Living Things in Nature

Question 1

Who proposed the Five Kingdom Classification

Answer 1

R.H. Whittaker (1969)
-The kingdoms were defined as Monera, Protista, Fungi, Plantae, and Animalia

Question 2

Kingdom Monera (Bacteria)

Answer 2

-Bacteria are the sole members of this Kingdom

Question 3

Classification of bacteria based on shape

Answer 3

-Coccus (Cocci): Spherical shaped bacteria
-Bacillus (Bacilli): Rod-shaped bacteria
-Vibrium (Vibrio): Comma shaped bacteria
-Spirillum (Spirilla): Spiral shaped bacteria

Question 4

Bacterial modes of Nutrition

Answer 4

-Some may be autotrophic
-They may be photosynthetic autotrophic or chemosynthetic
-The vast majority of bacteria are heterotrophic

Question 5

Archeabacteria

Answer 5

Bacteria that live in some of the harshest habitats such as extreme habitats

Question 6

Eubacteria (True bacteria)

Answer 6

Characterized by the presence of a rigid cell wall, and if motile a flagellum

Question 7

Mycoplasmas

Answer 7

-Organisms that completely lack a cell wall

Question 8

Kingdom Protista

Answer 8

Protists are single-celled or unicellular organisms
-Made up of eukaryotic cells
-cell structure is complex with a well-defined nucleus
-Protophyta: Plant-like protists
-Protozoa: Animal-like protists
-Slime Mould: Fungi-like protist
Protists reproduce asexually and sexually by a process involving cell fusion and zygote formation

Question 9

Phylum Protophyta: Chrysophytes

Answer 9

-Includes diatoms (microscopic single-celled algae) and golden algae (desmids)
-Found in freshwater and marine environments
-Most of them are photosynthetic
-Walls are embedded with silica.

Question 10

Silica

Answer 10

A protective outer covering made of Silicon Dioxide (SiO₂), highly durable and can perlite in sedimentary deposits for millions of years

Question 11

Phylum Protophyta: Dinoflagellates

Answer 11

-Mostly marine and photosynthetic
-Cell wall has stiff cellulose plates on the outer surface
-Most of them have two flagella, one longitudinal and one transverse
Ex: Red Dinoflagellate, Gonyaulax

Question 12

Euglenoids

Answer 12

-Freshwater organisms found in stagnant water
-Instead of a cell wall they have a protein-rich layer called a pellicle that makes their body flexible
-Have two flagella, long and short respectively
-Photosynthetic in the presence of sunlight
-Heterotrophs in the absence of sunlight

Question 13

Phylum Protozoa: Rhizopoda (Amoeboid Protozoans)

Answer 13

-Live in freshwater, seawater or moist soil
-Move and capture their prey by putting out pseudopodia (false feet)
-Marine forms have silica shells on their surface
Ex: Amoeba

Question 14

Phylum Protozoa: Ciliophora (Ciliated Protozoans)

Answer 14

Aquatic, actively moving organisms because of the presence of thousands of cilia
-Contain cavity (gullet) that opens to the outside of the cell surface
Ex: Paramecium

Question 15

Phylum Protozoa: Mastgiophora (Flagellated Protozoans)

Answer 15

-Either free-living or parasitic
-Contain flagella
-Cause diseases like sleeping sickness
Ex: Trypanosoma

Question 16

Phylum Protozoa: Sporozoans (Sporozoan)

Answer 16

Have an infectious spore-like stage in their life cycle
-Ex: Plasmodium (malarial parasite) which causes malaria

Question 17

Slime Moulds (Fungi like Protist)

Answer 17

-Saprophytic Protist that moves along decaying twigs and leaves engulfing organic materials
-In suitable conditions, they form an aggression called plasmodium which may grow and spread over several feet
-In unsuitable conditions, the plasmodium differentiates and forms fruiting bodies bearing spores at their tip
-Spores are extremely resistant and survive for many years

Question 18

Kingdom Fungi (Mycota)

Answer 18

-Prefer to grow in warm humid places
-Except yeast which are unicellular, fungi are filamentous.
-Their bodies consist of long, slender, thread-like structures called hyphae
-Some hyphae are continuous tubes filled with multinucleated cytoplasm called coenocytic hyphae
-Others have septate or cross walls in their hyphae
-Cell walls composed of chitin and polysaccharides

Question 19

Fungal Modes of Nutrition

Answer 19

-Most fungi are saprophytes, heterotrophic fungi that absorb soluble organic matter from dead structure
-Parasites are fungi that depend on living plants and animals
-They can also live as symbionts in association with algae as lichens and with roots of higher plants as mycorrhiza

Question 20

Reproduction in Fungi

Answer 20

-Reproduction can take place by vegetative means - fragmentation, fission, and budding
-Asexual reproduction is by conidia or sporangiospores or zoospores
-Sexual reproduction is by oospores ascospores and basidiospores

Question 21

Sub-kingdom Fungi: Myxomycota (False Fungi)

Answer 21

False fungi because they lack mycelium

Question 22

Sub-kingdom Fungi: Phylum Eumycota (True Fungi)

Answer 22

Treu fungi because they have mycelium
-The morphology of the mycelium, mode of spore formation, and fruiting bodies for the basis for the division of the kingdom into various classes

Question 23

Kingdom Fungi: Phycomycetes

Answer 23

-Found in aquatic habitats and on decaying wood in moist and damp places
-Mycelium is aseptate and coenocytic
-Asexual reproduction takes place by zoospores (motile) or by aplanospores (non-motile)
-Spores are endogenously produced in sporangium
Ex: Mucor, Rhizopus (bread mould), Albugo (parasitic fungi)

Question 24

Kingdom Fungi: Phylum Ascomycetes (Sac Fungi)

Answer 24

-Unicellular
-Saprophytic, decomposers, parasitic or coprophilous (growing on dung)
-Mycelium is branched and septate
-Asexual spores are conidia produced exogenously on the special mycelium called conidiophores
-Sexual spores are called ascospores and are produced endogenously in sac-like asci (singular ascus)
-Asci are arranged in different types of fruiting bodies called ascocarp
Ex: Aspergillus, Claviceps, Neurospora

Question 25

Kingdom Fungi: Phylum Basidiomycetes

Answer 25

-They grow in soil, on logs and tree stumps, and in living bodies as parasites
-Mycelium is branched and septate
-No asexual spores
-Vegetative reproduction is by fragmentation
-Basidiospores are exogenously produced on the basidium
-Basidia are arranged in fruiting bodies called basidiocarps
Ex: Agaricus (mushroom), Ustilago (smut), and Puccinia (rust fungus)

Question 26

Kingdom Fungi: Phylum Deuteromycetes (Imperfect Fungi)

Answer 26

-Known as imperfect fungi because only the asexual or vegetative phases of these fungi are known

Question 27

Kingdom Plantae

Answer 27

-Includes all eukaryotic chlorophyll-containing organisms
-Few members are partially heterotrophic
-Have a eukaryotic structure, prominent chloroplast, and cell wall made of cellulose
-Includes algae, bryophytes, pteridophytes, gymnosperms, and angiosperms

Question 28

Alternation of Generation

Answer 28

The life cycle of plants has two distinct phases - the diploid saprophytic and haploid gametophytic- that alternate with each other
-The lengths of the haploid and diploid phases and whether those phases are free-living or dependent on others, vary among different groups in plants

Question 29

Kingdom Animalia

Answer 29

-Heterotrophic eukaryotic organisms, multicellular, and lack cell wall
-Digest their food in an internal cavity and store food reserves as glycogen or fat
-Mode of nutrition is holozoic by ingestion of food
-Sexual reproduction is by copulation of male and female followed by embryological development
Split into Invertebrata (creatures with no backbone) and Vertebrata (creatures with backbone)

Question 30

Viruses

Answer 30

Viruses did not find a place in classification since they are not truly ‘living’
-Non-cellular organisms
-Characterized by an inert crystalline structure outside the living cell
-once they infect the cell, they take over the machinery of the host cells to replicate themselves
-Inert outside their specific host cell (obligated protist)

Question 31

Bacteriophages

Answer 31

Viruses that infect bacteria

Question 32

Viroids

Answer 32

Free RNA that lacks a protein coat

Question 33

Lichens

Answer 33

Symbiotic associations i.e. mutually useful associations between algae and fungi. The algal component is known as photobiont, and the fungal component as mycobiont, which are autotrophic and heterotrophic
-Algae prepare food for fungi and fungi provide shelter and absorb mineral nutrients and water for their partner