Please refer to Reproduction in Organisms Class 12 Biology Important Questions with answers below. These solved questions for Chapter 1 Reproduction in Organisms in NCERT Book for Class 12 Biology have been prepared based on the latest syllabus and examination guidelines issued by CBSE, NCERT, and KVS. Students should learn these solved problems properly as these will help them to get better marks in your class tests and examinations. You will also be able to understand how to write answers properly. Revise these questions and answers regularly. We have provided Notes for Class 12 Biology for all chapters in your textbooks.

Important Questions Class 12 Biology Chapter 1 Reproduction in Organisms

All Reproduction in Organisms Class 12 Biology Important Questions provided below have been prepared by expert teachers of Standard 12 Biology. Please learn them and let us know if you have any questions.

Question. Name the stage from where every sexually reproducing organism begins their life.
Answer : Zygote

Question. How do the following organisms reproduce? Yeast, Amoeba.
Answer : Yeast- Budding , Amoeba-binary fission

Question. What is the significance of reproduction?
Answer : Continuity of species

Question. Name the type of reproduction where in the off springs produced are identical to each other and to the parent.
Answer : Asexual reproduction

Question. In seed plants how the non-motile gametes are carried to female gamete?
Answer : Through Pollen grains

QuestionName the stage of growth and maturity in the life of animals before they can reproduce sexually.
Answer : Juvenile phase

Question. What are continuous breeders and seasonal breeders?
Answer : Reproductively active throughout their reproductive phase, exhibit only during favourable seasons

Question. Name the type of fertilization where in the survival of the organism up to adulthood is threatened.
Answer : External fertilisation

Question. No organism is immortal, then why do we say there is no natural death in single – celled organisms?
Answer : Parent cell divides to give rise to new individuals

Question. Name the plant which flower only once in their lifetime.
Answer : Bamboo

Question. What is a meiocyte?
Answer : Gamete mother cell undergo meiosis

Question. What do you mean by clones?
Answer : Morphologically and genetically similar individuals

Question. What is a vegetative phase in plants?
Answer : Period of growth in plants

Question. Name the scientific name of the plant which flower once in 12 years.
Answer : Strobilanthus kunthiana

Question. Name the type of plants that show clear cut vegetative, reproductive and senescent phases.
Answer : Annual , biennial

Question. Why do you refer Water Hyacinth as an invasive weed? Why is it difficult to get rid off them?
Answer : Drains oxygen from water, death of fishes=?

Question. Differentiate between asexual and sexual method of reproduction.
Answer : Single parent ,two parents ;with or without gamete formation , fusion of gametes

Question. Where does syngamy occur? Explain with examples.
Answer : External fertilization- outside amphibians , internal fertilization- internal reptiles

Question. Gametes are always haploid. How are the gametes produced from a haploid plant body and a diploid plant body?
Answer : Mitosis by haploid ,meiosis by diploid

Question. Name the asexual reproductive structures of the following: Chlamydomonas, Penicillum, Hydra,Sponge.
Answer : Zoospores ,Conidia , Buds ,Gem mules

Question. Explain the following terms. Isogametes, An isogametes, staminate flower, Pistillate flower.
Answer : Similar in appearance ,dissimilar in appearance, male flower , female flower

Question. Why are Chara and Marchantia are referred to as monoecious and dioecious plants?
Answer : Both sex organs in the same individual; male & female sex organs in separate individuals

Question. What are hermaphrodite? Give an example.
Answer : Bisexual animals earthworm or any other

Question. Mention the three phases in the life cycle of plants and animals.
Answer : Vegetative , reproductive , senescent phases

Question. Why the number of male gametes produced is more than the number of female gamete?
Answer : Fail to reach female gamete , to compensate loss during transport

Question. What is parthenogenesis? Give an example.
Answer : Femal gamete, undergoes development, to form new organism, without fertilization ,Rotifers

Question. Name the gametes produced by staminate and pistillate flowers.
Answer : Male gamete , female gamete

Question. Why are offsprings of oviparous animals at a greater risk as compared to offsprings of viviparous animals?
Answer : Viviparous animals – development of embryo inside female organism proper care and protection, chances of survival is more than in oviparous

Question. Cell division is itself a mode of reproduction .Name two single celled organisms and explains this.
Answer : Binary fission in Amoeba cell divides into two halves , buds in yeast attached to parent gets separated and mature into yeast

Question. What are zoospores ? Why are they referred so?
Answer : Asexual reproductive structures of Fungi , algae , microscopic motile structures

Question. Child marriages are more prevalent in our society.
As a student of biology how will you support a ban stating the biological reasons for the same and give valid reasons.
Answer : Genuine and valid reason

Question. Life spans of organisms are not necessarily correlated with their sizes. Explain
Answer : Size of crow and parrot are not very different ,life span is 15 and 140 years

Question. Study the figure, label the parts
(mage) 34
Answer : A -Seed B – Pericarp

Question. What are vegetative propagules? Name the vegetative propagules of the following plants. Ginger, Agave, Bryophyllum , Water hyacinth.
Answer : Structures used for vegetative propagation , Rhizome , bulbil ,leaf buds, offset

Question. Explain the features exhibited by the organisms showing external fertilization to enhance the chances of syngamy. What is the disadvantage of external fertilization?
Answer : Synchrony between sexes ,release of large number of gametes. Vulnerable to predaters

Question. What do the following parts of a flower develop into after fertilization? Ovary, zygote, ovary wall, ovules.
Answer : Fruit , embryo, pericarp, seed

Question. Differentiate between oestrus and menstrual cycle with examples.
Answer : Female placental animals , exhibit cyclical changes; non-primate-cows , primatemonkeys

Question. Write the sexuality in the following organisms.
(a) earthworm
(b) Cockroach
(c) Chara
(d) Marchantia
(e) Sweet Potato
(f) Leech.
Answer : Bisexual – leech , earthworm, chara, sweet potato; unisexual-cockroach , Marchantia

Question. What are oviparous and viviparous animals? Give examples.
Answer : Oviparous –fertilised eggs covered by hard calcareous shell ,incubation, young ones hatch out eg. reptiles Viviparous – zygote develops into a young ones inside the body of female eg. mammals

Question. Give the term for the following figure A,B and C.

Answer : (A) Fusion of gametes (B) zygote (C) new individual

Question. Give the term for kinds of gametes in the given figures A and B . In the figure A give the specific terms for the gametes.

Answer : (A) Heterogametes (B) Homogametes.Egg and Sperm