Classification Of Organisms

Question 1

Why have scientists designed classification systems

Answer 1

As a way to organize biodiversity.
Living organisms are divided into groups and subgroups according to similarities and shared characteristics

Question 2

Taxa

Answer 2

The groups into which organisms are classified

Question 3

The formal scientific classification of organisms is known as

Answer 3

Taxonomy

Question 4

What made classification systems complex for scientists

Answer 4

The structure of cells, microorganisms, evolution, genetics and molecular biology

Question 5

Two kingdom system

Answer 5

In 1758,a Swedish botanist, Carl Linnaeus classified living organisms into two kingdoms:Plantae(plants) and Animalia(animals)

Question 6

Linnaeus developed a hierarchical system of classification where 7 categories (taxa) under each kingdom where used.

Answer 6

Kingdom>phylum/division >class>family> genus >species

The above categories are based on shared physical properties within each group. Each level becomes even more specific. Organisms within the same family have more in common than organisms within the same order.

Question 7

A kingdom is subdivided into phyla for…. But in….. The term division is used

Answer 7

Animal, plants

Question 8

Biological classification

Answer 8

System used to sort out living things based on their similarities

Question 9

Carl Linnaeus used this system to separate

Answer 9

Plants that can make their own food, can’t move and are auto trophic and animals that can make their own food, can move and are hetero trophic

Question 10

Kingdom plantae characteristics

Answer 10

Can’t move
During daytime they are involved in photosynthesis as they need sunlight and obtain carbon dioxide and liberate oxygen
Unlimited growth for certain plants
Excretory and nervous system aren’t present
They reserve food material(starch)
Reproduce asexually(not direct contact) and Fertilization takes place with the help of agents like wind, water etc..
Plant cells don’t have Centrosomes so they may have inorganic crystals

Question 11

Kingdom Animalia characteristics

Answer 11

Definite body shape and no branches
Move place to place but can’t make their own food.
Release carbon dioxide and take in oxygen from plants
Can’t partake in photosynthesis
Grow a certain length, size and width
Excretory and nervous system are advanced
Reserve food materual(glycogene)
Centrosomes are present and have organic crystals

Question 12

Disadvantages of the two kingdom system

Answer 12

Unicellular organisms do not fit in either of the kingdoms. This system does not provide a separate distinction for such organisms.

It grouped the photosynthetic organisms (plants) and the non-photosynthetic organisms (fungi) in the same kingdom, Plantae.

No distinction between the eukaryotes and prokaryotes.

Question 13

Five kingdom system

Answer 13

The two kingdom was expanded into a five kingdom system as more scientific information about organisms was obtained. In 1969,Robert Whitaker proposed the five kingdom system

Question 14

5 kingdoms

Answer 14

Monera(bacteria)
Protista
Fungi
Animalia
Plantae

Question 15

What criteria was used to classify organisms into the five kingdoms

Answer 15

Body structure - unicellular/multicellular/colonies

Cell structure - presence/absence of a nucleus:organelles(chloroplasts)

Composition of cell wall– cellulose/chitin/no cell wall

Motility - mobile /immobile

Mode of nutrition - autotroph/heterotroph

Method of reproduction - binary fission/asexual/sexual

Question 16

Prokaryotes

Answer 16

Organisms that don’t have a true nuclei
Their DNA is not enclosed by a nuclear membrane and therefore occurs free in the cytoplasm
No true organelles in the cytoplasm
Monera are prokaryotes

Question 17

Eukaryotes

Answer 17

Organisms with cells that have true nuclei.
Their DNA is enclosed by a nuclear membrane and therefore occurs inside the nucleus
True organelles occur in the cytoplasm. All Protista, fungi, Plantae and Animalia are all eukaryotes

Question 18

Characteristics of kingdom monera

Answer 18

Unicellular have no true nuclei and therefore prokaryote
Bacterium cell is surrounded by cell wall
Some bacteria are autotroph ice and produce their own organic substances by photosynthesis
Majority of the bacteria are heterotrophic and cannot produce their own organic substances. Heterotrophic bacteria are either parasites or saprophytes, or they live Mutualistically with other organisms.
Reproduction occurs asexually by binary fission whee a single cell divides into two cells of identical DNA composition

Question 19

Parasitic

Answer 19

Dependent on living organic matter for food where organisms live together (symbiosis) and one benefits and the other is harmed.

Question 20

Saprophytic

Answer 20

Dependent on dead organic matter for food

Question 21

Mutualistic

Answer 21

Living together with other organisms so that both can benefit from the relationship (a type of symbiosis)

Question 22

Characteristics of kingdom Protista

Answer 22

Distinguished into 3 groups :
Protozoa-animal like, unicellular and heterotrophic organisms
Algae - plant like. Autotrophic (have chlorophyll and can photosynthesise)
Slime moulds and water moulds fungus like organisms

Subgroups :
Chrysophytes:Chrysophytes are agroup of algae with yellowish green to golden brown pigments.They are usually found in freshwater and marine habitats with low calcium(desmids)

Dinoflagellates-Dinoflagellates aresingle-celled aquatic organisms with two flagella found in fresh and saltwater. Usually photosynthesise and the color they appear is dependent on the key pigments in their cell: red,, brown, green.

Euglenoids:Euglenoids aresingle-celled protists
Instead of the cell wall, a protein-rich cell membrane known as pellicle is present.

They bear two flagella on the anterior end of the body.

A small light-sensitive eye spot is present.

Question 23

Magnification of cells

Answer 23

The formula to calculate magnification is: magnification = size of image / real size of object12. This equation can be rearranged to calculate the actual length of the cell and the magnification used as well as the length of the image3. To calculate magnification using the formula in micrometres, convert the measurement of the cell from mm into micrometres4

Question 24

Types of monera

Answer 24

Coccus(circles)
Vibro(pea shaped)
Bacillus (oval)
Spirillum(, spirals)

Question 25

Protista moves by means of

Answer 25

Flagella, cilia and cyclosis

Question 26

Reproduction for Protista

Answer 26

Asexual by binary fission and they live in moist environment as they are aquatic

Question 27

Characteristics of fungi kingdom

Answer 27

Distinguished into 3 groups:
Yeast, mushrooms and moulds.

Yeasts are unicellular while mushrooms and moulds are multicellular.
All fungi have true nuclei and are therefore eukaryotic.
Cell walls containing cellulose and chitin
Fungal body consists of a mass of branched filaments or hyphae
Fungi have no chlorophyll and are therefore heterotrophic.
Most fungi are saprophytes and live off dead organic plant and animal Matter like bread mould and mushroom.
Some are parasites and feed on living matter causing athletes foot
And some are Mutualistic
Reproduction occurs :
Unicellular fungi :asexually by binary fission
Multicellular fungi : asexually by means of spores during favorable conditions
Sexually by means of gametes during unfavorable conditions

Question 28

Plant kingdom is divided into 4 divisions

Answer 28

Bryophytes-mosses
Pteridophytes-fern
Gymnosperms-conifers
Angiosperms-flowering plants

Question 29

Kingdom Animalia is divided into 9 phylum

Answer 29

Porifera-sponges
Cnidaria-jellyfish
Platyhelminthes-flatworms
Nematoda-round worms
Annnelida-earth worms
Mollusca-snails
Echinodermata-starfish

Question 30

The used it common names for living organisms may cause confusion because the same organisms in different regions have different names or same name given to different species or scientists speaking different languages for this reason

Answer 30

A binomial (double-name) system was designed by Carl Linnaeus for the naming of living organisms, based in Latin as scientists throughout the world used it.

Question 31

How to make a scientific name

Answer 31

The genus name is written with a capital letter and the species with a small letter then underlined afterwards.

Question 32

Dichotomy

Answer 32

Divided into two parts. It was a key used to consist with a series of options that lead to the user to the correct name of an organism

Question 33

mutualistic

Answer 33

living together with other organisms so that both benefit from the relationship. a type of symbiosis

Question 34

monera- reproduction happens asexually

Answer 34

binary fission where a singl cell divides into 2 identical cells of the same dna composition.

Question 35

species

Answer 35

group of related organisms that interbreed and produce fertile offspring.

Question 36

cambrian explosion

Answer 36

early forms of most animal groups

Question 37

mass extinction

Answer 37

when many species dissapear over the same period of time

Question 38

due to physical causes like

Answer 38

climate change; volcanic eruptions and continental drift

Question 39

moulds

Answer 39

hard part of an organism trapped in sediment