Students get through AP Inter 1st Year Botany Important Questions 6th Lesson Modes of Reproduction which are most likely to be asked in the exam.
AP Inter 1st Year Botany Important Questions 6th Lesson Modes of Reproduction
Very Short Answer Questions
Question 1.
What is the dominant phase in the life cycle of an angiosperm?
Answer:
The dominant phase in the life cycle of an angiosperm is Diploid sporophytic phase.
Question 2.
What is meant by heterospory? Mention the two types of spores developed in an angiospermic plant?
Answer:
- Production of two types of spores in an angiospermic plant is known as heterospory.
- The two types of spores are Microspores and Megaspores.
Question 3.
Mention the modes of reproduction in Algae and Fungi.
Answer:
- In Algae, vegetative reproduction is by fragmentation. Ex: Spirogyra.
Asexual reproduction is by motile zoospores.
Sexual reproduction is by syngamy. Ex: Cladophora. - In fungi, vegetative reproduction is by fragmentation.
Asexual reproduction is by non-motile spore production.
Sexual reproduction is by gametagial copulation. Ex: Rhizopus
Question 4.
How do liver worts reproduce vegetatively?
Answer:
Vegetative reproduction in liverworts is by fragmentation and gemmae formation.
Question 5.
Mention any two characteristics of bacteria and yeast that enable them to reproduce asexually.
Answer:
- Bacteria reproduces asexually by binary fission. Each cell rapidly grows into an adult.
- east is a single celled fungus. It reproduces asexually by budding. Small buds are produced remain attached initially to the parent cell which, eventually get seperated and mature into new yeast organisms.
Question 6.
Why do we refer to offspring formed by asexual method of reproduction as clones?
Answer:
- Formation of spores during asexual reproduction does not involve two parents.
- So plants produced asexually are called clones.
Between an annual and a perennial plant, which one has a shorter juvenile phase? Give one reason.
- Annual plant has a short juvenile phase than a perennial plant.
- Because its life span is just one year or one season.
Question 8.
Rearrange the following events of sexual reproduction in the sequence in which they occur in a flowering plant: embryogenesis, fertilisation, gametogenesis, pollination.
Answer:
Gametogenesis → Pollination → Fertilization → Embryogenesis.
Question 9.
Is there relationship between the size of an organism and it’s life span?
Answer:
- There is no relationship between size of an organism and it’s life span.
- The mango tree has a shorter life span as compared to a banyan tree, though both are of same size.
Question 10.
Give reasons as to why cell division can or cannot be a type of reproduction in multicellular organisms.
Answer:
- When a unicellular organism undergoes vegetative (or) asexual reproduction, cell division can be a type of reproduction for the production of new organisms.
- Normally in multicellular organisms cell division is essential for growth and development but not for the generation of new plants.
Hence cell division cannot be a type of reproduction in multicellular organisms.
Question 11.
Which of the following are monoecious and dioecious organisms:
a) Date palm b) Coconut c) Chara d) Marchantia
Answer:
a) Date palm – Dioecious;
b) Coconut – Monoecious
c) Chara – Monoecious
d) Marchantia – Dioecious
Question 12.
Match the following given in column A with vegetative propagules given in column B.
Column A – Column B
i) Bryophyllum – a) Offset
ii) Agave – b) Eyes
iii) Potato – c) leaf buds
iv) Water hyacinth – d) fragmentation
v) Chara – e) sucker
vi) Mentha – f) bulbils
Answer:
i) c
ii) f
iii) b
iv) a
v) d
vi) e
Question 13.
What do the following parts of a flower develop into after fertilisation?
a) ovary
b) stamens
c) ovules
d) calyx
Answer:
a) Ovary → fruit;
b) Stamens → drops away,
c) Ovule → seed,
d) Calyx → withers away (or) drops away
Question 14.
Define vivipary with an example.
Answer:
- vivipary: The germination of seed inside the fruit while it is still attached to the parent plant is called vivipary.
- Ex: Rhizophora.
Short Answer Questions
Question 1.
In haploid organisms that undergo sexual reproduction, name the stage in the life cycle where meiosis occurs. Give reasons for your answer.
Answer:
- Meiosis takes place only in diploid stage.
- Because zygote is the only diploid cell in life cycle of such organisms.
- In haploid organisms diploid zygote is formed after fertilization by sexual reproduction.
- The diploid zygote undergoes meiosis to produce haploid spores or zoo spores.
- These zoo spores then undergo mitosis to grow into a mature haploid gametophyte.
Question 2.
The number of taxa exhibiting asexual reproduction is drastically reduced in higher plants (angiosperms) when compared to the lower group of plants. Analyse possible reasons for this situation.
Answer:
- Angiosperms have more structural organisation and have very efficient method of sexual reproduction.
- Asexual reproduction doesn’t create new genetic pools. In the offspimg and they do not have adaptability to adverse conditions.
- Even algae, fungi shift to sexual method to overcome adverse conditions by forming thick walled, resistant zygote to desiccation and damage.
- Sexual reproduction brings out ‘genetic recombination’ and ‘favourable variations’ which helps to withstand the unfavourable and adverse conditions.
Question 3.
Is it possible to consider vegetative propagation observed in plants like bryophyllum, water hyacinth and ginger as a type of asexual reproduction? Give two/three reason.
Answer:
The formation of new plants, from vegetative units like buds, tubers, rhizomes etc is called vegetative propagation.
It can be considered as ‘asexual reproduction’ as it involves in the ‘production of new individuals’. Reasons:
- In asexual reproduction, the offspring forms from a single parent just like in vegetative propagation.
- Asexual reproduction doesn’t involve fusion of male and female gametes.
- In asexual reproduction, the offspring are genetically very similar to parents (clones – exact copy of parents) just like in vegetative propagation.
- Hence, vegetative reproduction can also be considered as asexual reproduction.
Question 4.
‘Fertilisation is not an obligatory event for fruit production in certain plants’. Explain the statement.
Answer:
- Some times fruits are produced from a flower without fertilisation. This phenomenon is called parthenocarpy.
- Development of an embryo from an unfertilised egg is called parthenogenesis.
- So fertilisation is not an obligator event for fruit production. Ex: Banana, Guava, Pine apple.
Question 5.
List the changes observed in angiosperm flower subsequent to pollination and fertilisation. [AP M-16, 17] [IPE- 14,13] [TS May-17]
Answer:
A) Post-Pollination effects:
- The pollen grain germinates on the stigma to produce a pollen tube.
- Pollen tube grows through the tissues of the stigma and style and reaches the ovary.
- Later Pollen tube enters into the ovule by porogamy or chalazogamy or mesogamy.
- After entering into the embrvosac, the pollen tube bursts and releases the two male gametes into the cytoplasm of the synergid.
- The first male gamete fuses with egg and forms a diploid zygote.
- The second male gamete fuses with the second nucleus and forms a PEN.
B) Post-fertilization effects:
- Calyx, corolla, stamens, style and stigma wither and drop away.
- Fertilized ovary develops into fruit. .
- After fertilisation, ovules become seeds.
- Zygote develops into embryo.
- Antipodals degenerate. Synergids degenerate.
- Primary endosperm nucleus becomes endosperm.
- Integuments become seed coats.
- Micropyle of the ovule become micropyle of the seed.
Question 6.
Suggest a possible explanation why the seeds in peapod are arranged in a row where as those in a tomato are scattered in a juicy pulp.
Answer:
- After fertilization, ovules develop into seeds, and ovary turns into fruit.
- In a pea plant, there is marginal placentation. i.e ovules are arranged on a ridge along ventral suture of the ovary. Hence seeds are present in row in Peapod.
- In tomato, axile placentation is seen and ovules are arranged on central axis of ovary. So seeds are scattered in juicy pulp formed from mesocarp and endocarp.
Question 7.
Justify the statement ‘Vegetative reproduction is also a type of asexual reproduction’?
Answer:
- Asexual reproduction doesn’t involve fusion of male and female gametes.
- In algae, moulds and mushrooms, the plant body breaks into smaller portions (fragments) and each fragment develops into mature plant.
- In flowering plants like runner, stolon, sucker, offset, rhizome, corm, tuber, bulbil the reproduc¬tion is vegetative.
- In vegetative reproduction, there is no fusion of gametes.
- Reproduction is by single parent and offsprings are exact copy of their parents.
- Hence, vegetative reproduction is a type of asexual reproduction.
Question 8.
Write a brief account on gametogencsis with examples. [TS M-16]
Answer:
- The process of formation of two types of gametes, male and female is called gametogenesis.
- Gametes are haploid cells(n).
- In some algae, the gametes are similar in appearance and it is not possible to categorize them into male and female gametes. Such gametes are called homogametes Ex: Cladophora.
- In majority of sexually reproducing organisms, the gametes are morphologically distinct and separable into male and female gametes. So, they are called heterogametes.
Ex: Funaria, Pteris, Cycas - Here, the male gametes are called antherizoids and the female gamete is egg.
Question 9.
Give an account of sexuality in organisms.
Answer:
- Sexual reproduction in organisms is by the fusion of gametes from two different individuals.
- Some times gametes produced by the same individual may fuse resulting in self fertilisation.
- When a plant possess both male and female structures it is a bisexual plant.
- When a plant possess organs of one sex, it is called unisexual plant.
- In fungi we use the word homothallic to denote bisexual condition.
- Where as in flowering plants we use monoecious to denote bisexual condition.
- Similarly in fungi heterothallic is the word for unisexual condition.
- In flowering plants we use the word dioecious to denote unisexual condition.
- When male and female flowers are present on the same plant, the plants is monoecious.
Ex: Cucurbita, Coconut. - When male and female flowers are present on different plants, the plant is dioecious.
Ex: Papaya, date palm.
Question 10.
Define (a) Juvenile phase (b) Reproductive phase. |APM-20|
Answer:
a) Juvenile Phase: Juvenile phase is the young phase of the plant body. During this phase plant grows in size vegetatively. Finally it reaches maturity.
b) Reproductive Phase: The phase where the plants start producing flowers is called Reproductive Phase. This is the end of the Juvenile phase.
Question 11.
Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction? [AP May-19] [TS M – 15, 20]
Answer:
Asexual reproduction | Sexual reproduction |
1) It involves single parent only. 2) Gametes are not formed. 3) No gametic fusion. 4) No fertilization 5) Off springs are identical and same as parents. |
1) It involves two parents. 2) Male and female gametes are formed. 3) Gametic fusion occurs. 4) Fertilization takes place. 5) Variations occur in sexual reproduction. So off springs are not identical to that ofparents. |
In vegetative reproduction, offsprings are produced from a single parent. As it does not involve two parents, it is considered as a type of asexual reproduction.
Question 12.
Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n)
(a) Ovary.
(b) Anther
(c) Egg
(d) Pollen
(e) Male gamete
(f) Zygote
(g) Antipodal
(h) Megaspore mother cell
[AP M-18] [TS M-17]
Answer:
(a) Ovary -diploid(2n)
(b) Anther- diploid(2n)
(c) Egg- haploid(n)
(d) Pollen – haploid(n)
(e) Male gamete- haploid(n)
(f) Zygote- diploid(2n)
(g) Antipodal- haploid(n)
(h) Megaspore mother cell- diploid(2n)
Question 13.
Give a brief account on the phases of the life cycle of an angiosperm plant.
Answer:
The life cycle of angiospermic plant consists of two phases. [APM-19]
A) Sporophytic phase:
- It is diploid (2n).
- It is the dominant phase of the life cycle.
- It is developed from the zygote. Reproductive organs develop at this stage.
B) Gametophyte phase:
- It is haploid (n).
- It is derived from a spore which is a product of meiotic division of spore mother cell.
- In angiosperms, microspore mother cells and megaspore mother cells are present.
- The mega spore mother cells undergo reduction division and produces megaspores.
- With the production of microspores & mega spores, the sporophytic generation comes to an end.
- Micro and mega spores produce male and female gametophytes respectively.
- Male and female gametes formed respectively from male and female gametophytes fuse to form a diploid zygote.
- The zygote is the first cell of the sporophyte.
- The zygote undergoes repeated mitotic divisions to produce an embryo (2n) in the seed.
- The seed germinates and gives rise to a sporophytic plant body.
Long Answer Questions
Question 1.
Enumerate the differences between asexual and sexual reproduction. Describe the types of asexual reproduction exhibited by unicellular organisms.
Answer:
Differences between asexual and sexual reproduction:
Asexual reproduction
- It involves a single organism.
- There is no production of gametes.
- There is no fusion of gametes.
- It requires only mitotic division.
- This method produces off springs that are identical to the parent.
- Chance of genetic variation is only through random mutation.
- It is not very useful for natural selection and in evolution of species.
- It occurs by sporulation, fragmentation etc. Ex: Fungi, Algae, Bacteria.
Sexual reproduction
- It involves one or two organisms.
- Male and female gametes are present.
- Involves fusion of male and female gametes.
- It requires meiotic followed by mitotic divisions.
- In this method, offsprings will have some characters from male parent and other from female parent.
- There is more chance for genetic variation.
- It is highly useful for natural selection and in evolution of species.
- It occurs due to pollination and fertilization. Ex: Human beings, Insects, Monocots and dicots.
Unicellular organisms reproduce asexually by binary fission, budding and spore formation.
a) Binary fission: In this type the parent cell divides into two equal halves by mitosis and each one grows into new individuals. Ex: Bacteria, Amoeba etc.
b) Budding: In unicellular fungi like yeast, asexual reproduction occurs by budding. The division is unequal. Small buds are produced that remain attached initially to the parent cell, which eventually get separated and mature into new yeast organisms.
c) Sporulation: Asexual reproduction in chlamydomonas is by motile spore formation. As the spores are motile they are also known as zoo spores.
Question 2.
Although sexual reproduction is long drawn energy intensive complex form of repro- (friction, many groups of organisms in kingdom plantae prefer this mode of reproduction. Give atleast three reasons for this.
Answer:
Three reasons for many higher organisms to prefer sexual reproduction:
- The ‘sexual mode of reproduction’ ensures ‘creation of new varieties’ with hybrid vigour.
- Genetically varied offsprings are produced that adapt to changes in environment and survive in all climatic conditions.
- Sexual reproduction ensures genetic recombination which leads to evolution.
Sexual reproduction follows a regular sequence of A) Pre-fertilization B) Fertilization C)Post-fertilization A) Pre-fertilization events: These events include: (i) Gametogenesis (ii) Gamete transfer.
(i) Gametogenesis: It is the formation of male and female haploid gametes.
- In algae, gamete may be similar- Isogametes.
- In Pteris, cycas, gametes are dissimilar heterogametes.
- Gametes may be produced from unisexual or bisexual condition
- Gametes are formed by mitotic division incaseof monera, fungi, algae & bryophtes.
- In pteridophytes, gymnosperms & angiosperms gamete formation occurs through meiosis.
- After gametogenesis, male and female must be brought together for fertilization.
(ii) Gamete transfer:
- Male is motile & female stationary in majority forms.
- In algae fungi & pteridophytes, water is medium for gamete transfer.
- In seed plants, pollen grain are carriers of male gametes and pollination takes place to transfer pollen from anther to stigma (self pollination and cross pollination)
- Pollen tubes carry male gamete from stigma to female gamete in the ovule.
(B) Fertilisation: It is the vital event of sexual reproduction
- Process of fusion of male and female gametes is called syngamy or fertilisation.
- It results in the formation of diploid zygote from genetically dissimilar haploid gametes.
- Genetic recombinations takes place which results in variations with hybrid vigour.
- It leads to evolution.
Fertilization is of two types:
- External fertilization: It occurs outside the body of the organisms and in external medium (water) Ex: Algae
- Internal fertilization: It occurs in the body of organism Ex: Bryophytes, Angiosperms
(C) Post-fertilization events: These are the events which occur after formation of zygote.
- In algae & fungi with haplontic life cycle, zygote develops thick wall to resist adverse condi¬tions before germination. Later it divides by mitosis to grow into haploid individuals.
- Zygote divides to form embryo by mitosis.
- Embryogenesis: Development of embryo from zygote.
- Cell division and Cell differentiation of embryo takes place to form an organism
- In flowering plants, zygote is formed inside the ovule.
- Ovule turns into seeds.
- In angiosperms, ovary changes in the fruit seeds are inside the fruit.
- Seeds are naked and visible in gymnosperms.
Significance of Sexual Reproduction:
- It helps to survive during unfavourable conditions.
- It is responsible for genetic variation in offspring due to new gene combination.
- Formation of new varieties leads to organic evolution.
Question 3.
Describe the post-fertilisation changes in a flower.
Answer:
Changes in a flower after fertilisation:
- Calyx, Corolla, Stamens, style and stigma wither and drop away.
- Ovary becomes fruit.
- Ovules – seeds.
- Wall of the ovary – fruit wall (pericarp)
- Funiculus – stalk of the seed.
- Outer integument of ovule – Outer seed coat testa
- Inner integument of ovule – inner seed coat tegmen.
- Micropyle of ovule – Micropyle of seed
- Zygote – embryo
- Synergids – degenerate
- Antipodals – degenerate
- Raphe of ovule – Hilum (Scar of the seed)
- Endosperm – Nutritive tissue of embryo. Eg: Maize, Cocoa
- Calyx of Solanum – persistant and maerescent calyx
- Calyx of Tridax – Pappus which helps in fruit dispersal.
- Nucellus of ovule – nutrient tissue called perisperm in Nymphea, piper.
Exercise
Question 1.
Why is reproduction essential for organisms?
Answer:
- Reproduction enables a species to live generation after generation.
- Reproduction is a process in living organisms that ensures the continuity of the race.
- The process of reproduction enhances the population growth.
Question 2.
Which is a better mode of reproduction sexual or asexual? Why?
Answer:
- Sexual reproduction is the better mode of reproduction.
- Sexual reproduction brings diversity in the offsprings.
- It is responsible to adjust the new surroundings and develop immunity to resist the diseases.
Question 3.
Why is the offspring formed by asexual reproduction referred to as clone?
Answer:
- The offsprings produces during asexual reproduction does not involve two parents.
- The offsprings are identical. Hence they are called clones.
Question 4.
How does the progeny formed from asexual reproduction differ from those formed by sexual reproduction?
Answer:
- The progeny formed from asexual reproduction will have the same characters of the parent
with out any deviation, there is no possibility of getting genetic variation in them. Chances of evolution are meagre. - The progeny formed from sexual reproduction will have both the characters of parents and other additional characters also. They will have genetic variation. Chances of evolution are more.
Question 5.
What is vegetative propagation? Give two suitable examples.
Answer:
- Production of offsprings from vegetative parts of the plant body such as root, stem and leaf is called vegetative propagation.
- Ex: Bryophyllum, Murraya
Question 6.
Higher organisms have resorted to sexual reproduction inspite of its complexity’. Why?
Answer:
- Sexual reproduction brings variation in off springs.
- Chances of survival are more because they get immunity.
- They can adjust to varied environmental changes.
Question 7.
Explain why meiosis and gametogenesis are always interlinked?
Answer:
- Gametes are always haploid. Meiosis is the reduction division which produces meocytes.
- The meiocytes transform into gametes. Thus gametogenesis is linked with meiosis.
Question 8.
Define external fertilisation. Mention its disadvantages.
Answer:
- Fertilisation outside the body of the organism is called external fertilisation. In majority of aquatic organisms like algae and some fishes external fertilisation occurs.
- For that purpose the parents have to produce and release large number of gametes as the chances of fusion and syngamy are low.
Question 9.
Differentiate between a zoospore and a zygote.
Answer:
Question 10.
Examine a few flowers of any cucurbit plant and try to identify the staminate and pistillate flowers. Do you know any other plant that bears unisexual flowers?
Answer:
- Cucurbit plant is monoecious. Male and female flowers occur on the same plant. Male flowers
are identified by the presence of stamens and female flowers by the presence of gynoecium. - In cocos also male and female flowers are borne on the same plant.
- In Borassus male and female flowers are borne on different plants. So the plant is dioecious.
Question 11.
What is bisexual flower? Collect five bisexual flowers from your neighbour hood and dr common and scientific names.
Answer:
- When a flower has both androecium and gynoecium, the flower is said to be bisexual.
- The student has to collect five bisexual flowers and observe the features with the help of his teacher.
Multiple Choice Questions
Question 1.
All organisms begin their life from a single cell, called
1. Male gamete
2. Female gamete
3. Microspore
4. Zygote
Answer:
4. Zygote
Question 2.
Bisexual condition in fungi Are described as
1. Homothallism
2. Heterothallism
3. Dioecious condition
4. Isogamy
Answer:
1. Homothallism
Question 3.
Cladophora produces
1. Homogametes
2. Anisogametes
3. Heterogametes
4. Oogametes
Answer:
1. Homogametes
Question 4.
Diploid structure in the embryo sac is
1. Secondaiy nucleus
2. Egg apparatus
3. Antipodal cells
4. Synergids
Answer:
1. Secondaiy nucleus
Question 5.
Eukaryotic organisms which reproduce by binary lisslon are
1) Yeast
2) Euglena
3) Bacteria
4) Fungi
Answer:
2) Euglena
Question 6.
Fragmentation mode of vegetative reproduction occurs by
1. The formation of zoospores
2. The formation ofconidia
3. The formation of spores
4. The split/break of the vegetative body
Answer:
4. The split/break of the vegetative body
Question 7.
Female gametophyte of angiosperms Is called
1) Embryo
2) Ovum
3) Egg
4) Embryòsac
Answer:
4) Embryòsac
Question 8.
Highlý reduced gametophyte is found in
1) Bryophytes
2) Pteridophytes
3) Gymnosperms
4) Angiosperms
Answer:
4) Angiosperms
Question 9.
Type of life cycle In anglosperms Is
1) Haplo-diplontic
2) Diplo-haplontic
3) Diplontic
4) Haplontic
Answer:
3) Diplontic
Question 10.
Plants that are produced vegetatively or asexually are called
1. Hybrids
2. Clones
3. Mutants
4. Variants
Answer:
2. Clones
Question 11.
Vegetative reproduction occurs through gemmac in
1. Angiosperms
2. Gymnosperms
3. Liverworts
4. Pteridophytes
Answer:
3. Liverworts
Question 12.
The scourge of water bodies or ‘Terror of Bengal’ Is
1. Water hyacinth
2. Pistia
3. Hydrifla
4. Vallisneria
Answer:
1. Water hyacinth
Question 13.
In seed plants, the male gametes arc carried to the egg by
1.Water
2.Wind
3. Insects
4. Pollen tube
Answer:
4. Pollen tube
Question 14.
MIcroscopic angiospermic plant belongs to the genus
1.Wolffia
2. Eucalyptus
3. Agave
4. Sequoia
Answer:
1.Wolffia
Question 15.
Asexual reproduction occurs by budding in
1. Cladophora
2. Rhizopus
3. Penicillium
4. Yeast
Answer:
4. Yeast
Question 16.
Number of chromosomes found in the endosperm cell of rice Is
1) 24
2) 12
3) 36
4) 48
Answer:
3) 36
Question 17.
Number of nuclei involved in double fertilisation are
1. Two
2.Three
3. Five
4. Six
Answer:
3. Five
Question 18.
Both male and female gametes are motile in
1. few fungi and algae
2. Gymnosperms
3. Angiosperms
4. Spermatophytes
Answer:
1. few fungi and algae
Question 19.
The scientific name of century plant is
1. Strobilanthus kunthiana
2. Smilax zeylanica
3. Agave americana
4. Dracaena angustifolia
Answer:
3. Agave americana
Question 20.
Neelakuranji plant flowers during the months of
1. January-February
2. September-October
3. November-December
4. June-July
Answer:
1. January-February
Question 21.
The mangrove plant producing pneumatophores shows
1. Vivipary
2. Parthonogenesis
3. Extemal fertilisation
4. Isogamy
Answer:
1. Vivipary
Question 22.
The type of gametes produced by Fucus are
1. Homogametes
2. Isogametes
3. Heterogametes
4. Oogametes
Answer:
3. Heterogametes
Question 23.
Swarm spores are
1. Non-motile spores of Rhizopus
2. Non-motile spores of Penicillium
3. Zoospores of Chiamydomonas
4. Non-motile spores of Pteridophytes
Answer:
3. Zoospores of Chiamydomonas
Question 24.
Angiospermic plant body refers to
1. Primary structures only
2. Gametophytes only
3. Sporophyte only
4. Only the aerial part of the plant
Answer:
3. Sporophyte only
Question 25.
P. Maheswari popularized the use of ………… characters in planttuxonomy
1) Anatomical
2) Embryological
3) Invitro tissue culture
4) Morphological
Answer:
2) Embryological
Question 26.
Cell division is itself a type of reproduction in
1) Euglena
2) Penciliuin
3) Rhizopus
4) Liver worts
Answer:
1) Euglena
Question 27.
Bacteria and yeas( reproduce asexually by binary fission and budding respectively, because 1hc are
1) Microscopic organisms
2) Uninucleated organisms
3) Unicellular organisms
4) Heterotropic organisms
Answer:
3) Unicellular organisms
Question 28.
Number of parents involved in asexual and sexual reproductions respectively
1) 2,1
2) 1,2
3) 2,2
4) 1,1
Answer:
1) 2,1
Question 29.
The sequence events occurs during the entire lifespan of living organism
1) Juvenile phase-Mature phase-Old age -Death
2) Mature phase-Juvenile phase-Old age-Death
3) Old age-Mature phase-Juvenile phase-Death
4) Juvenile phase-Old age-Mature phase-Death
Answer:
1) Juvenile phase-Mature phase-Old age -Death
Question 30.
Oogonium and archegonium are the female sex organs (gameiangia) respectively in
1) Chara and Marchantia
2) Maize and carica
3) Papaya and date palm
4) Marchantia and Fucus
Answer:
1) Chara and Marchantia
Question 31.
Male and female sex organs develop on different growing stalk-like structures of plant which bears rhizoids.
1) Papaya
2) Date palm
3) Marchantia
4) Chara
Answer:
3) Marchantia
Question 32.
Development of an embryo from an unfertilized female gamete is known as
1) Amphimixis
2) Syngamy
3) Parthenogenesis
4) Polyembryony
Answer:
3) Parthenogenesis
Question 33.
Male gametes produced by the organisms exhibits internal fertilization which is
1) always motile
2) always non-motile
3) motileornon-motile
4) fixed
Answer:
3) motileornon-motile
Question 34.
In seed plants, male gametes are carried to the vicinity of female gamete by
1) external water
2) pollen tube
3) insects
4) wind
Answer:
2) pollen tube
Question 35.
Thick walled resistant zygote can be produced in the life cycle of these plants
1) Bryophytes
2) Pteridophytes
3) Thallophytes
4) Gymnosperms
Answer:
3) Thallophytes
Question 36.
Clone is a group of individuals which got through
1) Self pollination
2) Cross pollination
3) Vegetative propagation
4) Hybridization
Answer:
3) Vegetative propagation
Question 37.
The vital link that ensures continuity of species between organisms of one generation and the next is
1) Seed
2) Egg
3) Spore
4) Zygote
Answer:
4) Zygote
Question 38.
A bacterial cell divides every 20 minutes by binary fission. How’ much time is taken to produce 256 cells from one cell?
1) 2 hours
2) 3 hours
3) 2 hours 40 minutes
4) 1 hour 20 minutes
Answer:
3) 2 hours 40 minutes
Question 39.
Roth sporophyte and gametophyte are dioecious in
1) Zea mays
2) Carica papaya
3) Pinus
4) Colocasia
Answer:
2) Carica papaya
Question 40.
Study the following
a) Production of offspring by a single parent is always asexual reproduction.
b) Gametes are not formed in organisms which reproduce asexually.
1) a and b are true
2) a is true, b is false
3) a and b are false
4) a is false, b is true
Answer:
3) a and b are false
Question 41.
Advantage of having ’spore’ as a asexual reproductive unit is
a) They are adapted for disperssal
b) They are produced by meiosis
c) They can survive long periods of unfavorable conditions.
1) a and b
2) b and c
3) a, band c
4) a and c
Answer:
4) a and c
Question 42.
A feature unique to angiosperms is
a) Triple fusion
b) Syngamy
c) Fertilization involving pollen tube
d) Fertilition proceded by pollination
1) a and c
2) a only
3) c and d
4) a, c and d
Answer:
2) a only