All Free Biology MCQs with Answers

1731. The biggest group of invertebrates is_________?

• A. Worms
• B. Insects
• C. Jelly fish
• D. None of these

Explanation: Insects are the largest group of invertebrates and are distinguished by jointed appendages, a segmented body and usually three body regions. Students may choose worms because they include many forms, but worms are not a single taxonomic group comparable in size to insects.

1732. The vascular plants are termed as____________?

• A. tracheophytes
• B. bryophytes
• C. pteridophytes
• D. all of these

Explanation: Tracheophytes are vascular plants because they possess xylem and phloem for transporting water, minerals, and organic nutrients. Students may choose pteridophytes because they are vascular plants, but pteridophytes are only one group within the broader tracheophytes.

1733. Outside the thallus of Marchantia there are special structures called__________?

• A. stem tuber
• B. rhizoids
• C. sporangium
• D. none of these

Explanation: Marchantia is a thalloid liverwort whose underside bears rhizoids that anchor the thallus and help absorb water. Sporangia are reproductive structures, not the hair-like anchoring structures found outside the thallus, so students may select them by confusing support with reproduction.

1734. Which of the following tracheophytes are leafless?

• A. Psilopsida
• B. Lycopsida
• C. Sphenopsida
• D. Prteropsida

Explanation: Psilopsida, represented by Psilotum, has a simple leafless sporophyte with naked dichotomously branched stems. Lycopsida and Sphenopsida possess small leaves, while Pteropsida includes well-developed ferns with fronds, so students may incorrectly choose one of those groups.

1735. Sporangia of which of the following tracheopytes develop singly on the upper side of sporophylls which may or may not be arranged to form strobili_____________?

• A. Psilopsida
• B. Lycopsida
• C. Sphenopsida
• D. Prteropsida

Explanation: In Lycopsida, sporangia occur singly on the upper surface of sporophylls, and the sporophylls may be arranged into compact cones called strobili. Sphenopsida is a common distractor because it also forms strobili, but its sporangia are borne on specialized sporangiophores rather than ordinary sporophylls.

1736. Which of the following group of tracheophyta has expanded or scale like leaves which are alwaysed arranges in whorls?

• A. Psilopsida
• B. Lycopsida
• C. Sphenopsida
• D. Prteropsida

Explanation: Sphenopsida has reduced, scale-like leaves arranged in whorls around the stem, as seen in Equisetum. Lycopsida also has small leaves, but they are generally arranged differently and are not characteristically whorled in this way.

1737. Stem of Psilophyton an example of psilogsida is differentiated into an underground rhizome and an aerial part both of which are _________ branched

• A. Isotomous
• B. Dichotomously
• C. Trichotomously
• D. Multichotomously

Explanation: Psilophyton has an underground rhizome and an aerial axis that repeatedly divides into two equal branches, a pattern called dichotomous branching. Isotomous describes equal branching more precisely, so students may choose it, but the standard classification term asked for here is dichotomous.

1738. Maize is an example of_________________?

• A. Monocot
• B. Dicot
• C. Gymnosperms
• D. none of these

Explanation: Maize is an angiosperm with one cotyledon, parallel leaf venation, scattered vascular bundles, and floral parts commonly in multiples of three, all characteristic of monocots. Students may choose dicot because maize is a flowering plant, but flowering plants include both monocots and dicots.

1739. Which of the following statement about dicots is incorrect _________________?

• A. They have 4 or 5 sepals and petals or their multiple.
• B. They have parallel vein pattern on their leaves
• C. They are both herbaceous and woody
• D. Vascular bundles are ring shaped in their stems.

Explanation: Dicots generally have reticulate or net-like leaf venation, whereas parallel venation is a typical monocot feature. Students may choose the vascular-bundle statement, but dicot stems characteristically have vascular bundles arranged in a ring, so that statement is correct.

1740. The first cell of the sporophyte generation is______________?

• A. Oospore
• B. Spore mother cell
• C. Spore
• D. Gamete

Explanation: The sporophyte begins with the diploid zygote, also called the oospore, formed by fusion of male and female gametes. A spore is produced later by the sporophyte, so students who confuse the two generations may choose spore.