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Published on: 30/07/2019
Reproduction in Organisms
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1.
Name two groups of plants that have a haploid body.
2.
Mention the unique feature with respect to flowerin and fruiting in bamboo species.
3.
How are Cucurbita plants different from papaya plants with reference to the flowers they bear?
4.
Cucurbits and papaya plants bear staminate and pistillate flowers. Mention the categories they are put under separately on the basic of the type of flowers they bear.
5.
Name the common phenomenon with reference to reproduction in rotifers, honey bees and turkey.
6.
In which of the following organism, self-fertilization is seen?
Fish
Roundworm
Earthworm
Liver fluke
7.
scion grafted to a stock. The quality of fruits produced will be determined by the genotype of
Stock
Scion
Both stock and scion
Neither stock or scion
8.
Which of the following statements is true of ginger?
Germinating bud appears from the eye of the stem tuber.
Germinating bud appears from the node of the rhizome
Germinating bud appears from the notch of the leaf margin.
9.
Which of the following statements is true of Bryophyllum?
Germinating bud appears from the eye of the stem tuber.
Germinating bud appears from the node of the rhizome.
Geminating bud appears from the notch at the leaf margin.
10.
Which of the following statements is true of yeast?
The cell divides by binary fission. One of them develops into a bud.
The cell divides unequally. The smaller cell develops into a bud.
The cell produces conidia, which develop into a bud.
11.
What are hermaphrodites? Name two hermaphrodite animals
12.
Is Marchantia monoecious or dioecious? Why? where are the sex organs borne in this plant?
13.
What are pre-fertilisation events? Name the two main pre-fertilisation events.
14.
Give reasons as to why cell division cannot be a type of reproduction in multicellular organisms.
15.
Is there a relation between the size of an organism and its life span? Give two examples in support of your answer.
16.
A list of three flowering plants is given below. Which ones out of them are
(i) monoecious and
(ii) bearing pistillate flowers? Date palm, Cucurbits and Pea.
17.
The cell division involved in gamete formation is not of the same type in different organisms. Justify.
18.
Explain the role of tapetum in the pollen grain wall formation.
19.
Differentiate between oviparous and viviparous animals with an example of each.
20.
A farmer cultivates sugar cane and rose by usin stem cuttings. He found that some of the cuttings did not continue to grow into new plants. As a student of Agriculture; Shanu gives some points to be followed.
(a) Can you suggest a reason for this?
(b) Enlist the aspects that Shanu must have given for consideration, while preparing stem cuttings for propagation.
(c) Name two other plants which are also propagated by stem cuttings.
(d) What value (s) is/are shown by Shanu?
21.
What are vegetative propagules? Name any four of them along with an example for each.
1.
( )
Algae and Bryophytes.
2.
( )
Bamboo flowers only once in its life time, generally after 50-100 years. It produces large number of fruits and dies.
3.
( )
Papaya plants are dioecious as an individual plant bears exclusively either staminate flowers or pistillate flowers.
4.
( )
Cucurbits are monoecious, as staminate and pistillate flowers are found in the same individual plant.
5.
( )
Reproduction
6.
(d)
Liver fluke
7.
(b)
Scion
8.
(b)
Germinating bud appears from the node of the rhizome
9.
(c)
Geminating bud appears from the notch at the leaf margin.
10.
(b)
The cell divides unequally. The smaller cell develops into a bud.
11.
Hermaphrodites are those bisexual organisms which posses both male and female reproductive organs in the same body, e.g. Tapeworm and earthworm.
12.
1. Marchantia is dioecious, because an individual plant of Marchantia bears exclusively either male or female sex organs.
2. The male sex organs are borne on the antheridiophores and female sex organs on archegoniophores.
13.
1. Pre-fertilisation events are those events of sexual reproduction that occur prior to fusion of gametes (syngamy).
2. Gametogenesis and gamete transfer are the two major pre-fertilisation events.
14.
(i) In mullticellular organisms, cells/ tissues are specialised for various functions; the function of reproduction is performed by one group of speciallised cells.
(ii) Not all cells of a multicellular organism retains the power of division at maturity; the cells which retain the power of division are localised and they alone can help in reproduction.
15.
No, there is no relationship between the size of an organisms and its lifespan, e.g.
1. The size of crows and parrots is almost same, but the lifespan of crows is 15 years while that of parrots is 140 years.
2. A mango tree has a much shorter lifespan, compared to a peepal tree, though they both are of similar size.
16.
(i) Cucurbits are monoecious.
(ii) Date palm is dioecious and some of the plants bear exclusively pistillate flowers.
17.
1. In haploid organisms, showing haplontic life cycle, gamete formation involves only mitosis; the diploid zygote formed by the fusion of two haploid gametes, undergoes meiosis (zygotic meiosis).
2. In diploid organisms, showing diplontic or haplodiplontic life cycle, gamete formation involues meiosis (gametic meiosis) and haploid gametes are formedl; the diploid zygote undergoes mitosis to form diploid individuals.
18.
Role of tapetum in the pollen grain wall formation
During microsporogenesis, the cells of tapetum provide various enzymes, hormones, amino acids and other nutritive materials to the dividing microsporocytes. The main functions of tapetum are:
1. Transportation of nutrients into anther locule at the time of meiosis in spore mother cells.
2. Secretion of enzymes and hormones.
3. Production of Ubisch bodies which are coated with sporopollenin to cause thickening of exine.
4. Secretion of any oily material (pollen kit) over outerside of mature pollen.
5. Secretion of special proteins for pollen to recognise compatibility.
19.
| Oviparous animals | Viviparous animals |
| These are the animals which lay fertilised or unfertilised eggs. | The are the animals which give birth to young ones. |
| Chances of survival are less as off-spring of oviparous animals are at a great risk as they are threatened by their predators and unfavourable environmental conditions, e.g. frogs, birds. | Chances of survival are hih as offspring of viviparous animals are protected by the parent organism from predators/enemies and unfavourable climate, eg. Human beings/mammals. |
20.
(a) (i) The polarity of the cutting would not have been correct.
(ii) It can be due to absence of buds.
(iii) The cutting may have been selected from a very old branch.
(b) (i) The cutting must be selected from a branch that is neither very old nor very young.
(ii) There should be enough number of buds.
(iii) The polarity of the cutting should be considered.
(iv) The season of growing must be properly selected.
(c) Bougainvillea, china rose, cotton, etc.(any two)
(d) Shanu's concern for fellow citizen and use of his knowledge for the benefit of the society
21.
Those vegetative structures of plants which are capable of giving rise to new individuals/plants, are called vegetative propagules, e.g.. Runner - Oxalis.
| Leaf buds | Bryophyllum |
| Offset | Water hyacinth |
| Eyes' on tuber | Potato |
| Bulbil | Agave |
| Rhizome | Ginger (any four) |
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