Q.1. In sonic plants, the female gamete develops into embryo without fertilisation. This phenomenons known as (2019)
Parthenogenesis is the spontaneous development of an embryo from an unfertilised egg cell, It naturally occurs in variety of plants, where parthenogenesis usually is found in combination with apomeiosis (the omission of meiosis) and pseudogamous (with or without central cell fertilisation) endosperm formation, together known as apomixis (clonal seed production). Parthenocarpy is development of fruit without fertilisation.
Q.2. Offsets are produced by (2018)
(a) Nieiotic divisions
(b) Mitotic divisions
Offset is a vegetative part of a plant formed by mitosis. Meiotic division occurs in reproductive organs during formation of gametes. Parthenogenesis is the formation of embryo from ovum or egg without fertilisation. Parthenocarpy is the fruit formed without fertilisation.
Q.3. Which of the following flowers only once in its lifetime? (2018)
(a) Bamboo species
Certain bamboo species are monocarpic ,i.e., flower generally only once in llieir lifetime (after 50-100 years). Other plants (jackfruit, mango and papaya) are polycarpic, i.e., produce flowers and its many times during their lifetime.
Q.4. Which one of the following statements is not correct? (2016)
(a) Offspring produced by the asexual reproduction are called clone.
(b) Microscopic, motile, asexual reproductive structures are called zoospores.
(c) In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem.
(d) Water hyacinth, growing in the standing water, drains oxygen from water that leads to the death of fishes.
Potato, banana and ginser Propagate Vegetatively by their modified stems. Potato propagates by tuber which has buds over its eyes or nodes. These buds produce new plantlets. Banana and ginger propagate with the help of rhizomes which also have buds on nodes for the formation of new plantlets.
Q.5. Which one of the following generates new genetic combinations leading to variation? (2016)
(a) Vegetative reproduction
(c) Sexual reproduction
(d) Nucellar polyembryony
Sexual reproduction involves formation and fusion of male and female gametes. Gamete formation is accomplished through meiotic cell division which involves crossing over between non-sister chromatids of homologous chromosomes leading to new genetic recombination in gametes. Random fusion of these male and female gametes lead to the genetic variability in the offspring which although resemble their parents but also exhibit new traits of their own.
Q.6. Match column 1 with column II and select t correct option using the codes given below. (2016)
| Column I || Column II|
| A. Pistils fused together || (i) Gametogene|
|B. Formation of gametes||(ii) Pistillate|
| C. Hyphae of higher Ascomycetes ||(iii) Syncarpous|
|D. Unisexual female flower||(iv) Dikaryotic|
(a) A-(iv), B-(iii), C-(i), D-(ii)
(b) A-(ii), B-(i), C-(iv), D-(iii)
(c) A-(i), B-(ii). C-(iv), D-(iii)
(c) A-(iii), B-(i), C-(iv), D-(ii)
Q.7. Seed formation without fertilization in flowering plants involves the process of:- (2016)
(c) Somatic hybridization
Apomixis (asexual seed formation) is the result of a plant gaining the ability to bypass the most fundamental aspects of sexual reproduction: meiosis and fertilization.
Without the need for male fertilization, the resulting seed germinates a plant that develops as a maternal clone.