AIPMT 2016 Sample Questions
For all you pre-medical aspirants, here are a few sample questions from the chapter in Biology called Morphology of Flowering Plants. Here are 25 AIPMT 2016 sample questions any pre-medical aspirant should be able to solve. Each question is followed by its answer and a detailed explanation. Well quiz on..
Prop roots are roots developing from the branches for support as in Ficus religiosa (Peepal).
Pneumatophores are negatively geotropic roots. These arise from lateral roots in plants which grow in swampy areas(Rhizophora). These are helpful in respiration hence called breathing roots.
Coralloid roots are negatively geotropic roots. They form symbiotic association with N2 – fixing cyanobacteria or blue green algae. Eg. Cycas.
The clinging roots are found in the epiphytic plants. This root fixes the plant on the bark of the tree. It also absorbs little nutrients found on the tree bark. Eg. Pepper.
The figure is that of a sun flower. The sunflower is a typical head inflorescence. Head or capitulum is the characteristic feature of the family asteraceae.
The main axis of the capitulum is flattened or even suppressed. It bears a group of sessile, very small flowers or florets. Generally all florets are attached to flat surface of receptacle. It can be divided into marginal (ray florets) and central (disc florets). The complete inflorescence looks like a single flower. It is surrounded by involucre of bracts. Ray florets are zygomorphic, pistillate, epigynous. Whereas disc florets are sessile, actinomorphic, hermaphrodite, epigynous flowers.
The peduncle in the umbel inflorescence is unbranched. It grows indefinitely. The tip of the peduncle is highly condensed. Flowers are numerous. They appear to be arising from the same point.
A corymb is a raceme in which the pedicels of the lower flowers are longer than those of the upper flowers. So, the inflorescence has a flat-topped appearance overall.
A spadix is a type of spike inflorescence. It has small flowers borne on a fleshy stem enclosed by brightly coloured bracts. These bracts are called spathe. Spadix are typical of the family Araceae.
Cyathium is an inflorescence consisting of a cup-shaped involucre. It encloses an apetalous, pistillate flower surrounded by several staminate flowers.
Cyathium is a special type of inflorescence. Cyathium inflorescence is the characteristic feature of the family euphorbiaceae. It has a cup shaped called involucre with a single female flower surrounded by several male flowers. A nectar secreting gland is present at the rim of the involucre.
The distribution of veins and the veinlets in a leaf blade is called venation. It is of two types namely reticulate venation and parallel venation. In reticulate venation the main vein of leaf forms numerous irregular branches and as a result a net like arrangement is formed like dicots. In parallel venation veins are arranged in parallel to each other.
The mode of arrangement of sepals or petals in floral bud is known as aestivation. This is called so with respect to the other members of same whorl . The main types of aestivation are valvate, twisted, imbricate and vexillary.
A period of dormancy in the metabolic activities exhibited by the living organisms is called hibernation.
The arrangement of ovules within the ovary is called as placentation. Phyllotaxy is the arrangement of leaves on both main stem and the branches.
The fruit is the matured or ripened ovary. It develops after fertilization with or without seeds. Broadly, they are divided into three groups – simple, aggregate and composite. Simple is formed from a flower having a single pistil. Aggregate is from a flower having polycarpellary apocarpous gynoecium. Composite is from a whole inflorescence.
Composite fruits are formed from the whole inflorescence. Here the flowers are closely packed. Hence it is called as multiple fruit. They are of different types – sorosis and syconus.
When the gynoecium is having multiple and distinct carpels, it is called apocarpous. A fruit, such as the strawberry or apple, that includes parts other than the ripened ovary is pseudocarp.
Adventitious roots are roots that occur on plant material other than the actual primary root of a plant. These roots often grow from leaf and/or stem cuttings and can develop with or without the assistance of growth hormones.
Leaves of Bryophyllum, Begonia and Kalanchoe produce buds by means of which they give rise to new plants by vegetative propagation. In these cases when leaf lamina touches the ground, the leaf margin at point produces roots and form a bud that grows into a new plant.
A flower is termed actinomorphic when its symmetry remains undisturbed if one cuts the flower into two halves through any vertical plane passing through the axis.
Here the Fabaceae, Liliaceae and Papilionaceae has zygomorphic flowers whereas Brassicaceae and Solanaceae are having actinomorphic flowers.
The flowers of Brassicaceae are bisexual and actinomorphic or occasionally zygomorphic. The perianth consists of a calyx of 4 distinct sepals and typically a corolla of 4 distinct petals and the superior ovary is usually 2-loculed and bears few to many ovules on parietal placentae. The family Solanaceae has got the flowers that are bisexual and actinomorphic. The perianth and androecium whorls generally are isomerous and usually are 5 merous. They have the persistant calyx retained in the fruit. gynoecium consists of a single compound pistil of 2 carpels, a single style, and a superior ovary with 2 or rarely more locules by false partitioning, each with nearly always numerous axile ovules.
The flowering plants or seed plants are called phanerogams. Their general characters are as follows:
The plant body is differentiated into root, stem and leaves. Plants bear visible reproductive structures. These are cones and flowers. Phanerograms are the vascular plants. These are more advanced than cryptogams. Plants bear specialized sporophylls. Plants reproduce sexually by gametes. Male and female gametophytes are small and dependant on sporophyte for nutrition. Fertilization is of siphonogamous type.
Cryptogams are the lower form of plants. They do not bear conspicuous reproductive structures like seed. Thallophytes are those plants which have thallus. This means they have plant body ( Algae, Lichen and Fungi) which are not differentiated into root, stem and leaves. Heliophytes are those plants which need full sunlight for good growth. Bryophytes are the simplest and the most primitive members of embryophyta. It includes liverworts, hornworts and mosses.
The correct match is as follows:
|(A) Hibiscus rosa- sinensis||(R) Malvaceae.|
|(B) Lepidium sativum||(S) Brassicaece.|
|(C) Tridax procumbens||(T) Asteraceae.|
|(D) Vetiveria zizinoides||(P) Poaceae.|
|(E) Gloriosa superba||(Q) Liliacea.|
Here some plants are enlisted with their respective families.
Tap roots are modified into fleshy, nodulated, pneumatophores and root buttress. When the root becomes swollen and fleshy for storage, they are called fleshy roots. Fleshy roots may be Conical, Fusiform, Napiform and Tuberous. Carrot shows conical roots. Conical roots are swollen at the base and narrow at the apex.
Napiform roots have very thick upper portion and tapers in the lower end.
Fusiform roots are thicker in the middle and tapers at both ends. This is so food can be stored.
Coralloid roots are negatively geotropic roots. It forms symbiotic association with nitrogen fixing cyanobacteria or blue green algae as in Cycas.
Phyllotaxy means the arrangement of leaves on both main stem and branches. Phyllotaxy facilitate the leaves to obtain maximum light for the photosynthesis.
When the leaves are arranged in pairs at each node it is known as opposite phyllotaxy. It is of two type –
When the opposite leaves arise in the same plane at successive nodes, it is said to be opposite superposed phyllotaxy.
When each opposite pair of leaves are at right angles to each other, phyllotaxy is said to be opposite decussate.
Alternate Phyllotaxy is the form of arrangement where a single leaf arises from each node. The consecutive leaves are produced in a spiral manner around the stem.
If more than two leaves occur at a node, the phyllotaxy is said to be whorled.
Flower is the modified shoot which is the unique characteristic of the angiosperms. The flower is meant for sexual reproduction and for this reason they have colourful parts to attract the pollinators. A typical flower shows four sets of members arranged in successive whorls. These are calyx( sepals), corolla( petals) , androecium and gynoecium. usually the corolla is the whorl which is colourful but sometimes calyx become colouful resembling the corolla. This is called petalloid.
In some flowers caly and corolla are undifferentiated and can not be distinguished. They constitutes the perianth. A tepal is the term used to identify one of the outer parts of a flower (collectively the perianth) when these parts cannot easily be divided into two kinds, sepals and petals. Epiphyllous is the condition where stamens united with the perianth leaves as in onion. circinate vernation is denoting leaves or fronds that are rolled up with the tip in the centre, for example the young frond of a fern.
The placenta is the parenchymatous cushion present inside the ovary where ovules are borne. Placentation is the arrangement of ovules within the ovary. There are different types of placentations – marginal, parietal, axile, free central, basal and superficial.
Marginal placentation: The placenta bearing the ovules in a row develops along the junction of the two margins of the folded carpels.
Parietal placentation: The placenta is seen on the inner surface of the ovary at the junctions of the carpels.
Axile placentation: The walls of the carpels in the centre of the ovary are united to form an axis. This axis bears the placentae.
Free central placentation: The partition walls are found in the early stage of the ovary forming chambers. This disintegrate later on, the ovary becomes unilocular.
Basal placentation: The ovary is unilocular. The placentae bearing a single ovule develop at the base of the ovary.
Superficial placentation: The placentae develop all round the inner surface of the partition walls. A large number of ovules are borne on the placentae without any specific order.
All the given plants belong to Monocotyledons.
Monocotyledons are divided into 7 series.
Orchids belong to the family orchidaeae coming under the series Microspermae. Coconut belong to the family palmae of Calycineae. Asparagus is a genus of plants in the family asparagaceae, an angiosperm family that is not universally recognized, as often the plants involved are treated as belonging to the family Liliaceae (Lily family) of Coronarieae and Canna belongs to zingiberaceae of Epigynae.
Fabaceae has been divided into three subfamilies: Caesalpinioideae, Mimosoideae, and Faboideae (or Papilionoideae), Standard, wings and keels are the specilised petals in papilionaceous flower.
Papilionaceous is a flower from the Papilionaceae family (as in the bean or pea) with a corolla, usually with five petals that include a large upper petal, the vexillum(standard petal), enclosing two lateral wings resembling a butterfly and a lower keel petals which are united.The characteristic aestivation of this flower is vexillary imbricate.
When the largest petal overlaps the two lateral petals; which in turn overlap the two smallest anterior petals, this arrangement is called vexillary.
A group of flowers born on a common axis is called inflorescence. Inflorescences are classified into four type as Racemose, Cymose, Mixed and special.
Racemose inflorescence is indefinite or indeterminate. Here the terminal bud will not modify into a flower and the flowers develop in acropetal succession (mature flowers are towards the base and the younger comes towards the tip of the peduncle).
Cymose inflorescence is definite or determinate inflorescence. Here the terminal bud is modified into a flower. Flowers develop in basipetal succession (mature flowers are towards the apex and younger flowers are towards the base).
Stalk of the flower is called pedicel. Flowers with stalk is called pedicellate flowers. Flowers without stalk are sessile flowers.
Monochasial cyme is a type of infloresence. Here peduncle ends in a flower, below which one lateral branch develops from the axile of a bract. This branch also ends up in a flower.
In Dichasial cyme growth of the peduncle terminates in a flower, below which two branches develop laterally in the axils of opposite bracts. These branches also ends up in flowers.
The placenta is the parenchymatous cushion present in the ovary on which the ovules are arising. The arrangement of the ovule in the ovary is known as the placentation. There are different kinds of placentations namely marginal, axile, basal, parietal, free central and superficial.
The axile placentation is the arrangement of ovules in the ovary which is a polycarpellary syncarpous. The ovary is many chambered and the number of chambers correspond to the number of carpels. The walls of the carpels are united at the centre to form an axis which bears the placenta. E.g., Petunia.
The visible potions as ‘leaves’ in Acacia are actually a modified leaf stalk (phyllodes). These are flattened and enlarged. The true leaves are bipinnately compounded. They are only visible on newly germinated seedling. Phyllodes is the modified petiole or rachis of a leaf. It is modified into a green flat structure for the puropose of photosynthesis. The lamina of such leaves are poorly developed. For example in Acacia melanoxylon, the petiole is flattened, green and forms a phyllode.
The correct match is as follows:
(e) Water lilly.
(f) Mango tree.
These are some of the technical words related to flower with examples.
A flower is the modified shoot for the purpose of sexual reproduction. A typical flower has 4 types of whorls namely calyx (sepals), petals (corolla), androecium (stamens) and gynoecium (carpels).
In some flowers there will not be sepals and petals. Such flowers are known as achlamydeous flowers. Example – Willow.
Monochlamydeous flowers are having a perianth of one whorl of members; not having a separate calyx and corolla.
Dichlamydeous flowers are flowers which are having two coverings, a calyx and a corolla.
The suffix -cyclic is used to denote the number of whorls contained within a flower. A typical cyclic flower is a flower type formed out of a series of whorls; sets of identical organs attached around the axis at the same point.
Some flowers contain flower parts with a spiral arrangement. Such flowers are not cyclic. However in the common case of spirally arranged sepals on an otherwise cyclic flower, the term hemicyclic may be used. Example: Rose.
Acyclic flowers are having flower parts arranged in a spiral rather than a whorl. Example: Annonaceae.
Polysexual flowers are those flowering plants having both bisexual and unisexual flowers. Example: compositae flowers.
A group of flowers borne on a common axis is called inflorescence. Otherwise mode of arrangement of flowers on an axis is called inflorescence. They are of two types – racemose and cymose.
Racemose: Here the inflorescence main axis continues to grow. The flowers are borne laterally in a acropetal succession.
Cymose : The main axis of the inflorescence terminates in a flower. The flowers are borne in a basipetal order.
Every organism has developed during evolution. They develop a range of mechanisms against adverse environmental conditions or infectious organisms and predators. There are many defensive mechanisms seen in plants. They are thorns, spines, prickles, bristles etc. These structures are modifications of stem. They help to protect plants from the hazardous situations.
Thorns are modified stem. They are endogenous in origin. Thorns protect plant against attack by herbivorous animals. They are with the vascular cylinder. Spines are modified leaves with vascular strand. Prickles are superficial hard structures borne over surface stem and leaves and vascular cylinder is absent. Bristles (stinging hairs) are modifications of hairs. It is present where deposition of silica or calcium carbonate occurs.
Other defensive mechanisms are Glandular hair with sticky substances (Jatropha, Boerhaavia, tobacco). Dense coating of hair or stiff hair, repulsive to animals (Cud weed (Gnaphalium), many Cucurbits). Presence of poisonous and irritating substances(Nerium, Ficus, colocasia). Alkaloids as in poppy, datura, bitter taste in neem. Geophilous habits (Zingiber). Presence of ants on plants (myrmecophily). Mimicry as in aroids resembles spotted snakes.
Orchids are one of the largest families coming under orchidaceae od Monocot.
Sagittaria sp is known as arrowhead. It is due to the shape of its leaves. It is a flowering plant in the family Alismataceae of monocot.
Dracaena comes under asparagaceae of monocots.
The Sunflower family contains the largest number of plant species. It comprises of 950 genera and about 20,000 species. Out of these about 1000 are from India. The Sunflower family includes shrubs such as Coyotebrush as well as herbs such as Sunflowers, Daisies, Asters, Thistles, and Dandelions. Asteraceae, the sunflower family, is one of the easiest plant families to recognize. It is so because of their compound flower heads. While it appears to be a single flower.
The Asteraceae is one of the largest plant families among dicot families. It is second only to the Orchidaceae in flowering plants.
The correct answer is
(A) Hibiscus rosa –sinensis
(B) Lepidium sativum
(C) Tridax procumbens
(D) Vetiveria zizinoides
(E) Gloriosa superba
These are some of the families with their examples.
Flowers are the specialized reproductive structures of angiosperms. Flowers have different types of florals whorls. They are calyx (sepals), corolla (petals), androecium (stamens) and gynoecium (carpels). These whorls are attached to each other in certain specific way. This way is an identification mark of each every family or species.
The stamen is the pollen-producing reproductive organ of a flower. A stamen typically consists of a stalk called the filament and an anther. Depending on the attachment of stamens with the perianth or petals, they are of two types.
(i)When stamens are attached to the petals, the arrangement is called epipetalous, e.g. brinjal.
(ii)When stamens are attached to the perianth, the arrangement is called epiphyllous, e.g. lily.
In Liliaceae, the petals and sepals are united together to form the tepals. The term tepal is usually applied when the parts of the perianth are difficult to distinguish. E.g. the petals and sepals share the same color, or the petals are absent and the sepals are colorful.
Stamens can also be adnate (fused or joined from more than one whorl).
Episepalous flowers means the stamens are attached to the sepals. The stamen whose filaments are fused to form a single tube-like structure is known as monadelphous stamen. The single tube-like structure is called staminal tube. A stamen that has its filaments united into two sets is called diadelphous. Polyadelphous stamen is the one having united filaments. These filaments are arranged in three or more groups. Adnate stamen means fused or joined to more than one whorl.
With the medical entrance such as A.I.P.M.T 2016, A.I.I.M.S, J.I.P.M.E.R and the others fast approaching, many more such test should be practiced by you. This is so you can consolidate your knowledge and to keep yourself updated.
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