Sexual rep in flowering plant

Question 1

Are we not lucky that plants reproduce sexually? The —- that we enjoy gazing at, the —- that we swoon over, the — that attract us, are all there as an aid to sexual reproduction.

Answer 1

myriads of flowers
scents and the perfumes
rich colours

Question 2

Flowers do not exist only for us to be used for —.

Answer 2

our own selfishness

Question 3

All flowering plants (—-) show sexual reproduction. T/F

Answer 3

Angiosperms
True

Question 4

A look at the diversity of structures of the — , —- and — shows an amazing range of —- to ensure formation of the end products of
sexual reproduction, the — and —-.

Answer 4

inflorescences, flowers , floral parts,
adaptations
fruits and seeds

Question 5

Human beings have had an intimate relationship with —- since time immemorial.

Answer 5

flowers

Question 6

Flowers are objects of —- (5) value
– they have always been used as —-for conveying important human feelings such as love, affection,
happiness, grief, mourning, etc.

Answer 6

aesthetic, ornamental, social, religious and cultural
symbols

Question 7

To a biologist, flowers are — and —marvels and the —-.

Answer 7

morphological and embryological
sites of sexual reproduction

Question 8

Much before the actual flower is seen on a plant, the — has taken place.

Answer 8

decision that the plant is going to flower

Question 9

Several — and —- changes are initiated which lead to the differentiation and further development of the —-.

Answer 9

hormonal and structural
floral primordium

Question 10

Inflorescences are formed which bear the —- and then the —-.

Answer 10

floral buds
flowers

Question 11

In the flower the male and female reproductive structures, the — and — differentiate and develop.

Answer 11

androecium and the gynoecium

Question 12

Androecium consists of a whorl of —- representing the male reproductive organ and the — represents the female reproductive organ.

Answer 12

stamens
gynoecium

Question 13

Two parts of a typical stamen – the —- called the filament, and the —
called the anther.

Answer 13

long and slender stalk
terminal generally bilobed structure

Question 14

The proximal end of the filament
is attached to the —- of the flower.

Answer 14

thalamus or the petal

Question 15

The — and —- of stamens are variable in flowers of different species.

Answer 15

number and length

Question 16

A typical angiosperm anther is — with each lobe having —-, i.e. they are —–

Answer 16

bilobed
two theca, i.e., they are dithecous

Question 17

Often a —– runs —- separating the theca.

Answer 17

longitudinal groove
lengthwise

Question 18

The —- of an anther is very distinct in the transverse section of the anther.

Answer 18

bilobed nature

Question 19

The anther is a —-sided (—) structure consisting of — located at the corners, two in each lobe.

Answer 19

four
tetragonal
four microsporangia

Question 20

The microsporangia develop further and become —-

Answer 20

pollen sacs.

Question 21

Pollen sac extend — all through the —- and are packed with —-

Answer 21

longitudinally
length of an anther
pollen grains.

Question 22

Structure of microsporangium:
In a transverse section, a typical microsporangium appears — in outline.

Answer 22

near circular

Question 23

Microsporangium generally surrounded by — wall layers – the —, —, — and —–.

Answer 23

four
epidermis, endothecium, middle layers and the tapetum

Question 24

The — three wall layers perform the function of —- and help in
—- .

Answer 24

outer
protection
dehiscence of anther to release the pollen

Question 25

The innermost wall layer is the ---. It nourishes the ----.

Answer 25

tapetum developing pollen grains

Question 26

Cells of the tapetum possess ----cytoplasm and generally have---- nucleus. Can you think of how tapetal cells could become BI-NUCLEATE?

Answer 26

dense more than one

Question 27

When the anther is ---, a group of ---, ----- cells called the ---- tissue occupies the centre of each microsporangium.

Answer 27

young compactly arranged homogenous cells sporogenous

Question 28

Microsporogenesis : As the anther develops, the cells of the ----- undergo meiotic divisions to form ----. What would be the ploidy of the cells of the tetrad?

Answer 28

sporogenous tissue MICROSPORE TETRADS

Question 29

As each cell of the sporogenous tissue is capable of giving rise to a ----. Each one is a ----.

Answer 29

microspore tetrad potential pollen or microspore mother cell

Question 30

The process of formation of ---- from a ---- through meiosis is called microsporogenesis.

Answer 30

microspores pollen mother cell (PMC)

Question 31

The microspores, as they are formed, are arranged in a ----–the ----

Answer 31

cluster of four cells microspore tetrad

Question 32

As the anthers --- and ----, the microspores dissociate from each other and develop into ---

Answer 32

mature and dehydrate pollen grains

Question 33

Inside each microsporangium ---- of microspores or pollen grains are formed that are released with the ----

Answer 33

several thousands dehiscence of anther

Question 34

The ----- represent the male gametophytes.

Answer 34

pollen grains

Question 35

If you touch the ---- of Hibiscus or any other flower you would find deposition of ----- on your fingers.

Answer 35

opened anthers yellowish powdery pollen grains

Question 36

Sprinkle pollen grains on a drop of --- taken on a ---- and observe under a microscope. You will really be amazed at the variety of ----– sizes, shapes, colours, designs – seen on the pollen grains from different species

Answer 36

water, glass slide architecture

Question 37

Pollen grains are generally ---measuring about ---- in ----.

Answer 37

spherical 25-50 micrometers diameters

Question 38

Pollen has a prominent ---- wall.

Answer 38

two-layered

Question 39

The ---- outer layer called the ---- is made up of ----

Answer 39

hard, exine sporopollenin

Question 40

Sporopollenin is one of the ---- known.

Answer 40

most resistant organic material

Question 41

Sporopollenin can withstand ---- and ----. ---- that degrades sporopollenin is so far known.

Answer 41

high temperatures strong acids and alkali No enzyme

Question 42

Pollen grain exine has --- called ---- where sporopollenin is absent.

Answer 42

prominent apertures germ pores

Question 43

Pollen grains are well preserved as --- because of the presence of ---.

Answer 43

fossils sporopollenin

Question 44

The exine exhibits a ----- Why do you think the exine should be hard? What is the function of germ pore?

Answer 44

fascinating array of patterns and designs.

Question 45

The inner wall of the pollen grain is called the --- .

Answer 45

intine

Question 46

Intine is a--- and ---- layer made up of ----.

Answer 46

thin and continuous cellulose and pectin

Question 47

The cytoplasm of pollen grain is surrounded by a ----.

Answer 47

plasma membrane

Question 48

When the pollen grain is mature it contains --- cells, the ----

Answer 48

two vegetative cell and generative cell

Question 49

The vegetative cell is ---, has ---- and a ---- nucleus.

Answer 49

bigger abundant food reserve large irregularly shaped

Question 50

The generative cell is --- and floats in the -----.

Answer 50

small cytoplasm of the vegetative cell

Question 51

Generative cell is --- shaped with --- and a nucleus.

Answer 51

spindle dense cytoplasm

Question 52

In ---- of angiosperms, pollen grains are shed at this 2-celled stage. In the remaining species, the --- cell divides ---- to give rise to the ---- before pollen grains are shed (3-celled stage).

Answer 52

over 60 per cent generative, mitotically two male gametes

Question 53

Pollen grains of many species cause ---- and ---- in some people often leading to --- respiratory disorders–---, -----, etc.

Answer 53

severe allergies, bronchial afflictions chronic asthma, bronchitis

Question 54

It may be mentioned that ---- that came into India as a --- with----, has become --- in occurrence and causes pollen allergy

Answer 54

Parthenium or carrot grass contaminant imported wheat ubiquitous

Question 54

Pollen grains are rich in ---. It has become a fashion in recent years to use pollen tablets as food supplements. In western countries, a large number of pollen products in the form of tablets and syrups are available in the market. Pollen consumption has been claimed to increase the performance of athletes and race horses (Figure 2.6).

Answer 54

nutrients

Question 55

It has become a ---- in recent years to use ---- as --- supplements.

Answer 55

fashion pollen tablets food

Question 55

In --- countries, a large number of pollen products in the form of ---- and ---- are available in the market.

Answer 55

western (england in pic) tablets and syrups

Question 56

Pollen consumption has been claimed to increase the performance of --- and ----

Answer 56

athletes and race horses

Question 57

When once they are shed, pollen grains have to land on the stigma before ---- if they have to bring about fertilisation.

Answer 57

they lose viability

Question 58

How long do you think the pollen grains retain viability? The period for which pollen grains remain viable is ---- and to some extent depends on the ----, ----

Answer 58

highly variable prevailing temperature and humidity

Question 59

In some ---- such as rice and wheat, pollen grains lose viability within ----

Answer 59

cereals, 30 minutes of their release,

Question 60

In some members of ---, ---, ---- they maintain viability for months.

Answer 60

Rosaceae, Leguminoseae and Solanaceae,

Question 61

You may have heard of storing ---- of many animals including humans for ---- .

Answer 61

semen/ sperms artificial insemination

Question 62

It is possible to store pollen grains of a ---- for ---- in ---- . Such stored pollen can be used as pollen banks, similar to seed banks, in ----

Answer 62

large number of species years liquid nitrogen (-196C) crop breeding programmes

Question 63

The --- represents the female reproductive part of the flower.

Answer 63

gynoecium

Question 64

The gynoecium may consist of a single pistil (----) or may have more than one pistil (----).

Answer 64

monocarpellary multicarpellary

Question 65

When there are more than one, the pistils may be fused together (--) or may be free (---)

Answer 65

syncarpous apocarpous

Question 66

Each pistil has three parts the ---, ---, ---- .

Answer 66

stigma, style and ovary

Question 67

The stigma serves as a--- for pollen grains.

Answer 67

landing platform

Question 68

The style is the ---- part beneath the stigma.

Answer 68

elongated slender

Question 69

The ---- part of the pistil is the ovary.

Answer 69

basal bulged

Question 70

Inside the ovary is the ovarian cavity (---). The ---- is located inside the ovarian cavity. .

Answer 70

locule placenta

Question 71

Arising from the placenta are the ---, commonly called ---.

Answer 71

megasporangia ovules

Question 72

The number of ovules in an ovary may be one (----) to many (---).

Answer 72

wheat, paddy, mango papaya, water melon, orchids

Question 73

The Megasporangium (----) : structure of a typical angiosperm ovule

Answer 73

Ovule

Question 74

The ovule is a --- attached to the placenta by means of a --- called ---.

Answer 74

small structure stalk == funicle

Question 75

The body of the ovule fuses with funicle in the region called ---.

Answer 75

hilum

Question 76

Thus, hilum represents the junction between ---, ---- .

Answer 76

ovule and funicle

Question 77

Each ovule has one or two protective envelopes called ---.

Answer 77

integuments

Question 78

Integuments encircle the ---- except at the tip where a small opening called the --- is organised.

Answer 78

nucellus micropyle

Question 79

Opposite the micropylar end, is the ----, representing the --- of the ovule.

Answer 79

chalaza basal part

Question 80

Enclosed within the integuments is a mass of cells called the ---.

Answer 80

nucellus

Question 81

Cells of the nucellus have ----.

Answer 81

abundant reserve food materials

Question 82

Located in the nucellus is the --- or ---.

Answer 82

embryo sac female gametophyte

Question 83

An ovule generally has a --- embryo sac formed from a megaspore

Answer 83

single

Question 84

Megasporogenesis : The process of formation of --- from the ----.

Answer 84

megaspores megaspore mother cell

Question 85

Ovules generally differentiate --- megaspore mother cell (MMC) in the --- region of the nucellus.

Answer 85

a single micropylar

Question 86

MMC is a --- cell containing --- and a --- nucleus.

Answer 86

large dense cytoplasm, prominent

Question 87

The MMC undergoes --- What is the importance of the MMC undergoing meiosis? Meiosis results in the production of -----megaspores

Answer 87

meiotic division. four

Question 88

Female gametophyte : In a majority of flowering plants, one of the megaspores is ---- while the other three ----.

Answer 88

functional degenerate

Question 89

Only the functional megaspore develops into the ----

Answer 89

female gametophyte (embryo sac).

Question 90

This method of embryo sac formation from a single megaspore is termed ---- What will be the ploidy of the cells of the nucellus, MMC, the functional megaspore and female gametophyte?

Answer 90

monosporic development.

Question 91

The --- of the functional megaspore divides --- to form two ---- which move to the ----, forming the 2-nucleate embryo sac.

Answer 91

nucleus mitotically, nuclei opposite poles

Question 92

Two more sequential mitotic nuclear divisions result in the formation of the --- and ---- stages of the embryo sac.

Answer 92

4-nucleate and later the 8-nucleate

Question 93

It is of interest to note that these mitotic divisions are ---, that is, nuclear divisions are not followed IMMEDIATELY by ---

Answer 93

strictly free nuclear cell wall formation.

Question 94

After the 8-nucleate stage, --- are laid down leading to the --- of the typical female gametophyte or embryo sac.

Answer 94

cell walls organisation

Question 95

--- of the 8 nuclei are surrounded by Cell walls and organised into --- while the remaining --- called ---- are situated ---- in the LARGE central cell

Answer 95

6 Cells 2 nuclei- polar nuclei BELOW the egg apparatus

Question 95

There is ---- of the cells in an embryo sac

Answer 95

Characteristic distribution

Question 95

--- cells are grouped together at micropylar end and constitute ----

Answer 95

3, egg apparatus

Question 96

Egg apparatus consists of 2 --- and 1 ---

Answer 96

Synergids Egg cell

Question 97

The synergids have ---- at the ---- tip called ----

Answer 97

Special cellular thickenings, micropylar tip --> filliform apparatus

Question 98

----- play an imp role in guiding the pollen tubes into the ----

Answer 98

Filliform apparatus Synergids

Question 99

Three cells at chalazal end are called ---

Answer 99

Antipodal

Question 100

Large central cell has --- nuclei

Answer 100

2 Polar nuclei

Question 101

Thus a typical angiosperm embryo sac at maturity has ---

Answer 101

7 cells tho it is 8 nucleate