Free Biodiversity and Variety of Life MCQs with Answers

1791. Phyllode is present in

• A. Asparagus
• B. Euphorbia
• C. Australian Acacia
• D. Opuntia

Explanation: (c) : In several species of Acacia found in the deserts of Australia the bipinnate lamina is absent. Instead petiole and part of the rachis become flattened into sickle­shaped structure for performing the function of food synthesis. Such a flattened petiole which carries out the functions of the lamina is called phyllode. Formation of phyllode is a mechanism to reduce transpiration because (i) it is vertically placed and (ii) has fewer stomata.

1792. The gynoecium consists of many free pistils in flowers of

• A. Aloe
• B. Tomato
• C. Papaver
• D. Michelia

Explanation: (d): Gynoecium is the female reproductive organ of a flower. It may be apocarpous (pistils separated) e.g., Michelia, or syncarpous (fused) e.g., tomato.

1793. Flowers are zygomorphic in

• A. Mustard
• B. Gulmohar
• C. Tomato
• D. Datura

Explanation: (b): Flowers of Gulmour have bilateral symmetry. So, they are called zygomorphic. Datura, mustard, and tomato have actinomorphic flowers.

1794. The ovary is half inferior in flowers of

• A. Peach
• B. Cucumber
• C. Cotton
• D. Guava

Explanation: (a): If the gynoecium is situated in the center and other parts of the flower are located on the rim of the thalamus almost at the same level, it is called perigynous. The ovary here is said to be half inferior, e.g., plum, rose, peach

1795. Which one of the following pairs is wrongly matched while the remaining three are correct?

• A. Penicillium - Conidia
• B. Water hyacinth - runner
• C. Bryophyllum - leaf buds
• D. Sunflower - bulbils

Explanation: The pair that is wrongly matched is "Sunflower - bulbils." The pairs "Penicillium - conidia," "Water hyacinth - runner," and "Bryophyllum - leaf buds" are correctly matched based on the reproductive modes or characteristic features of the plants.

1796. Which one of the following figures represents the placentation in Dianthus?

• A. Option-A
• B. Option-B
• C. Option-C
• D. Option-D

Explanation: (b): The figure given in option (b) represents the free central placentation. In free central placentation, the ovary is unilocular and ovules are borne on the axis in the center of the ovary and septa are absent. It is seen in Dianthus and Primrose.

1797. Whorled, simple leaves with reticulate venation are present in

• A. Calotropis
• B. Neem
• C. China rose
• D. Alstonia

Explanation: (d): In Alstonia, five or more leaves arise from each node, so it shows a whorled phyllotaxy. The leaves are leathery, sessile, simple elliptical or ovate or wedge-shaped at the base. It is used in traditional medicines.

1798. Sweet potato is homologous to

• A. Potato
• B. Colocasia
• C. Ginger
• D. Turnip

Explanation: Sweet potato is homologous to turnip as both are root vegetables i.e., both are root but modified for different functions. Sweet potato is a modified root for storage and vegetative propagation while turnip is modified stem for storage only.

1799. In unilocular ovary with a single ovule, the placentation is

• A. Marginal
• B. Basal
• C. Free central
• D. Axile

Explanation: (b): In the basal type of placentation the ovary is unilocular and ovules and generally reduced to one borne at the base of the ovary, e.g., Compositae

1800. Keel is characteristic of the flowers of

• A. Gulmohar
• B. Cassia
• C. Calotropis
• D. Bean

Explanation: (d): The flowers of Family Papilionaceae have butterfly-shaped corolla (papilionaceous corolla). The posterior or outermost petal is the largest and is called standard or vexillum, two lateral petals are similar and generally clawed, are called wings or alae and the two anterior petals called keel are fused enclosing stamens and carpels. This type of petal arrangement is found in beans, grams, peas, Indigofera, etc