1st Year NotesBiology class 11th

1st year biology Chapter 9 Kingdom Plantae

1st year biology Chapter 9 Kingdom Plantae Question an Answers

Short and Simple Question an Answer

Q.1 What is Oospore?

Ans. A thick walled zygote that is formed after the fertilization of an Oosphere.

Q.2 Define a spike?

Ans. A racemose inflorescence in which the flowers are sessile and borne on an elongated axis as in wheat.

Q.3 Are all the seed plants also known as the flowering plants?

Ans. No, only the angiosperms are also called flowering plants but not the gymnosperms.

Q.4 Which are the probable ancestors of bryophytes?

Ans. These are the green algae.

Q.5 Name the most primitive (earliest) group of vascular plants?

Ans. It is the Psilopsida (Psilophyta).

Q.6 Name a heterosporous lycopsid?

Ans. It is the Selaginella.

Q.7 What is a sorus in ferns?

Ans. A group of sporangia is known as a urity on Adiantum..

Q.8 What is prothallus?

Ans. The gametophyte of fern is also called as the prothallus. It has leaf like shape.

Q.9 What does a stamen of flower consist of?

Ans. The stamen consists of a filament and an anther.

Q.10 From which part of the flower fruit is formed?

Ans. The fruit is formed from the ovary of the flower.

Q.11 How many sperms are carried by one pollen tube?

Ans. One pollen tube carries two sperms.

Q.12 What is scientific name of Kachnar?

Ans. It is Bauhinia variegata.

Q.13 Which drugs are obtained from Atropa belladona and Datura?

Ans. These drugs are atropine and daturin.

Q.14 What are the names of the pea family?

Ans. The pea family is called Papilionaceae or Fabaceae.

Q.15 Write down the names of the parts of typical carpel?

Ans. The parts of a typical carpel of flower are the ovary, style and stigma.

Q.16 What is a sporophyll?

Ans. A leaf bearing sporangia is called a sporophyll.

Q.17 Quote some examples of important ferns?

Ans. These are Dryopteris, Pteridium Adiantum and Pteris.

Q.18 Which vascular plant first evolved true roots and leaves?

Ans. These were the lycopods (lycopsids).

Q.19 Classify horsetails?

Ans. Kingdom Plantae, division Tracheophyta and sub-division Sphenopsida.

Q.20 What is a thallus i.e., thalloid plant body?

Ans. The body of plant which is not differentiated into root, stem and leaves is called a thallus or thalloid plant body.

Q.21 What are paraphyses in mosses?

Ans. In mosses, paraphyses are the sterile hairs which lie between the antheridia and the archegonia.

Q.22 How do the psilopsids manufacture their food when they lack leaves?

Ans. The aerial branches of psilopsids are green and photosynthetic.

Q.23 Explain indusium?

Ans. Indusium is a flap of tissue that partially or completely covers each sorus (group of sporangia) in certain ferns.

Q.24 Explain racemose inflorescence?

Ans. A racemose inflorescence is that in which the flowers are formed on individual pedicels on the main axis.

Q.25 Define didynamous condition?

Ans. Having two long stamens and two short stamens in single whirl.

Q.26 What is perianth?

Ans. The structure that protects the developing reproductive parts of the flower.

Q.27 What is the principal function of xylem?

Ans. The principle function of xylem in the plants is the upward transportation of water and solutes.

Q.28 What are the seed producing plants normally called?

Ans. The seed producing plants are normally called spermatophytes.

Q.29 What is a compound leaf?

Ans. A leaf, the blade (lamina) of which is divided into several pieces or leaflets (pinnae) is called a compound leaf.

Q.30 Where do the ferns grow?

Ans. The ferms grow in moist and shady places on the hills and in the plains.

Q.31 How are ferns better adapted to life on land than liverworts and mosses?

Ans. (i) Reproduction is not dependent on water.
(ii) Sporophyte and gametophyte are independent generations.

Q.32 Which of the following are nutritionally self supporting?

Ans. Mature liverwort and moss gametophyte.
(i) Mature liverwort and moss gametophyte.
(ii) Mature liverwort and moss sporphyte.

Q.33 The chance of survival and development of wind-blown pollen grains are much less than those of spores of Adiantum. Comment on this statement?

Ans. Although spores of Adiantum are also dispersed by wind, however when a spore falls on a moist soil, it germinates at a suitable temperature and produces a haploid gametophyte or prothallus. But in case of wind-blown pollen grains, if they fall on soil, they are wasted. For their survival and development it is must for them to fall on stigma of flower.

Q.34 Account for the fact that megaspores are large and microspores are small?

Ans. Megaspores are large since they have to store food for the growth of embryo.

Q.35 What important advances have angiosperms made towards the seed plant life?

Ans. One of the most significant events in the history of land plants was the development of seed habit. It was an important change in the reproductive system of the vascular plants. Technically as seed may be defined as a fertilized ovule. An ovule is an integumented indehiscent megasporangium, integuments are specialized protective coverings around megasporangium which vary in number. Megasporangium is also called Nucellus. All seed producing plants are called spermatophytes.
Major Steps in Evolution of Seed:
The major steps associated with the evolution of seed habit are as follows:

1.The evolution of heterospory.

2.Retention and germination of megaspore within the megasporangium.

3.Developments of protective layers around megasporangium.

4.Reduction to a single functional megaspore per sporangium.

5.Development of an embryo sac within the sporangium.

6.Modification of distal end of megasporangium for pollen capture.

Q.36 Write a note on the alternation of generations?

Definition: It is the phenomenon in the life cycle of many plants in which haploid gametophyte and diploid sporophyte regularly alternate with each other.
Explanation: In the life history of bryophytes, pteridophytes and spermatophytes, there are two distinct phases or generations.
(i) Gametophyte: The gametophyte is the dominant generation because it is more conspicuous. It produces gametes called spermatozoid and eggs and is, therefore, called gamete producing generation. A haploid spermatozoid fuses with a haploid egg to produce diploid oospore. The oospore produces a totally different plant called sporophyte (also called sporogonium).
(ii) Sporophyte: The sporophyte is a less conspicuous generation, which is usually differentiated into foot, seta and capsule. Spores develop within the capsule by meiosis from spore mother cells. The sporophyte produces spores and is, therefore, called spore producing generation. Each spore on germination gives rise to the gametophyte.
It is should be noted thatthe gametophyte or haploid stage begins with spores and ends at gametes, whereas the sporophyte begins with oospore and ends at spore mother cell.
Significance of Alternation of Generations: Alternation of generation is very
(iii) It promotes the chance of survival of organisms.
(iv) The populations become increasingly better adapted to environment.

Q.37 What is the importance of the following?
(i) Seed
(ii) Double fertilization
(iii) Heterospory

Ans. Seed: Seed is very important structure in angiosperms as it leads to next generation. It has protective coverings so it can tolerate unfavourable condition. Whenever it finds suitable environment it will germinate.
Double Fertilziation: It is the phenomenon in life of angiosperms in which one sperm
fertilizes the egg forming zygote while other sperm fertilizes fusion nucleus (diploid nucleus) to form a triploid endosperm. The zygote leads to the formation of embryo and then seed while endosperm has stored food which is used for the development of embryo. In certain cases endosperm is the part of the seed (e.g., corn) and provides food for the
germination of seed.
Heterospory: It is the condition in which plants make two type of spores i.e., microspores and megaspores, which are different morphologically, structurally and funtionally. They lead to more variations in the next generations.

Q.38 To what does alternation of generation refer in the plants? Define sporophyte and gametophyte. With which stage is an adult animal comparable? How are they reproductively dissimilar?

Ans. Alternation of Generation: It is the phenomenon in the life cycle of many plants in which haploid gametophyte and diploid sporophyte regularly alternates with each other.
Sporophyte and Gametophyte: The spore-producing generation is called sporophyte while gamete producing generation is called gametophyte.
Reproductive Dissimilarity between Sporophyte and Gametophyte: The sporophyte is diploid, multicellular generation which produces spores by meiosis. The spores develop into gametophyte. The gametophyte is haploid, multicellular generation which produces gametes by mitosis. The gametes develop into sporophyte.

Q.39 What is a seed? Why is the seed a crucial adaptation to terrestrial life?

Ans. Seed: Technically a seed may be defined as a fertilized ovule. An ovule is an integumented indehiscent megasporangium. Integuments are specialized protective coverings around megasporangium which vary in number.
Seed a Crucial Adaptation to Terrestrial Life: The seed offers maximum degree of protection to a developing embryo under the unfavourable terrestrial environment. The development and evolution of seed habit was a great success and a giant leap which ultimately enabled plants to colonize land permanently.

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