NEET Biology Morphology and Anatomy of Flowering Plants MCQs Set 01

Answer: (b) Axillary bud

Explanation:
1. A bud that forms in the angle between a leaf and the stem is called an axillary bud.
2. It can grow into a branch or a flower, while the apical bud at the tip makes the main axis grow in length.

Teacher's Note:
1. Axillary means in the axil, the angle between leaf and stem.
2. Branching of a plant depends on activity of axillary buds.

Answer: (d) Tuber - Ginger

Explanation:
1. Chrysanthemum propagates by suckers, Colocasia has a corm, and doob grass (Cynodon) spreads by runners.
2. Ginger is a rhizome (underground stem with nodes and internodes), whereas a tuber is the swollen stem tip of potato.
3. So option (d) is incorrect.

Teacher's Note:
1. Ginger, turmeric and banana have rhizomes.
2. Potato is the classic stem tuber.

Answer: (b) Liliaceae

Explanation:
1. Liliaceae includes lily, tulip, Asparagus, Aloe, Allium (onion, garlic) and Colchicum.

Teacher's Note:
1. Liliaceae is the main monocot family in the syllabus.
2. Remember its tepals and trimerous flowers.

Answer: (b) Coconut

Explanation:
1. Coconut is a drupe in which the mesocarp is fibrous (coir) and the endocarp is hard.
2. In mango the mesocarp is fleshy, and cotton and datura are capsules.

Teacher's Note:
1. Coir comes from the fibrous mesocarp of coconut.
2. Do not confuse it with the edible endosperm.

Answer: (a) presence of a false septum

Explanation:
1. Mustard (Brassicaceae) has a superior, bicarpellary, syncarpous ovary with parietal placentation.
2. A thin false septum (replum) divides it into two chambers.
3. Axile placentation and an epigynous position are not found, so only (a) is correct.

Teacher's Note:
1. A false septum is a feature of the cruciferous ovary.
2. Hypogynous flowers have a superior ovary.

Answer: (c) Trimerous flowers

Explanation:
1. Monocot flowers are typically trimerous, with floral parts in threes.
2. Liliaceae flowers show 3+3 perianth, 3+3 stamens and 3 carpels.
3. Hypogyny, actinomorphy and bisexuality are also seen in many dicots.

Teacher's Note:
1. Trimery is the key monocot floral feature.
2. Dicot flowers are tetramerous or pentamerous.

Answer: (c) Mulberry

Explanation:
1. A catkin is a spike-like raceme with a long drooping axis bearing unisexual flowers, as in mulberry.
2. Radish bears a raceme and grass a spike (spikelet).

Teacher's Note:
1. Mulberry, birch and oak bear catkins.
2. They are mostly wind pollinated.

Answer: (c) Corymb and umbel

Explanation:
1. Corymb and umbel are both racemose types, with unlimited growth of the main axis.
2. Hypanthodium, cyathium and verticillaster are cymose, while catkin, raceme and spike are racemose.
3. Only option (c) pairs two of the same kind.

Teacher's Note:
1. Racemose means the axis keeps growing and the oldest flowers are at the base.
2. Cymose means the axis ends in a flower.

Answer: (c) Fusiform root

Explanation:
1. Fusiform roots are spindle shaped and swollen in the middle, as in radish.
2. Conical roots (carrot) taper from top to bottom, and napiform roots (turnip, beet) are almost spherical at the top.

Teacher's Note:
1. Fusiform means spindle shaped.
2. Radish is the standard example.

Answer: (a) Xylem

Explanation:
1. Xylem vessels, tracheids and fibres have lignified secondary walls.
2. Lignin makes the walls strong and waterproof and helps the xylem support the plant.

Teacher's Note:
1. Lignin gives wood its hardness.
2. Phloem walls are mostly cellulosic.

Answer: (b) Phellem

Explanation:
1. Phellem (cork) cells are dead at maturity, with suberin deposited on their walls.
2. Collenchyma, phloem and xylem parenchyma are living tissues.

Teacher's Note:
1. Cork is the outer layer of bark and is impermeable to water.
2. Xylem vessels and tracheids are also dead.

Answer: (d) Phellem, phelloderm and phellogen

Explanation:
1. Periderm is the protective tissue of secondary growth.
2. It consists of cork cambium (phellogen), cork (phellem) formed outward and secondary cortex (phelloderm) formed inward.

Teacher's Note:
1. Phellogen produces phellem to the outside and phelloderm to the inside.
2. Bark is all the tissue outside the vascular cambium.

Answer: (b) Temperate

Explanation:
1. In temperate regions cambium is highly active in spring (large vessels, light wood) and less active in autumn (small cells, dark wood).
2. The difference between seasons produces clear rings.
3. Tropical regions have little seasonal change, so the rings are indistinct.

Teacher's Note:
1. Counting annual rings gives the age of a tree.
2. Distinct seasons are needed for distinct rings.

Answer: (b) protoxylem lies towards the periphery and metaxylem lies towards the centre

Explanation:
1. In exarch xylem the first formed protoxylem is at the outer side (towards the periphery).
2. The later formed metaxylem lies towards the centre.
3. Roots have this arrangement.

Teacher's Note:
1. Exarch means the xylem develops from outside to inside.
2. Mesarch is the case where protoxylem is surrounded by metaxylem, as in ferns.

Answer: (a) Roots

Explanation:
1. Cuticle is a waxy layer on the epidermis of aerial organs to prevent water loss.
2. The root epidermis absorbs water, so it has no cuticle (and no stomata).

Teacher's Note:
1. Root hairs need to be permeable to water.
2. Leaves and stems have a cuticle.

Answer: (b) Calyptrogen

Explanation:
1. In monocot roots (and grasses) a separate group of cells, the calyptrogen, gives rise to the root cap.
2. The dermatogen forms the epidermis, periblem forms the cortex and plerome forms the stele.

Teacher's Note:
1. Calyptrogen means cap-maker.
2. In dicot roots the root cap arises from the dermatogen.

Answer: (c) Peach - inferior ovary

Explanation:
1. Mustard has a hypogynous flower with a superior ovary.
2. Rose and peach are perigynous, with the ovary half inferior (NCERT wording).
3. Cucumber is epigynous with an inferior ovary.
4. So the pair "Peach - inferior" is the incorrect one.

Teacher's Note:
1. Hypogyny gives a superior ovary, epigyny gives an inferior ovary, and perigyny gives a half inferior ovary.
2. Guava, cucumber and sunflower have epigynous flowers.

Answer: (a) Sugarcane

Explanation:
1. Stilt roots arise from the lower nodes of the stem and support the plant, as in sugarcane, maize and Pandanus.
2. Sweet potato has tuberous adventitious roots, and Asparagus has fasciculated roots.

Teacher's Note:
1. Prop roots hang from branches (banyan); stilt roots grow obliquely from the lower nodes.
2. Both give mechanical support.

Answer: (a) Perigynous

Explanation:
1. In a perigynous flower the gynoecium lies in the centre, and the calyx, corolla and androecium are on the rim of the thalamus at about the same level.
2. The ovary is half inferior.
3. Rose and plum are examples.

Teacher's Note:
1. Hypogyny: gynoecium at the highest position. Epigyny: other parts above the ovary.
2. Protogyny is about the maturation time of stigma and anther.

Answer: (d) Bicarpellary, superior ovary

Explanation:
1. Solanaceae flowers have a bicarpellary, syncarpous, superior ovary with swollen placentae.
2. Didynamous stamens belong to Lamiaceae, a capitulum to Asteraceae, and tetradynamous stamens to Brassicaceae.

Teacher's Note:
1. Epipetalous five stamens and a persistent calyx are also characteristic.
2. Match each family with its stamen type.

Answer: (c) Trifolium and Sesbania

Explanation:
1. These are the features of Fabaceae (Papilionoideae).
2. Trifolium (clover) and Sesbania are members of this family.
3. Petunia and tobacco are Solanaceae, Brassica is Brassicaceae, and Colchicum is Liliaceae.

Teacher's Note:
1. Diadelphous stamens are in two bundles (9 + 1).
2. Papilionaceous means butterfly-like, with standard, wings and keel.

Answer: (d) The fruit is a legume and the seeds are non-endospermic

Explanation:
1. A floral diagram shows the number, fusion and arrangement of sepals, petals, stamens and carpels, and the symmetry and sex of the flower.
2. Fruit type and seed structure are not shown, because they develop after fertilisation.
3. So (d) cannot be seen.

Teacher's Note:
1. A floral diagram depicts only the floral whorls.
2. Fruit and seed details come from the floral formula's family description.

Answer: (c) Meristem

Explanation:
1. Meristems are regions of actively dividing cells, such as the apical meristem at the tips of root and shoot and the lateral meristems (cambium).
2. A tissue is a group of similar cells and an organ is made of several tissues.

Teacher's Note:
1. Meristematic cells are small, thin-walled and lack a large vacuole.
2. They continue to divide throughout the life of the plant.

Answer: (b) Sclereids

Explanation:
1. The gritty particles in pear fruit are sclereids (stone cells).
2. They are dead cells with extremely thick, lignified walls and a narrow lumen.
3. Fibres are long and tapering, while collenchyma and parenchyma are living cells.

Teacher's Note:
1. Sclereids are also found in seed coats, nut shells and guava pulp.
2. They give hardness to those tissues.

Answer: (b) A, C are correct

Explanation:
1. (A) is true: perforations in the common walls join vessel members into a vessel.
2. (B) is false: it describes sclerenchymatous fibres, whereas xylem parenchyma cells are living with thin walls.
3. (C) is true: ray parenchyma carries water radially.
4. (D) is false: gymnosperms have tracheids but lack vessels.

Teacher's Note:
1. Gymnosperms lack vessels, not tracheids.
2. Xylem parenchyma stores food and conducts water radially.

Answer: (d) Coconut

Explanation:
1. Marchantia, papaya and date palm have male and female organs on separate individuals, so they are dioecious.
2. Coconut bears both male and female flowers on the same plant, so it is monoecious.

Teacher's Note:
1. Monoecious: separate unisexual flowers on the same plant (maize, castor, coconut).
2. Dioecious plants do not have self-pollination.

Answer: (d) Fruiting once

Explanation:
1. A monocarpic plant flowers and fruits only once in its life and then dies, as with bamboo species, annual crops and some biennials.
2. Polycarpic plants flower repeatedly.

Teacher's Note:
1. Monocarpic does not mean a short life, since bamboo can wait for decades.
2. The key point is flowering once.

Answer: (d) 8-celled and 7-nucleate

Explanation:
1. The most common embryo sac is the monosporic, Polygonum type.
2. It has 8 nuclei but 7 cells, because the two polar nuclei are in a single large central cell.
3. So "8-celled and 7-nucleate" is incorrect.

Teacher's Note:
1. Count the cells: 3 antipodals, 2 synergids, 1 egg and 1 central cell = 7.
2. Count the nuclei: 3 + 2 + 1 + 2 = 8.