Lecture 10

Question 1

Opisthokonta

Answer 1

metazoans (animals), fungi and several additional microbial eukaryote lineages

Question 2

Disadvantages of being unicellular

Answer 2

Size is limited
Short life span
No division of labour

Question 3

Advantages of being unicellular

Answer 3

Rapid reproduction

Minimal resources required

Question 4

Unicellular Eukaryotes characteristics

Answer 4

Complete organisms
Mostly motile (can move)
Require moisture
Cause many diseases in humans and other animals

Question 5

Modes of Locomotion for unicellular

Answer 5

Flagella
Cilia (sing. Cilium)
Pseudopodia

Question 6

undulipodia

Answer 6

Cilia and Flagella are collectively referred to as undulipodia
morphologically the same

Cilia : numerous propel water parallel to the cell surface
Flagella: propels water parallel to the flagellum axis.

Question 7

Pseudopodia

Answer 7

projections of cell membrane
used for locomotion and phagocytosis

Endoplasm flows forward into pseudopod and solidifies into ectoplasm

Question 8

Endo and Ecto plasm

Answer 8

In unicellular organisms, used for pseudopodia
• Ectoplasm semi-solid outer layer
• Endoplasm inner fluid

Question 9

Taxonomy of Unicellular

Answer 9

• Flagellates
One or more flagella to propel cell
• Ciliates
Numerous cilia covering cell membrane
• Amoebas
Irregular shape
use pseudopodia
Plasma membrane can have test or shell

Question 10

Nutrition & Digestion of Unicellular organisms

Answer 10

• Autotrophs
‘self-feeding’ from environment
Plants, algae, many bacteria, unicellular eukaryotes
• Heterotrophs
Consumes other life
Animals, fungi, many bacteria, unicellular eukaryotes

* can also be both*

Question 11

Phagocytosis

Answer 11

Nutrition + digestion in unicellular organisms

Plasma membrane folds around the food particle
Lysosomes, small vesicles containing digestive enzymes, fuse with the food vacuole and pour their contents into it, starting digestion

Question 12

Cytostome

Answer 12

The cell mouth in many unicellular eukaryotes
Site of phagocytosis
Occurs in most cililates, many flagellates

Question 13

Cytoproct

Answer 13

Site on a unicellular eukaryote where undigestible matter is expelled
Occurs in many cililates

Question 14

Symbiosis

Answer 14

At least one species benefits; the other species may benefit.

Question 15

Mutualistic

Answer 15

both partners benefit

Question 16

Commensalistic

Answer 16

one partner benefits, no effect on the other

Question 17

Parasitic

Answer 17

one partner benefits at the expense of the other

Question 18

Reproduction For unicellular

Answer 18

ALL can reproduce asexually, some can reproduce asexually and sexually

Question 19

Reproduction in Paramecium

Answer 19

Binary fission(asexual)
Conjugation(sexual)

Question 20

Macro and Micronucleus in Paramecium

Answer 20

Macronucleus
• Metabolism, synthesis, development
• Paramecium cannot survive without macronucleus

Micronucleus
• Sexual reproduction
• Paramecium cannot reproduce without the micronucleus

Question 21

Binary Fission in Paramecium

Answer 21

Micronuclei divide mitotically
i.e. normal somatic cell division

Macronuclei divide amitotically
(nucleus and cytoplasm divide without formation of a spindle or condensation of chromosomes…. DNA doesn’t go through normal mitosis)

Question 22

Conjugation in Paramecium

Answer 22

temporary union of two individuals to exchange chromosomal material

Question 23

Reproduction in Apicomplexa

Answer 23

All endoparasites (lives within another organism(s)
• Life cycle includes both asexual and sexual reproduction 
• Sometimes use an intermediate host

Question 24

Plasmodium: Reproduction

Answer 24

• Definitive host = insect (sexual stage)

* Intermediate host = vertebrate (asexual stage)

Question 25

Schizogony vs Sporogony

Answer 25

• Schizogony (multiple fission)
sporozoite (n) —> many merozoites (n)

• Sporogony (special case of schizogony)
zygote (2n) —-> many sporozoites (n)