Sexual reproduction in flowering plants Flashcards
(87 cards)
1
Q
When sepal and petal look same they are called?
A
Tepal
2
Q
Non essential flower organs
A
Petals and sepals
3
Q
Essential flower organs
A
Androecium and gynoecium
4
Q
Stamen consists of?
A
Anther and Filament
5
Q
Microsporangia mature and forms______
A
Pollen sacs
6
Q
4 layers of anther
A
Epidermis, endothecium, middle layer, tapetum
7
Q
What is microsporogenesis?
A
The formation of haploid microscopes from diploid microspore mother cell inside pollen sac by meiotic division .
8
Q
microspore develops into______
A
Pollen grains
9
Q
male gametophyte?
A
Pollen grains
10
Q
nutritional layer of anther wall?
A
Tapetum
11
Q
Ploidy level of the cells in microspore tetrad is_____
A
Haploid
12
Q
Cell wall of pollen grain?
A
Sporoderm - exine and intine
13
Q
exine is made up of
A
Sporollenin ( one of the most resistant organic material known) .
14
Q
What helps in fossilization of pollen grain?
A
Sporollenin
15
Q
What is intine made up of?
A
Cellulose and Pectin
16
Q
what is germ pore?
A
Area where sporollenin is absent
17
Q
examples of plant causing pollen allergy
A
Parthenium (carrot grass), Amanranthus, Chenopodium
18
Q
Pollen grain diameter
A
25- 50 um
19
Q
What can break sporollenin?
A
stigmatic fluid of the same species
20
Q
What is pollen viability?
A
The period for which the pollen grains retain the ability to germinate on landing on the stigma
21
Q
storage of pollen grains for years
A
in N2 at -196 C
22
Q
Pollen viability of wheat and rice
A
30 minutes
23
Q
Pollen grain are divided into
A
Two parts
VEGETATIVE CELL - bigger in size , store food
GENERATIVE CELL- small and floats in the cytoplasm of vegetative cell.
24
Q
The study of external morphology of nature of pollen grains
A
Palynology
25
Free unit of gynoecium
Pistil
26
Components of Pistil
stigma, style, ovary
27
A multicarpellary pistil may be
1. Apocarpous- Carpels are free from each other, ovaries can be fused.
2. Synocarpous- Carpels are fused, ovaries can be free
28
Ovarian Cavity
Locules
29
Parenchymatous tissue in ovary
Placenta
30
Parenchymatous means
whenever the tissue is parenchymatous it means it store food
31
Seedless fruit is obtained from
Parthenocarpy
32
Stalk of ovule is called?
Funicle
33
Two ends of Ovule
CHALAZAL END- basal end
| MICROPYLAR END- upper end
34
What is hilum?
junction between ovule and funicle or the point of attachment of funicle to the ovule
35
What is integument?
one or more protective envelops which surround the body of ovule
36
What is Nucellus?
the parenchymatous mass of tissue which forms the body of the ovule
37
In most flowering plants, pollination takes place at ____ celled stage
3
38
Mature male gametophyte is_______celled and ______ nucleate
one celled and two nucleate
39
Female gametophyte
Embryo sac
40
What is megasporogenesis?
The process of formation of megaspores from megaspore mother cell (MMC)
41
Importance of meiosis in megaspore mother cell
to ensure the formation of a haploid female gamete before fertillization
42
What is monosporic embryo (polygonum) sac?
the formation of embryo sac from single megaspore
43
Development of monosporic embryo sac (polygonum)
the functional haploid megaspore enlarges in size and by means of three successive meiotic divisions gives rise to an 8 nucleate embryo sac
44
embryo sac consists of ____ cells and _____ nuclei
7 cells and 8 nuclei
45
Egg apparatus?
group of 3 cells situated at micropylar end
46
Two types of cell in egg apparatus
centrally located egg cell which has a large vacuole
| at the sides two synergids
47
What are the finger like structures present in synergids?
filiform apparatus. It attracts and guide the pollen tube
48
What is polar nuclei?
situated in the center of embryo sac. large BINUCLEATE cell
49
What are Antipodals?
The three cell situtated at the chalazal end. They degenerate soon after fertilization
50
In monosporic embryo sac of a flowering plants, ____ no. of nuclei get surrounded by cell walls and are organized into cells
6 no. of nuclei get surrounded by cell wall
51
The arrangement of the nuclei in a normal embryo sac in dicot plant is
3+2+3
52
Polygonum type of embryo sac is found in __% of flowering plants
80%
53
_____ are the vegetative cells of embryo sac
Antipodal
54
Characteristic feature of endothecium in anther wall layers?`
cells of this layer have alpha cellulosic fibrous bands arising from inner tangential wall . It helps in dehiscence of anther.
55
Pollen posses a sticky, oily covering called_____
Pollen kit
56
A mature male gametophyte is
three celled
57
Shedding of pollen takes place at two celled in ____% of angiosperms
60%
58
Which plants came in India as a contaminant with imported wheat and is a major reason of pollen allergy in india
Parthenium
59
Most common type of ovule which is found in 82% of angiosperms
Anatropous ( ovule turns at 180 degree)
60
When ovule as well as embryo sac is curved like a horse shoe , the type is called
amphitropous
61
when micropyle, chalaza and funicle are in straight line
orthotropus
62
When ovule is turned 90 degree
hemitropous
63
Out of linear tetrad of four haploid megaspores, how many are functional and how many degenerate?
```
1 is functional ( chalazal end)
3 degenerate ( micropylar end)
```
64
The two nuclei of central cell fuse and forms____
secondary nucleus
65
Integumented megasporangium is also called ____
ovule
66
The embryo sac lies at the ________ end
micropylar
67
Examples of cleistogamy ( flower does not open)
Viola, oxalis, commelina
68
Advantages of cleistogamy
(a) ensures seed formation even in the absence of any pollinating agent
(b) cheaper for the plant as there is no need for producing nectar or fragrance
69
Disadvantages of cleistogamy
no genetic diversity
70
What is homogamy?
Maturation of both androecium and gynoecium
71
What is geitanogamy?
transfer of pollen grain from anther to stigma of another flower but of same plant. It is genetically similar as homogamy.
72
What is xenogamy?
transfer of pollen grains from anther to stigma of another flower of different plant but of same species
73
what is anemophily? example?
pollination by wind. examples- grass, wheat, sugarcane, bamboo, maize
74
Two types of hydrophily
1) EPIHYDROPHILY- on the surface of water eg. vallisneria.
| 2) HYPOHYDROPHILY- below the surface of the water. eg. Zoostera
75
true or false
| In water lily, pollination is carried out by water
false
76
What is entomophily?
Pollination by insects
77
Flower rewards
nectar, safe place for laying eggs
78
Special feature of flowers pollinated by moths
Moth fly at night so the flower need to be heavily scented not heavily coloured. The flowers pollinated by moths are generally white.
79
Examples of flowers which provide insects a safe place for laying eggs
Anormophallus, Pronuba moth lay eggs in yucca plants
80
What are outbreeding devices?
Devices or features of plant which discourage self fertilization and promote cross pollination
81
Generative pollen tube was destroyed by a laser but a normal pollen tube was still formed because
vegetative cell was not damaged
82
Angiospermic plant have chromosome no. of 12. What will be the chromosome no. in integuments and nucellus?
12
83
Exine of the pollen is formed by the activity of
tapetum
84
Male gametes or sperm are developed from generative cell by
mitotic division
85
In dicots the most common pollen tetrad is
tetrahedral
86
When the pollen tube enters the ovule through the micropyle, the phenomenon is known as
Porogamy
87
Which type of association s found between entamophilous flower and pollinating agent
mutalism
