Structural Organisation in Animals Test - 35

• Spinal cord and brain control all activities of our body. Spinal cord possesses nerves, which carry messages between the brain and the body.
•  The brain sends commands for the functioning of different organs of the body via nerves. 
• Therefore, they are made of nervous tissue. Hence, option B is correct.  

• Tendon is a tough fibrous connective tissue, which connects muscle to bone.
• Blood consists of a fluid or liquid matrix called plasma in which white blood cells, red blood cells and platelets are suspended. Blood flows throughout the body and transports gases, nutrients, digested food, hormones and waste materials to different parts of the body.
• Cartilage has widely spaced cells and interspersed in a matrix made of proteins and sugars. It covers the ends of bones at joints.
• The ligament is a fibrous connective tissue, which connects bone to another bone. 

Therefore, option A is correct.

Cyton is a cell body of the neuron containing a nucleus, cytoplasm.   
Synapse is a structure that allows a neuron to pass an electrical signal or chemical signal to another neuron. 
Axon is a long, thin, hair-like process arising from the cell body of the neuron. 
A neuron is the functional unit of nervous tissue. It contains cyton or cell body, long, thin hair like the process called axon and many short branches called dendrites. Therefore, option C is correct. 

The average length of muscle fibers is of a few centimeters. 
The average size of epithelial cells is of few microns. 
Nerve cells possess a cell body and one to many thin, fiber-like axons.

Contraction or relaxation of the urinary bladder is not under control of the conscious will. As and when urine is formed, it is stored in the urinary bladder and its muscles are stretched. These muscles are smooth muscles and they are involuntary and unstriated.

Hence the correct option is B.

• Areolar tissue is connective tissue.
• Areolar connective tissue holds organs in place and attaches epithelial tissue to other underlying tissues. It also serves as a reservoir of water and salts for surrounding tissues.
•  Almost all cells obtain their nutrients from and release their wastes into areolar connective tissue.

Hence, option C is correct. 

Nerve cells carry out different functions such as receiving the message from within or outside of the body, transferring the messages from body part to the brain, and carrying the signal from the brain to different parts of the body. Thus, nerve cell helps the brain in control and coordination of the body.
Therefore, option D is correct.