Text Book Back Questions and Answers - Chapter 4 Organ and Organ Systems in Animals 11th Biology Zoology Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Organ and Organ Systems in Animals
Text Book Back Questions and Answers
Question 1.
The clitellum is a distinct part in the body of earthworm Lampito mauritii, it is found in
(a) Segments $13-14$
(b) Segments $14-17$
(c) Segments $12-13$
(d) Segments $14-16$
Answer:
(b) Segments $14-17$
Question 2.
Sexually, earthworms are
(a) Sexes are separate
(b) Hermaphroditic but not self-fertilizing
(c) Hermaphroditic and self-fertilizing
(d) Parthenogenic
Answer:
(b) Hermaphroditic but not self-fertilizing
Question 3.
To sustain themselves, earthworms must guide their way through the soil using their powerful muscles. They gather nutrients by ingesting organic matter and soil, absorbing what they need into their bodies. Say whether the statement is true or false: The two ends of the earthworm can equally ingest soil.
(a) True
(b) False
Answer:
(b) False

Question 4.
The head region of Cockroach pairs of and shaped eyes occur.
(a) One pair, sessile compound and kidney shaped
(b) Two pairs, stalked compound and round shaped
(c) Many pairs, sessile simple and kidney shaped
(d) Many pairs, stalked compound and kidney shaped
Answer:
(a) One pair, sessile compound and kidney shaped
Question 5.
The location and numbers of malpighian tubules in Periplaneta
(a) At the junction of midgut and hindgut, about 150.
(b) At the junction of foregut and midgut, about 150 .
(c) Surrounding gizzard, eight.
(d) At the junction of colon and rectum, eight.
Answer:
(a) At the junction of midgut and hindgut, about 150 .
Question 6.
The type of vision in Cockroach is
(a) Three dimensional
(b) Two dimensional
(c) Mosaic
(d) Cockroach do not have vision
Answer:
(c) Mosaic
Question 7.
How many abdominal segments are present in male and female cockroaches?
(a) 10,10
(b) 9,10
(c) 8,10
(d) 9,9
Answer:
(a) 10,10

Question 8.
Which of the following have an open circulatory system?
(a) Frog
(b) Earthworm
(c) Pigeon
(d) Cockroach
Answer:
(d) Cockroach
Question 9.
Buccopharyngeal respiration in frog
(a) is increased when nostrils are closed
(b) stops when there is pulmonary respiration
(c) is increased when it is catching fly
(d) stops when mouth is opened.
Answer:
(b) Stops when there is pulmonary respiration
Question 10.
Kidney of frog is
(a) Archinephros
(b) Pronephros
(c) Mesonephros
(d) Metanephros
Answer:
(c) Mesanephros
Question 11.
Presence of gills in the tadpole of frog indicates that
(a) fishes were amphibious in the past
(b) fishes evolved from frog-like ancestors
(c) frogs will have gills in future
(d) frogs evolved from gilled ancestor
Answer:
(d) frogs evolved from gilled ancestor

Question 12.
Choose the wrong statement among the following
(a) In earthworm, a pair of male genital pore is present.
(b) Setae help in locomotion of earthworms.
(c) Muscular layer in the body wall of earthworm is made up of circular muscles and longitudinal muscles.
(d) Typhlosole is part of the intestine of earthworm.
Answer:
(a) In earthworm, a pair of male genital pore is present.
Question 13.
Which of the following are the sense organs of Cockroach?
(a) Antennae, compound eyes, maxillary palps, anal cerci
(b) Antennae, compound eye, maxillary palps and tegmina
(c) Antennae, ommatidia, maxillary palps, stemumv and anal style
(d) Antennae, eyes, maxillary palps, tarsus of walking legs and coxa
Answer:
(c) Antennae, ommatidia, maxillary palps, sternumv and anal style
Question 14.
What characteristics are used to identify the earthworms?
Answer:
In gardens, earthworms can be traced by their fecal deposits known as worm castings on the soil surface. The earthworms can be identified using the following characteristics:
- Long and cylindrical narrow body.
- Bilateral symmetry
- It is light brown in colour with purple tinge at the anterior end.
- The division of body into many segments or metameres.
- The dorsal surface of the body is marked by a dark mid dorsal line.
- In mature worms, segments 14-17 may be found swollen with a glandular thickening of the skin called the clitellum.
Question 15.
What are earthworm casts?

Answer:
The undigested particles of food along with earth passed out through the anus of the earthworm are called worm casting.
Question 16.
How do earthworms breathe?
Answer:
In earthworms, respiration takes place through the body wall by the moist skin diffusion, oxygen diffuses through the skin into the blood while carbon dioxide from the blood diffuses out.
Question 17.
Why do you call cockroach a pest?
Answer:
Cockroaches destroy food and contaminates it with their offensive odour. They are carriers of a number of bacterial diseases. The cockroach allergen can cause asthma to sensitive people.
Question 18.
Comment on the functions of alary muscles?
Answer:
Alary muscles are the triangular muscles that are responsible for blood circulation in the cockroach. Each segment has one pair and a pumped anteriorly to sinuses again.
Question 19.
Name the visual units of the compound eyes of cockroach.
Answer:
Ommatidia
Question 20.
How does the male frog attracts the female for mating?
Answer:
Male frog has a pair of vocal sacs and a nuptial pad on the ventral side of the first digit of each forelimb. Vocal sacs assist in amplifying the croaking sound of frog. It makes a characteristic sound and attracts the female.

Question 21.
Write the types of respiration seen in frog.
Answer:
Frog respires on land and in the water by two different methods. In water, skin acts as aquatic respiratory organ (cutaneous respiration). Dissolved oxygen in the water gets exchanged through the skin by diffusion. On land, the buccal cavity, skin and lungs act as the respiratory organs. In buccal respiration on land, the mouth remains permanently closed while the nostrils remain open.
The floor of the buccal cavity is alternately raised and lowered, so air is drawn into and expelled out of the buccal cavity repeatedly through the open nostrils. Respiration by lungs is called pulmonary respiration. The lungs are a pair of elongated, pink coloured sac-like structures present in the upper part of the trunk region (thorax). Air enters through the nostrils into the buccal cavity and then to the lungs. During aestivation and hibernation gaseous exchange takes place through skin.
Question 22.
Differentiate between peristomium and prostoinium in earthworm.
Answer:
Peristomium:
The first segment of the body of earthworm is called peristomium.
Prostomium:
A small flap overhanging the mouth is called prostomium or upper lip.
Question 23.
Give the location of clitellum and spermathecal openings in Lampito mauritii.
Answer:
In mature earthworms, 14 - 17th segments are swollen with a glandular thickening of the skin called the clitellum. Permathecal openings are three pairs of small ventrolateral apertures lying intersegmentally between the grooves of the segment $6 / 7,7 / 8$ and $8 / 9$.
Question 24.
Differentiate between tergum and a sternum

Answer:

Tergum:
Tergum is the covering each segment of cockroach on the dorsal side.
Sternum:
The sternum is the covering of each segment of cockroach on the ventral side.
Question 25.
Head of cockroach is called hypognathous. Why?
Answer:
The mouth parts of cockroach are directed downwards. The head is small, triangular lies at right angle to the longitudinal body axis. Hence it is called hypognathous.
Question 26.
What are the components of blood in frog?
Answer:
The blood consists of plasma [60\%] and blood cells [40\%], red blood cells, white blood cells, and platelets. RBCs are loaded with red pigment, nucleated and oval in shape. Leucocytes are nucleated, and circular in shape.
Question 27.
Draw a neat labeled diagram of the digestive system of frog.
Answer:

Question 28.
Explain the reproductive system of frog.
Answer:
The male frog has a pair of testes which are attached to the kidney and the dorsal body wall by folds of peritonium called mesorchium. Vasa efferentia arise from each testis. They enter the kidneys on both side and open into the bladder canal. Finally, it communicates with the urinogenital duct that comes
out of kidneys and opens into the cloaca (Fig. 1).

Female reproductive system (Fig. 2) consists of paired ovaries, attached to the kidneys, and dorsal body wall by folds of peritoneum called mesovarium. There is a pair of coiled oviducts lying on the sides of the kidney. Each oviduct opens into the body-cavity at the anterior end by a funnel like opening called ostia. Unlike the male frog, the female frog has separate genital ducts distinct from ureters. Posteriorly the oviducts dilated to form ovisacs before they open into cloaca. Ovisacs store the eggs temporarily before they are sent out through the cloaca.
In-Text Questions Solved
Question 1.
How do the earthworms sense activity in their habitat without eyes, ears or a nose?
Answer:
The earthworm's receptors are stimulated by a group of slender columnar cells connected with nerves. The Photoreceptors (sense of light) are found on the dorsal surface of the body. Gustatory (sense of taste) and olfactory receptors (sense of smell) are found in the buccal cavity. Tactile receptors (sense of touch), chemoreceptors (detect chemical changes) and thermoreceptors (changes in temperature) are present in the prostomium and the body wall.
Question 2.
Respiratory system of cockroach is formed of spiracles and tracheal interconnections. Why is it said to be more efficient than that of earthworm? Why inspiration of cockroach is said to be a passive process while it is an active process in man?
Answer:

The respiratory system of cockroach is well developed compared with other terrestrial insects. Branched tubes known as trachea open through 10 pairs of small holes called spiracles or stigmata
Question 3.
Arthropod eyes are called compound eyes because they are made up of repeating units, the ommatidia, each of which functions as a separate visual receptor. What is the difference between compound eyes and simple eyes? Why is mosaic vision with less resolution seen in cockroaches?
Answer:
$f$ an eye is made of many eyes, it is a compound eye. It has many visual receptors unlike a simple eye which has only one visual receptor. The photoreceptors of the cockroach consists of a pair of compound eyes at the dorsal surface of the head. Each eye is formed of about 2000 simple eyes called the ommatidia (singular: ommatidium), through which the cockroach can receive several images of an object. This kind of vision is known as mosaic vision with more sensitivity but less resolution.
Question 4.
Why three chambered heart of frog is not as efficient has the four chambered heart of birds and mammals?
Answer:
A 4-chambered heart can pump blood more powerfully and efficiently. This helps in better oxygenation of the blood, better circulation and better purification of the blood.
Entrance Examination Questions Solved
Question 1.

The body cells in cockroach discharge their nitrogenous waste in the haemolymph mainly in the form of
(a) Ammonia
(b) Potassium urate
(c) Urea
Answer:
(b) Potassium urate
Question 2.
Frog's heart when taken out of the body continues to beat for sometime. Select the best option from the following statements.
(a) Frog is a poikilotherm.
(b) Frog does not have any coronary circulation.
(c) Heart is "myogenic" in nature.
(d) Heart is autoexcitable Options
Answer:
(d) Heart is autoexcitable Options