[plants]: ALGAE

Question 1

General description of algae

Answer 1

chlorophyll-bearing
simple
thalloid
autotrophic
largely aquatic(both freshwater and marine)
organisms

Question 2

habitats

Answer 2

mainly aquatic
moist stones, soils, wood
in association with fungi(lichens) or animals(eg sloth bear)

Question 3

example of colonial form

Answer 3

volvox

Question 4

examples of filamentous forms

Answer 4

ulothrix, spirogyra

Question 5

example of plant body-like formations

Answer 5

few marine forms like kelps

Question 6

aspects of reproduction

Answer 6

vegetative, asexual,sexual

Question 7

vegetative reproduction is by

Answer 7

fragmentation

Question 8

each fragment develops a

Answer 8

thallus

Question 9

thallus

Answer 9

a plant body that is not differentiated into stem and leaves and lacks true roots and a vascular system. Thalli are typical of algae, fungi, lichens, and some liverworts.

Question 10

asexual reproduction is by

Answer 10

formation of different types of spores, the most common being the zoospores

Question 11

their zoospores are

Answer 11

flagellated(motile) and on germination give rise to new plants

Question 12

sexual reproduction takes place through

Answer 12

fusion of two gametes

Question 13

example of same sized flagellated(motile) gametes

Answer 13

ulothrix

Question 14

example of same sized non-flagellated(non-motile) gametes

Answer 14

spirogyra

Question 15

isogamy

Answer 15

Isogamy is a form of sexual reproduction that involves gametes of similar morphology.
Because both gametes look alike, they generally cannot be classified as male or female.

Question 16

anisogamy

Answer 16

Anisogamy is the form of sexual reproduction that involves the union or fusion of two gametes, which differ in size and/or form. The smaller gamete is male, a sperm cell), whereas the larger gamete is female, typically an egg cell. Anisogamy is common and widespread in multicellular organisms.

Question 17

example of anisogamous species

Answer 17

eudorina

Question 18

example of isogamous species

Answer 18

ulothrix, spirogyra

Question 19

example of oogamous species

Answer 19

volvox, fucus

Question 20

oogamy

Answer 20

It is a form of anisogamy (heterogamy) in which the female gamete (e.g. egg cell) is significantly larger than the male gamete and is non-motile.

Question 21

uses of algae

Answer 21

1. half of CO₂ fixation on earth by photosynthesis
2. increase the level of dissolved oxygen in the atmosphere
3. primary producers of energy-rich compounds for aquatic life forms
4. 70 marine species are edible like laminaria, sargassum,porphyra
5. certain marine red and brown algae produce hydrocolloids like algin(b.a) and carrageen(r.a)
6. agar used in jellies and ice cream from Gelidium and Gracilaria
7. chlorella, unicell alga, rich in proteins, used as a food supplement

Question 22

hydrocolloids

Answer 22

water-holding substances

Question 23

three main classes of algae

Answer 23

Chlorophyceae
Phaeophyceae
Rhodophyceae

Question 24

the common name of Chlorophyceae

Answer 24

green algae

Question 25

pigments of grp 1

Answer 25

chlorophyll a,b

Question 26

stored food in grp 1

Answer 26

starch

Question 27

cell wall composition of grp 1

Answer 27

cellulose(inner) | pectose(outer)

Question 28

no. of flagella in grp 1

Answer 28

2-8

Question 29

size and position of flagella in grp 1

Answer 29

equal and apical

Question 30

habitat of grp 1

Answer 30

fresh, brackish, and saltwater

Question 31

body forms of grp 1

Answer 31

unicellular, colonial, or filamentous

Question 32

the shape of chloroplasts in grp 1

Answer 32

``` discoid plate-like reticulate spiral cup-shaped ribbon-shaped in diff species ```

Question 33

most members of grp 1 have one or more storage bodies called

Answer 33

pyrenoids

Question 34

pyrenoids

Answer 34

are located in the chloroplasts | proteinaceous centres surrounded by starch

Question 35

some algae(grp 1) may store food in the form of

Answer 35

oil droplets

Question 36

reproduction in grp 1

Answer 36

1. fragmentation 2. flagellated zoospores(from zoosporangia) 3. isogamy, anisogamy, oogamy

Question 37

examples of green algae

Answer 37

``` volvox spirogyra ulothrix chlamydomonas chara ```

Question 38

the common name of Phaeophyceae

Answer 38

brown algae

Question 39

major pigments in grp 2

Answer 39

chlorophyll a,c, xanthophyll, fucoxanthin

Question 40

stored food in grp 2

Answer 40

mannitol | laminarin

Question 41

cell wall composition in grp 2

Answer 41

cellulose(inner) | algin(gelatinous outer covering)

Question 42

no. of flagella in grp 2

Answer 42

2

Question 43

size and position of flagella in grp 2

Answer 43

unequal | lateral

Question 44

habitats of grp 2

Answer 44

primarily marine brackish, saltwater freshwater(rare)

Question 45

body forms of grp 2

Answer 45

simple branched filamentous forms(eg Ectocarpus) | to profuse branched forms(like kelps reaching even 100m)

Question 46

colour variation of grp 2

Answer 46

olive green to different shades of brown

Question 47

the protoplast of grp 2 contains

Answer 47

plastids centrally located vacuole nucleus

Question 48

parts of grp 2

Answer 48

holdfast-attaches itself to the substratum stipe-stalk like structure frond-leaf-like photosynthetic organ

Question 49

vegetative reproduction in grp 2

Answer 49

fragmentation

Question 50

asexual reproduction in grp 2

Answer 50

pear-shaped biflagellate zoospores having two unequal laterally attached flagella

Question 51

sexual reproduction in grp 2

Answer 51

isogamy anisogamy oogamy

Question 52

union of gametes of grp 2 takes place in

Answer 52

water or oogonium in oogamous species

Question 53

the shape of gametes in grp 2

Answer 53

pyriform(pear-shaped) | 2 unequal lateral flagella

Question 54

examples of brown algae

Answer 54

``` ectocarpus, dictyota laminaria sargassum fucus ```

Question 55

the common name of Rhodophyceae

Answer 55

red algae

Question 56

major pigments of grp 3

Answer 56

chlorophyll a,d | r-phycoerythrin

Question 57

habitats of grp 3

Answer 57

mostly marine and conc in warmer areas brackish water freshwater(some) both well-lighted regions and great depths

Question 58

stored food in grp 3

Answer 58

``` floridean starch (similar to amylopectin and glycogen in structure) ```

Question 59

cell wall composition of grp 3

Answer 59

cellulose pectin polysulphesters

Question 60

the body form of grp 3

Answer 60

the red thalli of most red algae are multicellular and some have complex body organisation

Question 61

vegetative reproduction in grp 3

Answer 61

fragmentation

Question 62

asexual reproduction in red algae

Answer 62

non-motile spores

Question 63

sexual reproduction in red algae

Answer 63

non-motile gametes(oogamy) | followed by complex post fertilisation developments

Question 64

examples of red algae

Answer 64

gelidium gracilaria porphyra