NEET Biology Cockroach MCQs Set 03

Answer: (a) Double, ventral and solid

Explanation:
1. The ventral nerve cord is a double, solid chain of ganglia.
2. A dorsal hollow nerve cord is a chordate character.

Teacher's Note:
1. Annelids and arthropods have a ventral nerve cord.
2. Cockroach has 9 ganglia.

Answer: (b) Pheromone

Explanation:
1. Females release pheromones to attract males.
2. Ecdysone and juvenile hormone control moulting.

Teacher's Note:
1. Pheromones are chemical messages.
2. They work between members of one species.

Answer: (c) Insects

Explanation:
1. The compound eye of insects is made of ommatidia.
2. Vertebrates have single-lens eyes.

Teacher's Note:
1. Compound eye = many ommatidia.
2. Cockroach has about 2000 per eye.

Answer: (c) Ommatidia

Explanation:
1. A compound eye is made up of many ommatidia.
2. The rhabdom is only a part of an ommatidium.

Teacher's Note:
1. Each ommatidium has a cornea and a rhabdom.
2. The combined image is mosaic.

Answer: (a) Mosaic

Explanation:
1. Each ommatidium forms a part of the image, giving mosaic vision.
2. The image is made of many small pieces.

Teacher's Note:
1. Mosaic vision is poor in detail.
2. It is good at detecting movement.

Answer: (b) Bright light

Explanation:
1. In bright light the pigment cells isolate each ommatidium and form the apposition image.
2. In dim light a superposition image is formed.

Teacher's Note:
1. Apposition: bright light.
2. Superposition: dim light.

Answer: (a) Centrolecithal

Explanation:
1. Centrolecithal eggs have a central yolk mass, as in insects.
2. Homolecithal eggs have evenly distributed yolk.

Teacher's Note:
1. Cockroach eggs are centrolecithal.
2. Cleavage is superficial.

Answer: (d) Collaterial gland

Explanation:
1. The collaterial glands secrete the hard case, the ootheca, around the eggs.
2. The phallic and conglobate glands are male glands.

Teacher's Note:
1. Collaterial glands belong to females.
2. Ootheca protects the eggs.

Answer: (c) 16

Explanation:
1. One ootheca generally contains about 14 to 16 eggs.
2. The usual textbook value is 16.

Teacher's Note:
1. Eggs are arranged in two rows of eight.
2. A female produces 9 to 10 oothecae.

Answer: (b) Centrolecithal

Explanation:
1. Insect eggs have a central yolk and are centrolecithal.
2. Telolecithal eggs have yolk at one pole.

Teacher's Note:
1. Centrolecithal gives superficial cleavage.
2. Isolecithal has little evenly spread yolk.

Answer: (d) Cockroach

Explanation:
1. Male and female cockroaches differ in anal styles, wings and sterna.
2. Hydra, earthworm and sponges are hermaphrodite or monoecious.

Teacher's Note:
1. Cockroach is unisexual.
2. Earthworm is hermaphrodite.

Answer: (c) Male cockroach

Explanation:
1. The conglobate (left phallomere) gland is a male accessory gland.
2. It is absent in females.

Teacher's Note:
1. Male accessory glands: utricular, phallic and conglobate.
2. Female: collaterial glands.

Answer: (c) 8

Explanation:
1. Each ovary contains eight ovarioles.
2. So there are 16 in total.

Teacher's Note:
1. 8 per ovary, 16 in all.
2. The ovarioles lie in the 2nd to 6th segments.

Answer: (b) Formation of the ootheca

Explanation:
1. Collaterial glands secrete the material that forms the ootheca.
2. They are accessory glands of the female.

Teacher's Note:
1. Genital pouch holds the ootheca for some time.
2. Glands open into the genital chamber.

Answer: (b) Gradual metamorphosis

Explanation:
1. The nymph looks like the adult and becomes adult through moults, so metamorphosis is gradual.
2. There is no pupal stage.

Teacher's Note:
1. Hemimetabolous or paurometabolous.
2. Butterflies show complete metamorphosis.

Answer: (c) Nymph

Explanation:
1. The young cockroach that hatches from the egg is a nymph.
2. Tadpole is the larva of frog.

Teacher's Note:
1. Nymph resembles the adult.
2. Naiad is the aquatic nymph of some insects.

Answer: (b) 3 to 3.5 years approximately

Explanation:
1. The average life span is about three to three and a half years.
2. It depends on temperature and food.

Teacher's Note:
1. Roughly three years.
2. Nymph stage lasts 5 to 6 months.

Answer: (a) Hydra

Explanation:
1. Hydra is a cnidarian and does not have a rigid exoskeleton, so it does not moult.
2. Arthropods shed their exoskeleton as they grow.

Teacher's Note:
1. Moulting is a feature of arthropods.
2. It is called ecdysis.

Answer: (c) Paurometaboly

Explanation:
1. In paurometaboly the young resemble the adult and grow through moults.
2. Ametaboly means no metamorphosis and holometaboly means complete.

Teacher's Note:
1. Paurometaboly is gradual metamorphosis.
2. Egg, nymph, adult.

Answer: (d) Ventral nerve cord

Explanation:
1. Both annelids and arthropods have a solid ventral nerve cord.
2. Cockroach is unisexual, moults and excretes through Malpighian tubules.

Teacher's Note:
1. Ventral nerve cord is a common protostome feature.
2. Earthworm does not moult.

Answer: (d) Jellyfish

Explanation:
1. Jellyfish are soft-bodied cnidarians without hard skeleton.
2. Insects have an exoskeleton.

Teacher's Note:
1. Insects have a chitinous exoskeleton.
2. Jellyfish use a hydrostatic skeleton.

Answer: (a) Nocturnal and omnivorous

Explanation:
1. Cockroaches hide during the day and feed at night.
2. They eat almost anything.

Teacher's Note:
1. Nocturnal = active at night.
2. They avoid light.

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Explanation:
1. Both are true because the circulation is open and the blood does not carry oxygen.
2. The first is not caused by the second, so R is not the explanation.

Teacher's Note:
1. Open circulation has sinuses, not capillaries.
2. These are two separate facts.