FREE NEET Biology Practice MCQ Test: Structural Organisation In Animals Exercise 2 Questions Answers With Detailed Explanations [PDF]

Answer: (d)

It is a muscular tissue. Muscle fibres is not a connective tissue.

Answer: (a)

In Pheretima, next to stomach is the intestine. It is a long, wide and thin walled tube extending from 15th segment to the last. Second or middle part of the intestine lies between $27^{th}$ segment up to 23–25 segments in front of anus. This is characterised by the presence of a highly glandular and vascular longitudinal ridge, arising as a median in-growth of the dorsal aspect of the intestinal cavity. This is called the typhlosole. The typhlosole greatly increases the effective absorption area of the digested food in the intestine.

Answer: (b)

Answer: (c)

Answer: (c)

In cokroach, respiratory system consists of a network of trachea, that open through 10 pairs of small holes called spiracles present on the lateral side of the body.

Answer: (d)

A cell junction (or intercellular bridge) is a type of structure that exists within the tissue of some multicellular organisms, such as animals. Cell junctions consist of multiprotein complexes that provide contact between neighbouring cells or between a cell and the extracellular matrix. There are three major types of cell junctions: adherens junctions, desmosomes and hemidesmosomes (anchoring junctions); gap junctions (communicating junction); tight junctions (occluding junctions).

Answer: (d)

Answer: (d)

Answer: (a)

In wounds, germs are removed by WBCs accumulation at wound site by diapedesis. It is squeezing of leucocytes out from endothelium of capillaries to tight external agent.

Answer: (b)

Answer: (c)

Smooth muscles are called as involuntary muscles as action of these muscles is controlled by autonomic nervous system i.e., not under the control of animal's will. Iris of eyes consist of smooth involuntary muscles. Abdominal wall also have smooth muscles. Biceps of upper arm is made of skeletal muscles while heart wall consists of cardiac muscles.

Answer: (b)

Answer: (b)

In male cockroaches, 9 th sternum bears a pair of short, unjointed thread-like anal styles which are absent in females. Anal cerci and antennae are present in both male and female cockroaches.

Answer: (c)

Answer: (d)

Answer: (a)

Neurons are the basic structural and functional units of the nervous system. Neurons are least likely to be replaced by new cells as they have least regeneration power.

Answer: (d)

Most cells in animal tissues (with the exception of a few terminally differentiated cells such as skeletal muscle cells and blood cells) are in communication with their adjoining cells via gap junctions. At the place where gap junction is present, membranes of two adjacent cells are separated by a uniform narrow gap of about 2-4 nm. The gap is spanned by channel forming proteins called connexins, which allow inorganic ions and other small water soluble molecules to pass directly from cytoplasm of one cell to cytoplasm of other cell.

Answer: (a)

Answer: (d)

Answer: (c)