Reproduction, likewise, is a characteristic of living organisms. In multicellular organisms, reproduction refers to the production of progeny possessing features more or less similar to those of parents. Invariably and implicitly we refer to sexual reproduction. Organisms reproduce by asexual means also. Fungi multiply and spread easily due to the millions of asexual spores they produce. In lower organisms like yeast and hydra, we observe budding. In Planaria (flat worms), we observe true regeneration. i.e., a fragmented organism regenerates the lost part of its body and becomes, a new organism. The fungi, the filamentous algae, the protonema of mosses, all easily multiply by fragmentation. When it comes to unicellular organisms like bacteria, unicellular algae or Amoeba. reproduction is synonymous with growth, i.e., increase in number of cells. We have already defined growth as equivalent to increase in cell number or mass. Hence, we notice that in single-celled organisms, we are not very clear about the usage of these two terms - growth and reproduction. Further, there are many organisms which do not reproduce (mules, sterile worker bees. Infertile human couples, etc). Hence, reproduction also cannot be an all-inclusive defining characteristic of living organisms. Of course, no non-living object is capable of reproducing or replicating by itself.

Which set of organisms reproduce by asexual mode of reproduction) fragmentation)?

(a) Amoeba, fungi and earthworm

(b) Earthworm, bacteria and fungi

(c) Hydra, fungi, Amoeba and bacteria

(d) Fungi, filamentous algae and protonema of mosses

(d)

 

p. Yeast                                       

1. regeneration 

q. Hydra                                     

2. budding

r. Protonema of mosses             

3.Fragmentaion

s. Filamentous Algae

 

t. Planaria

 

u. Flat worms

 
Match the following:


 

a. (p-2); (q-1); (r-2); (s-2); (t-1); (u-3)

b. (p-3); (q-3); (r-2); (s-1); (t-1); (u-3)

c. (p-3); (q-1); (r-3); (s-2); (t-2); (u-1)

d. (p-2); (q-2); (r-3); (s-3); (t-1); (u-1)

d

 

Reproduction cannot be:

a. Asexual

b. Characteristics of living organisms

c. Synonymous of growth in multicellular organism

d. A form of fragmentation

c

 

Increase in number can be-

a. Growth

b. Reproduction

c. Both a and b

d. Accumulation

c

 

Reproduction cannot be an all-inclusive defining characteristic of living organism because of

a. Asexual reproduction

b. Non living organisms also replicate

c. Examples of worker bees

d. May occur in all type of living systems instead of living organisms

c

 

How many of the following may not or cannot reproduce?
Humans, Worker bees, Mules, Boulders, Fungi, Protonema of mosses.

a. 4

b. 3

c. 1

d. 5

a

 

In --------- organisms, --------is synonymous with -------.

a. Unicellular, increase in mass and increase in number

b. Multicellular, increase in mass and increase in number

c. Unicellular, Reproduction and growth

d. Multicellular, Reproduction and growth

c

 

 

25. Evolutionary history of an organism is known as : [NEET’06]

(1) Phylogeny

(2) Ancestry

(3) Palaeontology

(4) Ontogeny

a

 

Consider the following two statements:

I. In the single-celled organisms, we are not very clear about the usage of the two terms – growth and reproduction.

II. When it comes to unicellular organisms like bacteria, unicellular algae or amoeba, reproduction is synonymous with growth, i.e., increase in number of cells.

(a) Both I and II are true and II explains I

(b) Both I and II are true but II does not explain I

(c) I is true but II is false

(d) Both I and II are false

a

 

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