Tag: biology

• The forelimb is composed of the humerus, radius and ulna, carpals (wrist bones – 8 in number), metacarpals (palm bones – 5 in number) and phalanges (digits – 14 in number). Hence radius-ulna is bones of the forelimb.
  
• The olecranon process is the near end of the ulna and it forms the pointed portion of the elbow.
• Sigmoid notch is a large depression in the upper extremity of the ulna that fits the trochlea of the humerus (the bone directly above the ulna in the arm) as part of the elbow joint. It is formed by the olecranon and the coronoid process.
• Hence sigmoid notch of the olecranon process is found in radius-ulna.
• So, the correct answer is 'Radius-ulna'.

Trochanter is the bony prominences present toward the near end of the thighbone or femur. The trochanters are the points at which hip and thigh muscles attach. These trochanters usually serves as muscle attachment sites. So, the correct answer is 'Femur'. 

• We move our hands while walking is a natural motion wherein each arm swings with the motion opposite that of the leg.
• Moving arms in an opposing direction with respect to the lower limb reduces the angular momentum of the body which helps in balancing the rotational motion produced during walking.
• Hence we move our hands while walking for balancing.
• So, the correct answer is 'Balancing'.
  

Epiphyseal plate (hyaline cartilage) is formed between diaphysis and epiphysis. This contributes in bone elongation.

• The bones of the hand (forelimb) are humerus, radius and ulna, carpals (wrist bones – 8 in number), metacarpals (palm bones – 5 in number) and phalanges (digits – 14 in number).
• The olecranon is the near end of the ulna which forms the pointed portion of the elbow.
• Hence ulceranon process occurs in ulna.
• So, the correct answer is 'Ulna'.
  

• A pectoral girdle or shoulder girdle attach the bones of upper limb to the axial skeleton.
  
• Each pectoral girdle is formed of two halves. Each half of pectoral girdle consists of a scapula and clavicle. 
• Glenoid cavity is a shallow, pyriform articular surface, which is located on the lateral angle of the scapula. It articulates with the humerus to form the shoulder joint. Hence glenoid cavity is associated with scapula and humerus.
• So,the correct answer is 'Both A and B'.

Digital formula is a way of comparing animals by the number of phalanges that they have in each of their digits. It can be used to study phylogeny or to predict how an animal may use its hands and feet. An animal’s phalangeal formula is simply given as a series of numbers. Most land mammals including humans have a 2-3-3-3-3 formula in both the hands(or paws) and feet. Fore limb of frog is 0-2-2-3-3 and hind limb is 2-2-3-4-3.

So, the correct answer is ‘2-2-3-4-3’.

The humerus is the single bone of the upper arm region. It articulates with the radius and ulna bones of the forearm to form the elbow joint. Distally, the humerus becomes flattened. The much smaller lateral epicondyle of the humerus is found on the lateral side of the distal humerus.