Correct Option: C
Explanation:

a) Cerebrum serves to receive sensory inputs, to bring about integration before commanding voluntary motor responses, to coordinate the activities of another part of the brain, and to carry out higher thought processes for learning, memory, language and speech. 

b) Medulla oblongata consists of reflex centres that control heartbeat, blood vessel diameter and rhythm of breathing as well as other vital functions. 
c) Cerebellum serves to coordinate the voluntary movements of skeletal muscles as well as posture, balance and equilibrium. The vestibulocerebellum receives sensory input from vestibular apparatus and visual area and the output is sent to vestibular nuclei in the brain stem, thereby controlling posture and equilibrium. 

d) Pons serves as a connector between spinal cord and brain and between different parts of the brain, it also controls breathing.

So, the correct answer is option C.

Reflexes for maintaining vital functions like blood pressure are located in

  1. Hindbrain

  2. Midbrain

  3. Forebrain

  4. Cerebrum


Correct Option: A
Explanation:

The hindbrain includes the cerebellum, the pons and the medulla oblongata, which function collectively to support vital bodily processes. The medulla is joined to the spinal cord and controls unconscious, essential body functions such as breathing, swallowing, blood circulation and muscle tone. Located above the medulla is the pons, which receives information from visual areas to control eye and body movements and also plays a role in controlling patterns of sleep and arousal. Information is relayed from the pons to the cerebellum to control the coordination of muscular movements and maintain equilibrium.