Free Biodiversity and Variety of Life MCQs with Answers

941. Which phylum does not show tissue level of organization?

• A. Nematoda
• B. Coelenterata
• C. Porifera
• D. Echinodermata

Explanation: Phylum Porifera, which includes sponges, has no tissue level organization. Sponges are the simplest animals and are characterized by their lack of true tissues, organs, and body symmetry. Instead, they have a porous body with numerous openings called ostia, which allow water to flow through the sponge and filter out food particles.

942. What is false about the closed circulatory system?

• A. Blood pressure is high and regular
• B. Amount of blood is limited
• C. Blood circulates through arteries, veins, and capillaries
• D. Blood pressure is low and irregular

Explanation: In an open circulatory system, blood pressure is generally low and irregular, as the blood is not confined to vessels and instead flows freely through the body cavity. This can limit the efficiency of oxygen and nutrient delivery to the body's tissues, as well as the removal of waste products. In contrast, a closed circulatory system maintains a higher and more consistent blood pressure, which allows for more efficient delivery of oxygen and nutrients to the body's tissues.

943. Water vascular system is found in:

• A. Mollusca
• B. Annelida
• C. Arthropoda
• D. Echinodennata

Explanation: The most unique characteristics of echinoderms is that a water vascular system is present in their coelom. It is a complex system of tubes and spaces surrounding the mouth and passing into the arms and tube feet.

944. 1. Fertilization_. 2. Digestive system_.3. Excretion by_.Fill in the blanks for the organism given in the below figure:

• A. Internal, Blind end, rennet cells
• B. External, Tube-like, nephridia
• C. Internal, Saclike, flame cells
• D. External, Saclike, protonephridia

Explanation: Fertilisation is Internal Digestive system is saclike Excretion is performed by flame cells

945. Select from the following the total number of an organism that belongs to the phylum Arthropoda: Locust, Butterfly, Scorpion, Prawn, Crab, Lobster, Mosquitoes, Leech, Earthworm, Land snail, Wasp.

• A. 3
• B. 8
• C. 5
• D. 11

Explanation: Arthropods are variable structurally. Some are worm-like centipedes while the others are lying insects with the body divided into distinct regions, the head, thorax and abdomen. Hence, all given animals belong to phylum arthropoda except leech, land snails and earthworms.

946. Four chambered heart is present in:

• A. Frog
• B. Crocodiles
• C. Snake
• D. Turtle

Explanation: Crocodiles have a partially divided heart, which means they have a three-chambered heart. It's different from the four-chambered heart found in mammals, birds, and some reptiles.

947. Saliva in leech contains as anti-coagulant called:

• A. Hirudin
• B. Antihistamine
• C. Heparin
• D. Ptyalin

Explanation: The saliva of leeches contains hirudin, a potent anticoagulant that prevents blood clotting during feeding.

948. Kangaroo is a:

• A. Eutherian
• B. Bird
• C. Prototherian
• D. Metatherian

Explanation: Metatheria is a subclass of mammals that includes marsupials. Unlike placental mammals (eutherians), marsupials give birth to relatively undeveloped young, which then continue to develop outside the womb, typically in a pouch. Examples include kangaroos and koalas.

949. The systems such as integumentary and nervous system developed from:

• A. Endoderm
• B. Ectoderm
• C. Mesoderm
• D. Mesoglea

Explanation: The systems such as integumentary and nervous develop from ectoderm.

950. The pores by which the water leaves the body of sponges are called:

• A. Ostia
• B. Anus
• C. Mouth
• D. Osculum

Explanation: The osculum is a large opening found on the top surface of a sponge (Porifera). It is the main exit through which water, along with waste particles and other substances, is expelled from the sponge after it has been filtered and processed by the internal cells.