Tag: biology

Questions Related to biology

Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction.

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Calcium

  2. Magneisum

  3. Sodium

  4. Potassium

Show answer
Correct Option: A
Explanation:

Calcium is the ion released into the sarcoplasma from sarcoplasmic reticulum during the polarisation.  Ca++ attaches to the Troponin-C. This brings a confirmational change in the tropomyosin. As a result unmasking of active sites on actin for myosin takes place. Cross bridges are formed between actin and myosin. This results in muscle contraction.

Magnesium is used in phosphorylation reactions involving ATP.
Sodium and potassium help in maintaining the membrane potential.
So the correct option is A.

Calcium ions bring about muscle contraction through

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Activation of myosin ATP-ase

  2. Exposing active sites of actin filaments

  3. Mobilisation of food reserve

  4. Both A and B

Show answer
Correct Option: A
Explanation:

  • The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin. 
  • ATP can then attach to myosin, which allows the cross-bridge cycle to start again; further muscle contraction can occur. 
  • Cardiac myosin activators stimulate myosin ATPase, thereby increasing force generation. Hence, Calcium ions bring about muscle contraction
  • through Activation of myosin ATP-ase.
 So, the correct answer is 'Activation of myosin ATP-ase'.

Organ of Golgi is the sensing structure formed at the junction of

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Two nerves

  2. Two bones

  3. Nerve and muscle

  4. Muscle and tendon

Show answer
Correct Option: D
Explanation:
Organ of Golgi. also known as Golgi tendon organ is a kind of proprioreceptor that sense stimulus within the body. It receives information from the tendons and sense tension in muscles. These kind of receptors get activated when the muscles stretch or contract due to any activity. These receptor are made up of collagen strands and formed at the junction of muscle and tendon.
So, the correct answer is 'Muscle and tendon'.

During strenuous muscular activity, hydrogens removed from sugar molecules are accepted temporarily by .......... to form..........        

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. oxygen; water

  2. pyruvate; lactic acid

  3. myoglobin; carbaminohaemoglobin

  4. oxygen; carbon dioxide

Show answer
Correct Option: B
Explanation:

During the strenuous muscular activity, hydrogens removed from sugar molecules are accepted temporarily by pyruvate to form lactic acid.

So, the correct option is 'pyruvate; lactic acid'.

Upon stimulation of skeletal muscles, calcium is immediately made available for binding to troponin from

biology locomotion and movement locomotion in animals bones and movements muscle contraction types of muscles muscles

  1. Wood

  2. lymph

  3. sarcoplasmic reticulum

  4. bone

Show answer
Correct Option: C
Explanation:

Upon stimulation of skeletal muscles, calcium is immediately made available for binding to troponin from 'sarcoplasmic reticulum'.

Exoskeleton is mesodermal in

biology movement and locomotion in man locomotion in animals bones and movements muscle contraction

  1. Mammals

  2. Birds

  3. Fishes

  4. Fishes, crocodiles and chelones

Show answer
Correct Option: A
Explanation:
  • The protective or supporting structure covering the outside of the body of many animals is called the exoskeleton. 
  • The exoskeleton is mesodermal in mammals.
  • So, the correct answer is 'Mammals'

The term "innominate" is used for?

biology movement and locomotion in man locomotion in animals bones and movements muscle contraction

  1. A bone and an artery

  2. A bone and a vein

  3. A bone and a nerve

  4. A vein and a nerve

Show answer
Correct Option: A
Explanation:
The term innominate means unnamed or anonymous. It is often used to refer to certain anatomical structures that have a descriptive name rather than precise ones. In humans this termed is used to refer to the hip bone and brachiocephalic artery.
Hence, the correct answer is 'A bone and an artery'.

Animals can be distinguished in to chordates and non chordates depending on presence and absence of _________.

biology movement and locomotion in man locomotion in animals bones and movements muscle contraction

  1. Three germ layers

  2. Mesoderm

  3. Notochord

  4. Both B and C

Show answer
Correct Option: C
Explanation:

The animals having notochord further develop a skeleton as in vertebrates. Animals without notochord have no skeleton as in invertebrates.

An example of chitinous exoskeleton is

biology movement and locomotion in man locomotion in animals bones and movements muscle contraction

  1. Oriole

  2. Sea stars

  3. Clam

  4. Honeybee

  5. Earthworm

Show answer
Correct Option: D
Explanation:

  • A tough, semitransparent substance that is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects(honey bee). 
  • Chitin is also found in the cell walls of certain fungi and algae. Chemically, it is a nitrogenous polysaccharide (a carbohydrate). Hence, An example of a chitinous exoskeleton is Honeybee.
So, the correct answer is 'Honeybee'.

Endoskeleton of cell is

biology movement and locomotion in man locomotion in animals bones and movements muscle contraction

  1. Cell wall

  2. Endoplasmic reticulum

  3. Cytoplasm

  4. Mitochondria.

Show answer
Correct Option: B