Question

 Which of the following characteristic is incorrect with respect to cockroach? [NEET 2021]

(a) A ring of gastric caeca is present at the junction of midgut and hindgut

(b) Hypopharynx lies within the cavity enclosed by the mouth parts

(c) In females, $7^{\text {th }}-9^{\text {th }}$ sterna together form a genital pouch

(d) $10^{\text {th }}$ abdominal segment in both sexes, bears a pair of anal cerci

Answer/Explanation

Ans. (a)

In cockroach a ring of 6-8 blind tubules called hepatic or gastric caeca is present at the junction of foregut and midgut which secrete digestive juice to facilitate digestion.
Rest statements are correct.

Question

 Following are the statements about prostomium of earthworm. [NEET 2021]

I. It serves as a covering for mouth.

II. It helps to open cracks in the soil into which it can crawl.

III. It is one of the sensory structures.

IV. It is the first body segment.

Choose the correct answer from the options given below

(a) I, II and III are correct

(b) I, II and IV are correct

(c) I, II, III and IV are correct

(d) II and III are correct

Answer/Explanation

Ans. (a)
Statements I, II and III are correct.
Earthworms have cylindrical body.
Anterior end consists of the mouth and the prostomium, a lobe which serves as a covering for the mouth and as a wedge to force open cracks in the soil. The prostomium is sensory in function.
Statement IV is incorrect and can be corrected as : The first body segment is called the peristomium.

Question

 In cockroach, identify the parts of the foregut in correct sequence. [NEET (Oct.) 2020]

(a) Mouth $\rightarrow$ Oesophagus $\rightarrow$ Pharynx $\rightarrow$ Crop $\rightarrow$ Gizzard

(b) Mouth $\rightarrow$ Crop $\rightarrow$ Pharyn $x \rightarrow$ Oesophagus $\rightarrow$ Gizzard

(c) Mouth $\rightarrow$ Gizzard $\rightarrow$ Crop $\rightarrow$ Pharyn $x \rightarrow$ Oesophagus

(d) Mouth $\rightarrow$ Pharyn $x \rightarrow$ Oesophagus $\rightarrow$ Crop $\rightarrow$ Gizzard

Answer/Explanation

Ans. (d)

In cockroach, the parts of the foregut in correct sequence are Mouth $\rightarrow$ Pharyn $x \rightarrow$ Oesophagus $\rightarrow$ Crop $\rightarrow$ Gizzard
The alimentary canal in cockroach has three regions, i.e. foregut, midgut and hindgut. The foregut comprises of the mouth, which opens into a short tubular pharynx, leading to a narrow tubular passage called oesophagus. This in turn opens into a sac-like structure called crop used for storing food. The crop is followed by gizzard or proventriculus which helps in grinding the food particles. 

Question

Match the following columns with reference to cockroach and select the correct option from the codes given belows. [NEET (Oct.) 2020]

   Codes
     A B C D
(a) 3 1 4 2

(b) 4 3 5 2

(c) 1 4 3 2

(d) 2 3 1 4

Answer/Explanation

Ans. (a)

The option (a) is the correct match with reference to cockroach which is as follows Grinding of the food particles is done by proventriculus or gizzard. Hepatic caeca is a ring of 6-8 blind tubules present at the junction of foregut and midgut. It secretes digestive juice. There are 10 pairs of small holes called spiracles present on the lateral side of the body which are part of respiratory system.
Anal cerci is a pair of jointed filamentous structure in both sexes in their 10th segment.

Question

 If the head of cockroach is removed, it may live for few days because [NEET (Sep.) 2020]

(a) the cockroach does not have nervous system

(b) the head holds a small proportion of a nervous system, while the rest is situated along the ventral part of its body

(c) the head holds a 1/3rd of a nervous system, while the rest is situated along the dorsal part of its body.

(d) the supra-oesophageal ganglia of the cockroach are situated in ventral part of abdomen

Answer/Explanation

Ans. (b)

Option (b) is correct because the nervous system of cockroach consists of a series of fused segmentally arranged ganglia joined by paired longitudinal connectives on the ventral side. Three ganglia, i.e. in the throax and six in the abdomen. In this way cockroach nervous system is spread throughout the body. The head holds a bit of a nervous system, while the rest is situated along the ventral (belly side) part of its body. Therefore if the head region of a cockroach is removed it may live for few days.

Question

Which of the following statements is incorrect? [NEET (Odisha) 2019]

(a) Cockroaches exhibit mosaic vision with less sensitivity and more resolution

(b) A mushroom-shaped gland is present in the 6-7th abdominal segments of male cockroach

(c) A pair of spermatheca is present in the 6 th segment of female cockroach

(d) Female cockroach possesses sixteen ovarioles in the ovaries

Answer/Explanation

Ans. (a)

Statement (a) is incorrect because cockroach vision is very sensitive but provides less resolution. Such vision is called mosaic vision. It has compound eye and each eye contains about 2000 ommatidia.

Question

 Select the correct sequence of organs in the alimentary canal of cockroach starting from mouth [NEET (National) 2019]

(a) Pharyn $x \rightarrow$ Desophagus $\rightarrow$ Gizzard $\rightarrow$ Crop $\rightarrow$ lleum $\rightarrow$ Colon $\rightarrow$ Rectum

(b) Pharyn $x \rightarrow$ Desophagus $\rightarrow$ Gizzard $\rightarrow$ lleum $\rightarrow$ Crop $\rightarrow$ Colon $\rightarrow$ Rectum

(c) Pharyn $x \rightarrow$ Desophagus $\rightarrow$ lleum $\rightarrow$ Crop $\rightarrow$ Gizzard $\rightarrow$ Colo $\rightarrow$ Rectum

(d) Pharyn $x \rightarrow$ Desophagus $\rightarrow$ Crop $\rightarrow$ Gizzard $\rightarrow$ lleum $\rightarrow$ Colon $\rightarrow$ Rectum

Answer/Explanation

Ans. (d)

The correct sequence of organs in the alimentary canal of cockroach starting from mouth is
Pharyn $x \rightarrow$ Oesophagus $\rightarrow$ Crop $\rightarrow$ Gizzard $\rightarrow$ lleum $\rightarrow$ Colon $\rightarrow$ Rectum.
Both crop and gizzard are the structures of foregut. The former serves as the food reservoir while the latter helps to masticate the food due to the presence of six chitinous teeth in it.

Question

Select the correct route for the passage of sperms in male frogs. [NEET 2017]
(a) Testes $\rightarrow$ Bidder’s canal $\rightarrow$ Kidney $\rightarrow$ Vasa efferentia $\rightarrow$ Urinogenital duct $\rightarrow$ Cloaca

(b) Testes $\rightarrow$ Vasa efferentia $\rightarrow$ Kidney $\rightarrow$ Seminal vesicle $\rightarrow$ Urinogential duct $\rightarrow$ Cloaca

(c) Testes $\rightarrow$ Vasa efferentia $\rightarrow$ Bidder’s canal $\rightarrow$ Ureter $\rightarrow$ Cloaca

(d) Testes $\rightarrow$ Vasa efferentia $\rightarrow$ Kidney $\rightarrow$ Bidder’s canal $\rightarrow$ Urinogenital duct $\rightarrow$ Cloaca

Answer/Explanation

Ans. (d)

In male frogs, germinal epithelium of seminiferous tubules produce sperms, which are transferred to kidney via vasa efferentia, from the kidney, these enter into Bidder’s canal from where, the sperms are carried to the transverse collecting tubules, longitudinal collecting tubule and then to urinogenital duct. The later carries the sperms to seminal vesical. where, they are stored temporarily. From here, sperms are carried to cloaca and then these shed into water.

Question

 Frog’s heart when taken out of the body continues to beat for sometime.
Select the best option from the following statements. [NEET 2017]
I. Frog is a poikilotherm.

II. Frog does not have any coronary circulation.

III. Heart is myogenic in nature.

IV. Heart is autoexcitable.

(a) Only III

(b) Only IV

(c) I and II

(d) III and IV

Answer/Explanation

Ans. (d)

Frog heart is myogenic and autoexcitable. In this conditions, contraction of the heart originates within the muscles itself. When muscles are contracting. They are releasing heat, which keeps the electrochemical reactions in muscles going so the muscles of heart keep contracting after the removal of heart from the body.

Question

Which of the following features is not present in Periplaneta americana? [NEET 2016, Phase I]

(a) Indeterminate and radial cleavage during embryonic development

(b) Exoskeleton composed of $\mathrm{N}$-acetylglucosamine

(c) Metamerically segmented body

(d) Schizocoelom as body cavity

Answer/Explanation

Ans. (a)

Cockroach has determinate cleavage during embryonic development and it develops into nymph, which is a fully developed cockroach except its size as it is much smaller than the adult one.

Question

 In male cockroaches, sperms are stored in which part of the reproductive system? [NEET 2016, Phase II]

(a) Seminal vesicles

(b) Mushroom glands

(c) Testes

(d) Vas deferens

Answer/Explanation

Ans. (a)

In male cockroaches, sperms are stored in the seminal vesicles of the reproductive system. The seminal vesicles are small sacs present on the ventral surface of the anterior of the ejaculatory duct.

Question

 The body cells in cockroach discharge their nitrogenous waste in the haemolymph mainly in the form of [CBSE AIPMT 2015]

(a) ammonia

(b) potassium urate

(c) urea

(d) calcium carbonate

Answer/Explanation

Ans. (b)

Insects including cockroach excrete nitrogenous waste in the form of soluble potassium urate which is liberated into the haemolymph and taken up by the cells lining the Malpighian tubules. The tubules facilitate the absorption of urate by stirring up the blood. In the cells of the tubule the potassium urate reacts with water and carbon dioxide (from respiration) to form potassium hydrogen carbonate and uric acid. The former is absorbed back into the blood, but the later is excreted.

Question

 What external changes are visible after the last moult of a cockroach nymph? [NEET 2013]

(a) Mandibles become harder

(b) Anal cerci develop

(c) Both fore wings and hind wings develop

(d) Labium develops

Answer/Explanation

Ans. (c)

In cockroach, development is pauro metabolous. The nymph grows by moulting about 13 times to reach the adult form. The next to last nymphal stage has wing pads but only adult. cockroaches have wings.
Anal cerci are a pair of jointed filamentous structures in $10^{\text {th }}$ segment of both sexes labium is a lower lip and a pair of mandibles are present in mouthparts of cockroach.

Question

 Select the correct statement from the ones given below with respect to Periplaneta americana. [CBSE AIPMT 2012]

(a) Nervous system located dorsally, consists of segmentally arranged ganglia joined by a pair of longitudinal connectives

(b) Males bear a pair of short thread-like anal styles

(c) There are 16 very long Malpighian tubules present at the junctions of midgut and hindgut

(d) Grinding of food is carried out only by the mouth parts

Answer/Explanation

Ans. (b)

In cockroach, the male and females can be identified easily with the presence or absence of one pair of anal styles in the posterior region. The anal styles are unjointed, thread-like structures present on the $9^{\text {th }}$ sternite of male.

Question

Which one of the following correctly describes the location of some body parts in the earthworm Pheretima? [CBSE AIPMT 2009]

(a) Two pairs of accessory glands in 16-18 segments

(b) Four pairs of spermathecae in 4-7 segments

(c) One pair of ovaries attached at intersegmental septum of 14 th and 15th segments

(d) Two pairs of testes in 10th and 11th segments

Answer/Explanation

Ans. (d)

In earthworm, two pairs of testes are found in 10th and 11th segments, accessory glands in 17th and 19th segments, four pairs of spermatheca from 6th-9th segment and one pair of ovaries in 13th segment.

Question

 If a piece of bone such as femur of frog is kept in dilute $\mathrm{HCl}$ for about a week. It will [CBSE AIPMT 2000]

(a) assume black colour

(b) shrink in size

(c) turn flexible

(d) crack into pieces

Answer/Explanation

Ans. (c)

When a bone is kept in dilute acid for a few days, the salts get dissolved, leaving only soft and flexible organic matrix (decalcification). If kept in $\mathrm{KOH}_{\text {, }}$ it remains unaffected, only the surrounding muscles and connective tissue get dissolved so that the bone now appears clean. If burned, the organic matter burns off producing smoke and the ash (mineral matter) is left behind.

Question

 In frog, the surface of attachment of tongue is [CBSE AIPMT 1997]

(a) sphenoid

(b) palatine

(c) pterygoid

(d) hyoid apparatus

Answer/Explanation

Ans. (d)

Main part of hyoid apparatus is a broad, flat and squarish plate, also called basilingual plate, because it provides attachment and support to the tongue.

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