ZOOLOGY BOTANY CHEMISTRY

Answer :- (i) - (c), (ii) - (d), (iii) - (b), (iv) - (a).

Answer :- (a) Monoecious  (b) Monoecious  (c) Dioecious  (d) Dioecious.

Answer :- Pollination, gametogenesis, fertilisation and embryogenesis.

Answer :- On potato we find eyes in the depressions of scaly leaves which grow out to form the plants and help in vegetative propagation.

Answer:- A. Embryo, embryogenesis B. Viviparous C. Oviparous D. Fertilization, ovules.

Answer :- (a) Zoospore is a haploid and motile spore formed during asexual reproduction in lower plants and fungi. The zygote is a diploid and nonmotile cell formed due to fusion of male and female gametes in sexual reproduction. (b) Syngamy is actual fusion of male and female gametes whereas fertilization includes all the associated events that ultimately lead to syngamy.

Answer :- Fission is a type of asexual reproduction in which the unicellular parental organisms divide into two or more than two small, nearly equal sized daughter individuals. It is of two types : 1) Binary Fission 2) Multible Fission

Answer :- In coconut palm, both male and female flowers develop on the same individual. This condition is called monoecious. In date palm, the male and female flowers develop on separate individuals. This condition is called dioecious. 

Answer :- 1) Body is smaller, less muscular and weaker. 2) Beard, moustache and chest hair lacking. 3) Breasts very well developed. 

Answer :- 1) Body is larger, more muscular and stronger. 2) Beard, moustache and chest hair present. 3) Skin is more hairy. 

Answer :- Parthenocarpy is " the formation of fruits without fertilization" whereas parthenogenesis is "the formation of embryo from unfertilized egg." 

Answer :- The greatest advantage of asexual reproduction is that an organism biotype (the original organism) can be retained and multiplied indefinitely without any change or variation. The variation are normally expected if organism undergoes meiosis and Syngamy. 

Answer :- Modified tuberous roots, which possess buds, serve as Natural method of vegetative propagation. These roots develop leafy shoots (called slips) aboveground and adventitious roots underground. 

Answer :- Spores are asexually reproducing bodies produced inside the sporangia. They germinate to produce new individuals. The different kinds of spores are - zoospores, sporangiospores and chlamydospores.

Answer :- In case of binary fission, the unicellular organism divides by cell division to give rise two equal at similar offspring. In case of budding, however, the organisms produce a small bud that gradually grows in size and then separates from the parent. 

Answer :- The type of reproduction, which involves meiosis and fusion of gametes, is called sexual reproduction. It involves participation of two parents - one male and other female. 

Answer :- The type of reproduction, which does not involve meiosis and fusion of gametes, is called asexual reproduction. It involves the participation of single individual parent.

Answer :- By crowns and by suckers.

Answer :- This phenomenon is basically known as parthenogenesis. Example of one bird is turkey. 

Answer :- Chlamydomonas ; Zoospores are endogenously produced unicellular, naked and motile spores with one or two flagella. These are produced in a sac like structure called zoosporangium.

Answer :- Asexual reproduction in amoeba and paramecium.

Answer :- Juvenile phase. 

Answer :- Zoospores in algae are motile cells helping in asexual reproduction. 

Answer :- In amphibians, Syngamy occurs in water outside the body of the organism ( external fertilization and external development). In reptiles, it occurs inside the body of female (internal fertilization and external development). 

Answer :- Name of the face of lifespan is senescence and old age. The two important changes that occur during old age are - (i) End of reproductive phase and (ii) slowing of a metabolism. 

Answer :- Intraction between hormones and certain environmental factors.

Answer:- The offsprings produced by asexual reproduction are genetically similar to their parents and do not show variation. But the progeny produced by sexual reproduction show genetic variation and differences form either of the two parents as well as among themselves. 

Answer :- In plants, the units of vegetative propagation such as tuber, bulb, rhizome, etc., are called vegetative propagules. 

Answer :- Amoeba and Paramecium.

Answer :- Morphologically and genetically similar individuals produced as a result of asexual reproduction are clone. 

Answer :- Secondry sexual characters are external and Internal changes in organisms which develop at the onset of reproductive phase. 

Answer :- (a) gametes ; (b) embryo, zygote ; (c) Oviparous (d) Ovules. 

Answer :- The artificial means of vegetative reproduction are cuttings, layering, grafting and micropropagation. 

Answer :- Natural vegetative reproduction take place by modified tuberous roots having adventitious buds, underground modified stems, creeping stems, leaves, bulbils and turions.

Answer :- Hydra. 

Answer :- Yeast. 

Answer :- Bacteria and Amoeba. 

Answer :- The duration between birth and death is called life span. 

Answer :- A biological process in which an organism give rise to young ones (offspring) similar to itself is called reproduction. 

Answer :- Oviparous animals lay eggs in a safe place in the environment. In an open area, the eggs are not always safe and thr Offspings are always at a risk. The viviparous animals give birth of young ones. The fertilized eggs of oviparous animals (example:- birds, reptiles etc.) undergo a period of incubation and then their young one hatch out. This period has risk of predators. In case of viviparous animals (example :- mammals, including human being), the zygote develops into a young one inside the body of the female individual where it gets proper nourishment, care and protection. Therefore, the chances of survival of young ones are more in the viviparous animals as compared to those of oviparous animals. 

Answer :- The staminate flowers bear bright coloured petals and stamens. They do not develop fruits. The pistillate flowers develop fruits. The other unisexual plant is papaya . Date palm is also unisexual and bear unisexual flowers. 

Answer:- A bisexual flower possesses both stamens as well as carpels. 

Answer :- After fertilization, the sepals and petals and stamens wither and fall off. In some cases, the sepals remain persistent. The ovules are transformed into seeds, zygote becomes embryo and ovary becomes a fruit. 

Answer :- Gametogenesis occur inside the gametangia where meiosis occurs resulting in the formation of gametes. Embryogenesis is the development of zygote into an embryo. During this process, the zygote divides by the mitotic divisions. 

Answer :- A zoospore is usually flagellated, haploid or diploid spore formed inside a zoosporangium. The zygote, on the other hand, is always diploid and formed as a result of fusion of gametes. The zygote is usually non flagellated. 

Answer :-  Since, vegetative reproduction does not involve meiosis and fusion of gametes, it is considered as a type of asexual reproduction. 

Answer :- External fertilization occurs outside the body of the organisms. During this process, the parents release sperms and eggs into surrounding water (example, frog) where fertilization occurs. The major disadvantages of this type of fertilization are: (i) the fertilization of egg is not always sure (ii) the offspring are not protected from the Predators (iii) a large number of gametes are wasted. 

Answer:- 1) Ovary - Diploid (2n) 2) Anther - Diploid (2n) 3) Egg - Haploid (n) 4) Pollen - Haploid (n) 5) Male gamete - Haploid (n) 6) Zygote - Diploid (2n)

Answer :- The vegetative propagation involved in production of new individuals from some vegetative plant propagules such as Buds, Tubers, rhizoms etc. Examples :- 1) Potato Tubers possess buds which grow into new plants 2) Advantages buds of bryophyllum leaves grow to form new plants.

Answer :- (i) Juvenile phase is the period of growth between the birth of an individual up to reproductive maturity. (ii) Reproductive phase starts after the Juvenile phase phase the Juvenile phase phase after the Juvenile phase phase the Juvenile phase phase Juvenile phase and remains up to the stage when an organism is capable of reproduction. (iii) Senescent phase is phase of ageing when an organism loses its capacity of reproduction. In plants, it is characterized by yellowing and leaf fall.

Answer :- Asexual Reproduction results results in the production of offspring which are morphologically and genetically similar. Such individuals are called clones.

Answer :- Gametogenesis is the process of formation of haploid gametes inside the gametangia. Thus, gametes are formed as a result of meiosis so that their chromosome number becomes haploid.

Answer:- In spite of its complexity, higher organisms has restored to sexual reproduction because it enables these organisms to survive during unfavourable conditions. It contribute to evolution of species by introducing variation in population much more rapidly than asexual reproduction.

Answer :- Since asexual reproduction does not involve meiosis and fusion of gametes, the progeny formed from asexual reproduction are genetically similar to parents and they do not show variation. The individual produced as a result of meiosis and gametic fusion and exhibit genetic variation and difference from either of two parents as well as among themselves.

Answer :- Offspring formed due to sexual reproduction have better chances of Survival because the they possess the genetic material of two parents and that too shows variation. This is important for survival of species. The variation is usually advantageous and helps the offspring to survive under changing environmental conditions. Sometimes the variations are not fit for the survival of the species. Therefore we can say that this statement is always true.

Answer :- Sexual reproduction is better mode of reproduction because it needs meiosis and fusion of male and female gametes. Such a fusion involving two parents resulting in the offspring that are not identical to the parents. It also causes variation which is essential for evolution and survival of species under diverse changes in environmental factors.

Answer :- Reproduction is essential for organisms because it enables the continuity of species generation after generation.