Objective Question
1.The edible part of mango fruit is –
(A) outer fruit wall
(B) middle fruit wall
(C) Endofruit wall
(D) None of these
Answer ⇒ (B)
2. Mitosis occurs.
(A) in somatic cell
(B) In the reproductive cell
(C) In both (A) and (B)
(D) None of these
Answer: (A)
3. The process of forming fruits without fertilization is called
(A) Polycarpic
(B) Parthenocarpic
(C) Pomocarpic
(D) None of these
Answer ⇒ (B)
4. Which of the following does not have internal fertilization?
(A) bird
(B) Frog
(C) Mammal
(D) None of these
Answer ⇒ (B)
5. A type of dichotomy
(A) vegetative propagation
(B) Asexual reproduction is
(C) Sexual reproduction is
(D) None of these
Answer ⇒ (B)
6. Which of these is an egg?
(A) Echidna
(B) Kangaroo
(C) Cow
(D) None of these
Answer: (A)
7. These flower only once in their entire life.
(A) Bamboo
(B) Mango
(C) Palm
(D) None of these
Answer: (A)
8. Which of the following is diploid?
(A) Pollen
(B) egg
(C) (A) and (B)
(D) Zygote
Answer: (D)
9. The seeds of which fruit are eaten?
(A) Custard apple
(B) Litchi
(C) Nutmeg
(D) All of these
Answer: (D)
10. Homozygous is found in :
(A) Algae
(B) Angiosperms
(C) Gymnosperm
(D) All of these
Answer: (A)
11. Who among the following is the egg producer?
(A) snake
(B) Crocodile
(C) Hen
(D) All of these
Answer: (D)
12. Which of the following is a true result?
(A) Apple
(B) Pear
(C) Kajula
(D) Coconut
Answer: (D)
13. In what does reproduction take place through ‘budding’?
(A) Penicillium
(B) Paramecium
(C) Yeast
(D) All of these
Answer: (C)
14.Which of the following is a false result:
(A) Apple
(B) Mango
(C) Banana
(D) None of these
Answer: (A)
15. In which of these is dichroism found:
(A) Water hyacinth
(B) Lotus
(C) Amoeba
(D) snake
Answer: (C)
16. Gemules are formed
(A) In Hydra
(B) In sponge
(C) In the East
(D) All of these
Answer ⇒ (B)
17. The edible part of litchi is called?
(A) Tegmen
(B) Endosperm
(C) integument
(D) Beej Chola
Answer: (D)
18. What is fruit formation without fertilization called?
(A) decoupled matter
(B) Disjunction
(C) Parthenogenesis
(D) All of these
Answer: (C)
19. Choose the correct one among the following:
(A) Zoospore of sponge
(B) Gymulus in Penicillium
(C) Conidia in algae
(D) Bud of Hydra
Answer: (D)
20. Grafting cannot take place in sugarcane because
(A) Vascular bundles are scattered.
(B) Phloem is on the inside of xylem.
(C) Reed plants are delicate.
(D) It is unable to bear injury.
Answer: (A)
21.For what is sexual reproduction responsible?
(A) To form the diploid state
(B) To create identical young ones
(C) No role in evolution
(D) To create haploid state
Answer: (A)
22. Mint propagates vegetatively :
(A) sucker
(B) Runner
(C) offset
(D) rhizome
Answer: (A)
23. Possible life span of a dog…….… It happens.
(A) 20 years
(B) 15 years
(C) 10 years
(D) 5 years
Answer: (A)
24. The scion is planted on the stock. On what will the fruits of a tree grafted in this way depend?
(A) scion
(B) Stock
(C) (A), (B) both
(D) None of the above
Answer: (A)
25. The process of fusion of haploid cells is called ………. They say.
(A) cell cycle
(B) Meiosis
(C) Mitosis
(D) conjugation
Answer: (D)
26.…………. Vegetative reproduction occurs by segments of leaves in?
(A) Agave and Kalanchoe
(B) Biofilm and Kalanchoe
(C) Asparagus and Bryophyllum
(D) Chrysanthemum and Agave
Answer ⇒ (B)
27. Flowers that bloom at night generally…………
(A) are light
(B) are smaller
(C) are brightly colored
(D) bloom in clusters
Answer ⇒ (B)
28. Hermaphrodite animal is:
(A) Hen
(B) snake
(C) Both (A) and (B)
(D) Earthworm
Answer: (D)
29. Which of the following is a diploid structure?
(A) Egg
(B) Sperm
(C) Zygote
(D) All of these
Answer: (C)
30. The state between birth and natural death is called:
(A) life span
(B) Life cycle
(C) vegetative state
(D) all
Answer: (A)
31. Morphologically and genetically similar organisms are called:
(A) clone
(B) Somaclone
(C) Cosmids
(D) Cybrids
Answer: (A)
32. How does reproduction take place in amoeba?
(A) Conidia
(B) bud
(C) Jimmules
(D) By binary fission
Answer: (D)
33. Reproduction occurs in Penicillium:
(A) bud
(B) fragmentation
(C) Jimules
(D) Conidia
Answer: (D)
34. What is the menstrual cycle?
(A) Monkey
(B) Ape
(C) Human
(D) all
Answer: (D)
35. Which of the following does not have oestrous cycle?
(A) Cow
(B) Sheep
(C) Monkey’s
(D) dog
Answer: (C)
36. Who among the following is not hermaphrodite?
(A) Tapeworm
(B) dog
(C) Leech
(D) Sponge
Answer ⇒ (B)
37. In which of the following water is not required for gamete transfer?
(A) Algae Chicago
(B) Bryophytes got done
(C) Pteridophytes
(D) Gymnosperm
Answer: (D)
38. The process of embryo development is called:
(A) viviparyo
(B) Parthenogenesis
(C) embryogenesis
(D) Sporogenesis
Answer: (C)
39. Accumulation of gametes is called:
(A) Pollination
(B) Syngamy someone
(C) Parthenogenesis
(D) Sporogenesis
Answer ⇒ (B)
40. Who among these is not homosexual?
(A) Cockroach
(B) dog
(C) Cow
(D) Earthworm
Answer: (D)
41. The number of chromosomes in human gamete is :
(A) 21
(B) 23
(C) 44
(D) 46
Answer ⇒ (B)
42. What involves internal fertilization?
(A) Fish
(B) Amphibians
(C) Algae
(D) Angiosperms
Answer: (D)
43. In the process of fertilization, the ovule develops and forms a seed, while what develops from the carpel?
(A) Peri sperm
(B) Pericarp
(C) Testa
(D) None of these
Answer ⇒ (B)
44. Which of the following is not an egg:
(A) snake
(B) Hen
(C) Alligator
(D) human
Answer: (D)
45. Which of these flowers blooms only once in its lifetime?
(A) Bamboo
(B) Mango
(C) Litchi
(D) Berries
Answer: (A)
46. In which of the following flowers bloom only once in 12 years?
(A) Sunflower
(B) Peepal
(C) Blue Kurenji
(D) Neem
Answer: (C)
47. An example of rhizome is:
(A) Garlic
(B) Lemon
(C) Ginger
(D) Onion
Answer: (C)
48. Bud planting is an example of :
(A) vegetative reproduction
(B) Tissue culture
(C) Sexual reproduction.
(D) of scattering
Answer: (A)
49. In the fungus named Penicillium, asexual reproduction mainly occurs through which structure?
(A) Budding
(B) fragmentation
(C) Conidia
(D) Gemulus
Answer: (C)
50. Which of these grows in stagnant water and extracts oxygen?
(A) Water hyacinth
(B) Hydrilla
(C) Lotus
(D) Paddy
Answer: (A)
51. Reproduction occurs by Gemma: –
(A) In higher order plants
(B) Direction in lower order animals
(C) In some bryophyta
(D) In mammals
Answer: (C)
52. Which word is used to describe the condition of monogamy?
(A) Homozygous
(B) Hermaphroditic
(C) Monogamous
(D) subjective couplet
Answer: (C)
53. The result of double fertilization is:
(A) Cotyledons
(B) Nucleolus
(C) Endosperm
(D) embryo
Answer: (C)
54. In which group are plants reproducing by spores like mosses and ferns generally kept?
(A) Sporophytes
(B) Thallophytes
(C) Cryptogames
(D) Biophytes
Answer: (C)
55. Pollination occurs in Cycas:
(A) In three cellular state
(B) In four cellular state
(C) In two cellular state
(D) in unicellular state
Answer: (A)
56. The phenomenon of anthesis is based on
(A) Pollen formation
(B) Pollen grain reaching the stigma
(C) Development of anther
(D) Opening of flower bud
Answer: (D)
57. Which of the following reproduces through the tip of the leaf?
(A) Walking Fern
(B) Sprout leaf plant
(C) Marchesia
(D) meat
Answer: (A)
58. Potato tubers have eyes:
(A) Flower buds
(B) shoot buds
(C) axillary buds
(D) root buds
Answer: (C)
59. Which of the following plants is hermaphroditic?
(A) Marchenia
(B) Pinus
(C) Cycas
(D) Papaya
Answer ⇒ (B)
60. Who among the following is monogamous?
(A) Mustard
(B) Udhul
(C) Papaya
(D) None of these
Answer: (C)
61. The method of formation of egg is called:
(A) Eggogenesis
(B) Ovary
(C) Ovulation
(D) female reproduction
Answer: (A)
62. The mechanism of sperm formation is called:
(A) Spermatogenesis
(B) Female reproduction
(C) Gametogenesis
(D) organogenesis
Answer: (A)
63. How many organisms take part in asexual reproduction?
(A) one
(B) two
(C) three
(D) Not even one
Answer: (A)
64. Asexual reproduction can occur in plants by which of the following methods?
(A) Budding
(B) fragmentation
(C) Partition
(D) all
Answer: (A)
65. In which of the following ways does vegetative reproduction occur?
(A) root
(B) Pillar
(C) leaf
(D) by all three
Answer: (D)
66. By what means does vegetative transmission take place in potato?
(A) Leaves
(B) Pillar
(C) root
(D) seeds
Answer ⇒ (B)
67. What is the arrival of pollen grains from anthers within the same fruit into the ovary called?
(A) Self pollination
(B) Ovulation
(C) cross pollination
(D) fertilization
Answer: (A)
68. What is the process of release of egg from the ovary called?
(A) Eggogenesis
(B) Ovulation
(C) Menstrual cycle
(D) Spermatogenesis
Answer ⇒ (B)
69. Where does fertilization of the egg take place in the human female?
(A) in the ovary
(B) in the uterus
(C) work in the vagina
(D) in the fallopian tube
Answer: (D)
70. In which reproductive organ is sperm stored in human male?
(A) penis
(B) vas deferens
(C) Epididymis
(D) testicles
Answer: (C)
71. Gamete contains set of chromosomes:
(A) 2n
(B) 3n
(C) 4n
(D) n
Answer: (D)
72. How many parents take part in the creation of living organisms in asexual reproduction?
(A) one
(B) two
(C) three
(D) four
Answer: (A)
73. What is formed by the fusion of the gamete given by the mother and the gamete given by the father?
(A) coupler
(B) Zygote
(C) Offspring
(D) gills
Answer ⇒ (B)
74. The process by which male gametes and female gametes are formed is called:
(A) fertilization
(B) Embryogenesis
(C) Gametogenesis
(D) Morphogenesis
Answer: (C)
75. The three-layered structure inside which a new cavity has formed is called Archenteron.
(A) Blastula
(B) Gastula queen
(C) Cleavage
(D) None of these
Answer ⇒ (B)
76. The organism or plant in whose body both male and female reproductive types are found is called:
(A) Spore
(B) Conjugation
(C) Bisexual
(D) monogamous
Answer: (C)
77. More variations are seen in which type of reproducing creatures?
(A) Sexual reproduction
(B) Asexual reproduction
(C) Gametogenesis
(D) vegetative
Answer: (A)
78. The process under which an organism continuously maintains its species by giving birth to identical children is called:
(A) Reproduction
(B) Sexual reproduction
(C) Asexual reproduction
(D) Gametogenesis
Answer: (A)
79. Animals, which give birth to babies, are called:
(A) egg
(B) uterus
(C) Amphibians (B)
(D) Bisexual
Answer ⇒ (B)
80. The entire process of development from egg to adult is called:
(A) Conception
(B) fertilization
(C) Addition
(D) Cleavage
Answer: (A)
81. Plasmotomy occurs in
(A) Hydra
(B) Obelia
(C) Opalina
(D) Plasmodium
Answer ⇒ (C and D)
82. The development of a seed from an unfertilized egg is called:
(A) Viviparous
(B) Parthenocopy
(C) Apogamy
(D) Apospory
Answer ⇒ (B)
83. Grafting is rarely successful in monocotyledons because :
(A) Monocotyledons have closed vascular bundles.
(B) Monocotyledons are cambiumless
(C) There is parallel venation
(D) More than one is correct
Answer ⇒ (B)
84. Aphyra larva is found in Aurelia. By what method is it manufactured?
(A) Regeneration
(B) Fragmentation
(C) breakage
(D) Strobilation
Answer: (D)
85. What is studied in gerontology?
(A) bird
(B) Bone
(C) Aging
(D) Earth
Answer: (C)
86. Which of the following has the ability to reproduce without fertilization?
(A) Spider
(B) Cow
(C) Bee
(D) Earthworm
Answer: (C)
87. The number of chromosomes in onion gametes is:
(A) 8
(B) 16
(C) 24
(D) 32
Answer ⇒ (B)
88. Endosperm in any gymnosperm is:
(A) haploid
(B) diploid
(C) Triple
(D) Quadruple
Answer: (C)
89. The ovaries of a flower are:
(A) haploid
(B) diploid
(C) Triple
(D) Quadruple
Answer ⇒ (B)
90. Where does meiosis occur in plants?
(A) root end
(B) Pollen
(C) ends of the stem
(D) anther
Answer: (D)
91. Construction of a complete body from a small part/piece is called:
(A) Morphallaxis
(B) epimorphosis
(C) Morphogenesis
(D) Metabolism
Answer: (A)
92. In what is double fertilization found?
(A) Angiosperms
(B) Gymnosperm
(C) Pteridophytes
(D) Bryophytes
Answer: (A)
94. By what means vegetative propagation takes place in Pistia?
(A) Stallone
(B) offset
(C) Runner
(D) Sucker
Answer ⇒ (B)
95. The number of chromosomes in meiocytes of house fly is :
(A) 8
(B) 12
(C) 34
(D) 21
Answer ⇒ (B)
96. In which of the following animals ovo-biparity occurs?
(A) Hen
(B) Platypus
(C) Rattle snake
(D) Echidna
Answer: (C)
97. Parthenogenesis is found in:
(A) In axolotl larva
(B) In Miracidium
(C) In cercaria
(D) In sporocyst and redia larva
Answer: (D)
98. If the male is different from the female in morphology, then it is called:
(A) Heterogamy
(B) Homogamy
(C) Sexual dimorphism
(D) Hermaphroditism
Answer: (C)
99. Paedogenesis is found in which larva?
(A) Tinea
(B) Fasciola
(C) Rana
(D) butterfly
Answer ⇒ (B)
100. In what is oblique dichroism found?
(A) Monocystis
(B) Plasmodium
(C) Planaria
(D) Ceratium
Answer: (D)
101. After puberty in animals comes:
(A) vegetative state
(B) Reproductive stage
(C) adulthood
(D) old age
Answer ⇒ (B)
102. Which of the following is the correct order?
(A) Gametogenesis – Conjugation – Embryogenesis – Zygote
(B) Conjugation – Gametogenesis – Zygote – Embryogenesis Hero
(C) Gametogenesis – Conjugation – Zygote – Embryo production
(D) Zygote – Embryogenesis – Conjugation – Gametogenesis
Answer: (C)
103. What are the words Homothallic and Monoecious used for?
(A) For hermaphrodite state
(B) For unisexual state
(C) For staminate flowers
(D) For pistillate flowers
Answer: (A)
104. What is the oldest age of a parrot?
(A) 90 years
(B) 25 years
(C) 500 years
(D) 140 years
Answer: (D)
105.Which of the following plants is dioecious?
(A) Papaya
(B) Dates
(C) Coconut
(D) Any two of these
Answer: (C)
106.Which is a hermaphrodite animal?
(A) Earthworm, Hydra and Leech
(B) Cockroach, Ascaris and Hydra
(C) Earthworm, Ascaris and leech
(D) Ascaris, cockroach and hydra
Answer: (A)
107.Haploid chromosome is found in which?
(A) Zygote
(B) Coupler
(C) embryo
(D) seeds
Answer ⇒ (B)
108. How many gametes are there in the pollen tube in angiosperms?
(A) one
(B) two
(C) three
(D) many
Answer ⇒ (B)
109. In which situation is the word Dioecious used?
(A) Bisexual
(B) monogamous
(C) Bisexual
(D) Gynandromorph
Answer ⇒ (B)
110. Flowering occurs in bamboo species.
(A) Once in a lifetime
(B) Once in 12 years
(C) Every year
(D) Twice in 50-100 years
Answer: (A)
111. The number of chromosomes in the meiocyte of Drosophila (Fruit fly) is:
(A) 2
(B) 4
(C) 6
(D) 8
Answer: (D)
112.The lifespan of crocodile and may fly is respectively
(A) 15 years 1 week
(B) 30 years, 1 week
(C) 45 years, 1 month
(D) 60 years, 1 day
Answer: (D)
113.Nodes are called ‘eyes’ which form a new plant in which of the following?
(A) Ginger
(B) Bryophyllum
(C) Alocasia
(D) Potato
Answer: (D)
114.Motile ciliated spore is called:
(A) Aplanospores
(B) Conidia
(C) Zoospores
(D) Uspores
Answer: (C)
115. If two gametes look similar, then it is said:
(A) Isogametes
(B) Heterogametes
(C) Anisogametes
(D) Exogamy
Answer: (A)
116.The number of chromosomes in human meiosis cell (Melcyte) is:
(A) 40
(B) 42
(C) 44
(D) 46
Answer: (D)
117.No creature is immortal except an alien.
(A) unicellular organism
(B) Green plants
(C) Spose
(D) Cyanobacteria
Answer: (A)
118.Children who are almost identical to each other and are also identical to their parents are called:
(A) Twins
(B) makes copies
(C) Drones
(D) clone
Answer: (D)
119.The formation of gametes is called:
(A) Gametogenesis
(B) Cytokinesis
(C) Sporogenesis
(D) myocyte
Answer: (A)
120.Which of the following is not a hermaphroditic plant?
(A) Papaya
(B) Mustard
(C) Maize
(D) Udhul
Answer: (A)
121.What is it called when the offspring is produced from a single parent?
(A) Sexual reproduction
(B) Asexual reproduction
(C) Both (A) and (B)
(D) internal fertilization
Answer ⇒ (B)
122.Eggs
(A) Hen
(B) snake
(C) Crocodile
(D) All of these
Answer: (D)
123. is diploid
(A) egg
(B) Pollen
(C) Both (A) and (B)
(D) Zygote
Answer: (D)
124.Which of the following animals is not hermaphrodite?
(A) Tapeworm
(B) Earthworm
(C) House fly
(D) Leech
Answer: (C)
125. Which of the following is Acetabularia?
(A) single cell protein
(B) Algae
(C) Protozoa
(D) bacteria
Answer ⇒ (B)
126. In which of the following plant species, seeds are produced through apogenesis?
(A) Asteraceae and grass
(C) Citrus and mango
(B) Mustard
(D) None of these
Answer: (A)
127. Which of these has been called the ‘terror of Bengal’
(A) Agave
(B) Water hyacinth
(C) Banana
(D) Bryophyllum
Answer ⇒ (B)
128. Estrus cycles are found in
(A) Cow
(B) sheep
(C) Dog
(D) All of these
Answer: (D)
129. Bulb is an example of:
(A) Ginger
(B) Doob grass
(C) Onion
(D) Potato
Answer: (C)
130. Where does fertilization take place in mammals:
(A) Ovary
(B) resident part
(C) uterus
(D) Fallopian tube
Answer: (D)
131.Natural parthenogenesis is found in
(A) fly
(B) In bee
(C) Mosquito
(D) All of these
Answer ⇒ (B)
Short Answer Questions
Question 1. What is called reproduction?
Answer:- The process in which an organism produces another organism similar to itself is called reproduction.
Question 2. How many types of reproduction are there?
Answer :-
1.Sexual reproduction and
2.Asexual reproduction.
Question 3. Write a note on Mukulan.
Answer: Budding – This type of division is found in yeast and some bacteria. In this process, the cell grows externally and forms one or more small structures and the nucleus gets divided into two parts by mitosis (according to Lindgreen, 1949). According to some scientists, this division of the nucleus is of the type of amitosis or amitosis. Each bud separates from the mother cell and transforms into a new yeast cell. This process is called budding. When these outgrowths do not separate from their mother cell, they form chains, which are called pseudomycelium. But in the end they get separated.
Question 4. Write the names of two methods of artificial vegetative propagation.
Answer :-
1.penning
2. pressure pen
Question 5. How many methods of reproduction are found in plants? Describe each briefly.
Answer :- Methods of reproduction in plants
Mainly following two methods of reproduction are found in plants –
1. Asexual Reproduction – This is a common type of reproduction in which only one organism or parent takes part. In this method, after becoming an adult, the organism produces its offspring in the form of identical copies. Therefore, there is no difference in the genetic material and traits between the parents and the offspring. That is why the offspring produced as a result of asexual reproduction are called clones. Such reproduction occurs at a relatively rapid rate. There are no specific tissues or organs in the body for this.
2. Sexual Reproduction – The process of sexual reproduction is complex. For this, there are special types of reproductive organs in the body. The basic process of sexual reproduction is the conjugation of two different types of haploid (n) cells from the normal somatic cells of the body. These haploid cells are called sex cells or gametes. The somatic cells of the body are diploid. Sex cells are formed by a special type of meiotic or meiotic division in the germ cells of the major gonads. This process of their formation is called gametogenesis.
The two sex cells taking part in conjugation are of different types – one male gamete cell and the other female gamete cell. The diploid cell formed by their conjugation is called zygote. This is the beginning of a new child. In the gamete cells formed by meiosis of the reproductive cells, the distribution of paired homologous chromosomes of the reproductive cells is irregular and random. Then, in the formation of zygotes, the conjugation of male and female gametes also occurs coincidentally. Due to this, the genotypes of the zygotes are somewhat different from the genotypes of the reproductive cells. For this reason, the offspring formed as a result of sexual reproduction appear slightly different from the parents.
Question 6. Write a note on – Annual reproduction in bryophytes.
Answer :- Many types of annual reproduction take place in the gametophyte of bryophytes. For example – by Vikhandan, Gema, Kande, Puntantu, Patra-Process. In the fission method, the body of the multicellular parent plant disintegrates into two or more pieces and each piece develops into a new adult offspring through regeneration. Sometimes, multicellular and green colored formations appear on the front part of the leaves and stem of the plant, which are called gemules. These separate and give birth to a new plant by germination. Tubers and stem of plants also give birth to new plants. In bryophytes, uniform reproduction also takes place by leaf processes. Those buds in which food material is stored are called leaf processes. These buds break from the mother plant and fall to the ground. And in favorable weather, adventitious roots emerge which absorb water and mineral salts from the soil and the processes grow to form new plants.
Question 7. Write a note on micro propagation.
OR Write a short note on tissue culture.
Answer :- This is the most modern method of vegetative propagation. In this method, thousands of plants can be obtained from a little tissue of the mother plant. This method is based on tissue and cell culture technique.
In this method, a small portion of tissue is separated from some part of the plant from which propagation is to be done. Now this tissue is grown in an appropriate culture medium in aseptic conditions. This tissue grows by absorbing nutrients, forming clumps of cells called calluses. This callus can be preserved for a long time for multiplication. When required, a small piece of callus is transferred to another medium where it grows and develops into a small plant. This plant is taken out and planted in the soil. In this method.
Question 8. What is vegetative reproduction? How many types are there? Describe natural vegetative propagation in detail.
Or write a note on natural vegetative propagation.
OR Write a short note on vegetative reproduction in plants.
Answer :- Vegetative reproduction in plants
Vegetative reproduction is the process of reproduction or regeneration of a new plant. In this process, a new plant is formed from any vegetative part of the mother plant. All its symptoms and properties are similar to the mother plant. Vegetative reproduction is also known as vegetative propagation.
The formation of new plants by the vegetative parts of the mother plant is called vegetative reproduction or vegetative propagation.
This process is commonly seen in lower plants whereas in higher plants it occurs only in the following two ways –
1.Natural vegetative propagation
2. Artificial vegetative propagation
Natural vegetative propagation:-
This action is found in nature. Under this process, any organ or modified part of the plant separates from the mother plant and forms a new plant. This action takes place under favorable circumstances. Vegetative part of a plant; Like roots, stem and leaves take part in this process. These parts are modified in such a way that they can germinate and form a new plant. Various natural vegetative propagation methods are as follows:
(A) Underground stem :-
The main part or some part of the stem grows underground and gets transformed into a kind of food storage organ. But on it, axillary buds are found from which a new plant develops or branches emerge which come out of the soil and form a new plant. For example –
(i) Tuber – Growth is uneven (diffuse) Like – potato. The eye is found on this, in which the axillary bud is covered with scale leaves. This axillary bud germinates at a favorable time and forms a new plant. Definite festival treaties are not found.
(ii) Rhizome – This underground stem grows parallel or horizontal within the soil. Internodes and nodes meet on this. The festivals are condensed. The nodes are covered with scales in which the axillary bud is found. New plants emerge from these axillary buds; Like ginger, turmeric etc.
(iii) Corm – This underground stem grows vertically in the soil. In this, buds are covered with scales at the nodes from which a new plant is formed; Like – Colocasia, Saffron (Crocus), Jimikand (Amorphophallus) etc.
(iv) Bulb – This is the modification of the shoot where the stem is short and it gets juicy pulpy scales around the parallel stem. There are axillary buds in the cells of scale leaves which give birth to a new plant; Like – Onion (Allium cepa), Tulip, Tuberose (Narcissus) etc.
(B) Semiaerobic stem :-
This stem grows horizontally parallel to the ground. Roots and shoots (branches) emerge from each node. Sometimes some part of the compound is found in soil or water. For example –
(i) Runner – This stem is immersed and meets the outside of the soil horizontally. Roots emerge from each node and a shoot (branch) emerges which grows in the opposite direction. Each branch emerging from the node forms a new plant; Like Cyanodon, Oxalis, Centella etc.
(ii) Stolon – In these, roots and aerial parts emerge from the nodes. When the stem breaks, each aerial branch becomes an independent plant; Example – Arvi, Banana etc.
(iii) Offset – Being hydrophilous, their joints are submerged in water. From each node a group of leaves (tuft) emerges, below which is a bundle of roots which separate from the mother plant and form a new plant; Like – water hyacinth, Pistia etc.
(iv) Sucker – The main stem grows horizontally within the soil. Branches emerge from the soil at each joint; Like mint
(C) Origin
The roots of some plants propagate vegetatively; For example, in sweet potato (Ipomoea batatas), Satavar, Dahelia, Yam (Dioscored) etc., adventitious buds emerge which form a new plant. The roots of some woody plants; For example, shoots emerge from Muraya, Albuzia, Dalbergia etc. Which grows as a new plant.
(D) leaf
Vegetative propagation by leaves is generally less common. some plants; For example, in Bryophyllum and Kalanchoe, leaf buds are formed on the leaf margins from which small plants develop. In Begonia or Elephant Ear plant, leaf buds emerge on the petiole and veins etc. and on the entire surface.
(E) Nightingale
These processes are vegetative propagating reproductive organs. In Globba bulbifera, some flowers in the lower part of the inflorescence form bulbils or processes which are modified multicellular structures. Processes are also found in Onion (Allium cepg), American Aloe (Agave) etc. which are formed by the transformation of many flowers. processes
Question 9. Why is reproduction essential for living organisms?
Answer :-
Reproduction is a very important characteristic of living organisms. This is an essential biological process. Which not only helps in the survival of living beings but also maintains the continuity of the species. Reproduction also helps in the immortality of living beings. The loss of life due to natural death, old age and senescence is compensated for by reproduction only. The number of living beings increases through birth. Reproduction is a means by which beneficial variations are transferred from one generation to the next. Hence, reproduction also helps in biological development. On the basis of all these reasons, it can be said that reproduction is essential for living organisms.
Question 10. Which is the good method of reproduction and why?
Answer:- Generally sexual reproduction is considered to be the best method of reproduction. During sexual reproduction, chromosomes are swapped, resulting in the development of new characteristics in gametes and the development of a new organism that is different from its parents. Therefore, sexual reproduction helps in biological development. Through sexual reproduction, organisms have greater chances of survival because the organism is more capable due to genetic variations. The number of organisms also increases through sexual reproduction. Therefore, sexual reproduction is the best method of reproduction.
Question 11. Why is the offspring produced by asexual reproduction called a clone?
Answer:- Morphologically and genetically similar organisms are called clones. The offspring produced by asexual reproduction is genetically and morphologically identical to its parent, hence it is called a clone.
Question 12. The offspring formed as a result of sexual reproduction have good chances of survival. Why ? Is this statement true all the time?
Answer:- Genetic variations arise due to exchange of chromosomes during sexual reproduction. Which is transferred from parent to offspring. Due to the generation and fertilization of gametes, an offspring with new and better qualities is born. Therefore, the offspring resulting from sexual reproduction have good chances of survival.
This statement is not always correct. When parents suffer from disease, that disease gets transferred to the coming generations.
Question 13. How is the progeny formed through asexual reproduction different from the progeny formed through sexual reproduction?
Answer:- The child produced by asexual reproduction is genetically and structurally identical to the parent, that is, it is a clone of its parent. On the contrary, the offspring produced by sexual reproduction is genetically different from the parent.
Question 14. What do you understand by vegetative propagation? Give any two suitable examples.
Answer:- Vegetative propagation is a method of reproduction in which any vegetative part of the plant body acts as a propagator and develops into a new plant. Vegetative parts of the mother plant; For example, regeneration of a new plant from root, stem, leaf, bud etc. is called vegetative propagation. Following are two examples of vegetative propagation –
1. In the Bryophyllum plant, vegetative bodies are produced from the edges of the leaves which separate from the mother plant and give birth to a new plant.
2. The nodes present in the potato tuber are helpful in vegetative propagation. Buds are located in the nodes and each bud gives birth to a new plant.
Question 15. Explain –
(a) Teenage stage
(b) progenitor stage
(c) Senescence stage or old age.
Answer :-
(a) Juvenile phase – All living organisms pass through a certain stage before becoming sexually mature, only after this they can reproduce sexually. This stage is called juvenile stage in animals and vegetative stage in plants. Its duration varies in different organisms.
(b) Reproductive phase – At the end of adolescence or vegetative phase, the reproductive phase or reproductive phase begins. This stage can be clearly identified in plants. Because flowering starts in the plants. Many physical and morphological changes also occur in animals. In this stage organisms produce offspring.
Becomes eligible. This condition varies in different organisms.
(c) Senescent phase – This is the last stage or third stage of the life cycle. The end of the reproductive age can be considered the senescence stage or the beginning of senility. In this stage, metabolic processes start slowing down, tissues start decaying and body parts gradually stop functioning and ultimately the organism dies. This is also called old age.
Question 16. Despite their complexity, large organisms have achieved sexual reproduction, why?
Answer:- Sexual reproduction, despite being complex and slow, is good in many ways. During this type of reproduction, new characteristics develop due to exchange of chromosomes which keep getting transferred from generation to generation. Variations also arise due to exchange of chromosomes, which helps in biological evolution. Due to these properties, sexual reproduction is found in larger organisms.
Question 17. Explain that meiosis and gametogenesis are always inter-related.
Answer:- Meiosis and gametogenesis processes occur during reproduction in sexually reproducing organisms. Generally sexually reproducing organisms are diploid. The process of gamete formation is called gametogenesis. The formation of sperms is called spermatogenesis and the formation of eggs is called oogenesis. These are produced in male and female gonads respectively. The number of chromosomes in gametes is reduced to half, that is, gametes are haploid. The gametogenesis process occurs by meiosis. Therefore, the processes of gametogenesis and meiosis are interrelated. As a result of fertilization, male and female haploid gametes combine to form a diploid zygote. A new organism develops from a diploid gamete through embryonic development.
Question 18. Identify the part of each flowering plant and write whether it is haploid (n) or diploid (2n).
1.Ovary
2. Anther
3. Egg or ovum
4. Pollen
5. Male gametes
6. Zygote
Answer :-
Floral part –
1. Ovary – Diploid (2n)
2. Anther – Diploid (2n)
3. Egg or ovum (Ova) – haploid (n)
4. Pollen grain – haploid (n)
5. Male gamete – haploid (n)
6. Zygote – Diploid (2n)
[Zygote is a diploid structure (2n) formed by the union of sperm and egg.
Question 19. Explain external fertilization. Explain its disadvantages.
Answer :-
External Fertilization – The conjugation or fusion of sperm (male gamete) and egg (female gamete) is called fertilization. As a result, diploid zygote is formed. In most algae, fish and amphibians, the fusion of sperm (male gamete) and egg (female gamete) takes place outside the body in water, this is called external fertilization.
Disadvantages of External Fertilization –
1. Living organisms have to produce a large number of gametes so that the chances of fertilization increase, that is, they have less chances for gamete fusion.
2. Progeny are produced in large numbers.
3. The offspring go through the situation of being hunted by predators, as a result of which their survival becomes risky i.e. the offspring are able to survive in less numbers.
Question 20. Differentiate between zoospore (asexual mobile spore) and zygote.
Answer :-
Zoospore (asexually motile spore) – It is a naked, mobile, flagellated structure which is the unit of asexual reproduction. They are formed from the protoplasm of the parent cell by mitotic division. The flagella located on their front part help in swimming in water. These mobile spores are formed in vacuoles. Example – Ulothrix, Chlamydomonas etc.
Zygote – The structure formed by fertilization of male and female gametes during sexual reproduction is called zygote. It is diploid (2n) and develops into an embryo or larva. Sexually reproducing organisms develop from the zygote. In organisms undergoing external fertilization, zygote is formed in the external medium (water); Like – frog, whereas in organisms having internal fertilization it develops in the body of the female; Like – humans etc.
Question 21. Explain the post-fertilization changes in a flower.
Answer:- Post fertilization development in a flower – Double fertilization and triple fusion take place in flowering plants. As a result, a diploid zygote and a triploid primary endospermic nucleus are formed in the embryo sac. These form embryo and endosperm respectively. Endosperm provides nutrition to the developing embryo. Along with this, the following changes take place in the ovule, as a result of which seed is formed from the ovule and pericap is formed from the ovary.
1.Chicotyle – Forms the hypocotyl.
2. Integument – Forms the seed coat.
3. Oviduct – Makes the endosperm.
4. Nucellus – usually gets destroyed, sometimes due to accumulation of food it forms perisperm.
1.embryosac
* Egg cell – forms an embryo.
*Supporting cells (synergids) – are destroyed.
*Antipodal cells – are destroyed.
*Polar nuclei – forms endosperm.
1. Ovary wall – forms pericarp. The embryo remains dormant in the seed. The seed is surrounded from all sides by an integument made of testa & tegmen. The embryo is located between the cotyledons. Depending on the structure of the fruit wall, fruits are juicy or dry.
Question 22. What is a bisexual flower? Collect five bisexual flowers from your surroundings and find out their common (local) and scientific names with the help of your teacher.
Answer :- Bisexual flower – When the flower has both androecium and gynoecium, then the flower is called bisexual. Generally bisexual flowers found in nearby areas like –
1.Mustard – Brassica campestris
2. Radish – Raphanus sativus
3. Pea – Pisum sativum
4. Beans – Dolichos tablab
5. Amaltas – Cassia fistula
6. Hibiscus – Hibiscus rosa sinensis
Question 23. Examine some flowers of any cucurbit plant and try to identify the stamen and pistil flowers. Do you know the names of other monoecious plants?
Answer :-
Cucurbit plant flowers are unisexual. The gynoecium is absent in the male flower. There are five stamens in the flower. These are usually combined in the form 2 + 2 + 1. Their anthers are twisted.
The anther (androecium) is absent in the female flower. The gynoecium is composed of tricotyledon, monocotyledon, unilocular and inferior ovary. In this, wall-attached ovule formation takes place. The simple juicy fruit developed from the ovary is called pepo.
Other unisexual plants –
1. Mecca – Zeq muys
2. Dates – Phoenix sylvestris
3. Papaya – Carica papaya
4. Coconut – Cocos nucifera
Question 24. Why is the survival of the offspring of oviparous animals more risky than that of viviparous animals? Explain.
Answer :- In oviparous animals, the development of the fertilized egg (zygote) takes place outside the body of the female animal. The female deposits eggs covered with a calcareous shell in a safe place. The child develops as a result of embryonic development in eggs. The child is released after a certain period of time as a result of the hatching of the egg. External development takes place in the oocyte. It is affected by adverse environmental conditions and predatory animals. As a result, the survival of these creatures becomes more risky. Oviparous animals get less time for development. Therefore, the internal maturity in these organisms is less as compared to viviparous ones. For example, animals of fish, amphibians, reptiles and birds are oviparous.
In viviparous, the development of the fertilized egg (zygote) takes place in the body of the female animal. This is called internal development. They are born through delivery after the child’s development is complete, due to the child’s development being internal and development taking longer time, their survival is relatively less risky. Due to internal development, they remain safe from the external environment and external predators. This is the reason why the survival of live breeders is higher than that of egg breeders.