Download 3 The cell as the basic unit of life

3 The cell as the basic unit of life
Class Practice
3.1 Discovery of cells
3.2 Microscope
A. A objective
B clip
C stage
D condenser
E mirror
B.
F
G
H
eyepiece
course adjustment
fine adjustment
I
1.
2.
3.
4.
5.
6.
revolving nosepiece
G
D
E
C
B
A
7.
8.
9.
I
F
H
3.3 Basic structure of a cell
A. 1. a
2. c
3. c
4. b
5.
6.
7.
8.
9.
a
c
a
c
a
B.
1.
2.
3.
4.
5.
6.
7.
8.
cell membrane
cytoplasm
mitochondria
chloroplasts
cell wall
nucleus
vacuole
chromosomes
3.4 The similarities and differences between plant and animal cells
3.5 The cell as a basic unit of life
1.
2.
nucleus  cell  tissue  organ  system  organism
(i) E
(ii) C, D
(iii) D
(iv) A
(v) B
Exam Practice
A. Multiple Choice Questions
1. C
2. C
3. B
4. C
5. D
6. D
7. C
8.
B.
C
Structured Questions
1. (a) A cell wall
B cell membrane
C nucleus
D cytoplasm
E chloroplast
F
vacuole
(b) (i)
It protects and supports the cell.
It resists the entry of excess water into the cell.
(ii) It controls the normal activities of the cell.
(c) Photosynthesis
(d) Mitochondria. Respiration occurs in mitochondria to release energy.
2.
1
(e) cell 1 = ―― = 100
0.01
2
cell 2 = ――― = 400
0.005
(a) 50X
(b) 10 × 40 = 400X
(c) (i) They look bigger.
(ii) A smaller area of the slide can be observed.
C.
STS Connections
(a) Tissue level and system level. Similar cells group together to form a
tissue. Several different tissues form a functional unit called organ.
Several organs and tissues working for the same ultimate functions form
a system.
(b) organ level
(c) The skin cells degenerate continuously and those dead cells are pushed
towards the skin surface where they are rubbed off or detach automatically.
His skin still functions well because many skin cells can be recovered by
cell division.