6.4 Cellular organisation Flashcards
1
Q
Why do cells group together?
A
- to form tissues with the purpose of performing a common function
2
Q
What are two examples of plant tissues?
A
- phloem
- xylem
3
Q
Organs are …
A
- groups of
tissues which work together to perform a wider function
4
Q
Organ system is …
A
- composed of many organs which work together to perform an essential life function
5
Q
Function of xylem is …
A
- transport water and minerals as well as provide structural support
6
Q
Structure of xylem is …
A
- long cylinders made of dead tissue with open ends
- xylem vessels are thickened
with a tough substance called lignin
7
Q
What do xylem cells consist of?
A
- parenchyma, fibres and vessels are produced by meristem cells which produce smaller cells that elongate
8
Q
Function of phloem is …
A
- tubes made of living cells which are involved in translocation which is the
movement of food substances and nutrients from leaves to storage organs and
growing plants of the plant
9
Q
What does meristem tissue do in phloem tissue?
A
- produces cells that elongate and line up end-to-end to form a long tube
- Their ends do not break down completely but produce perforated structures known as sieve plates
10
Q
What are companion cells?
A
- metabolically active
- located next to sieve plates and are involved in mediating the movement of
photosynthesis products upwards and downwards in the tubes
11
Q
What is epithelial tissue?
A
- sheet of cells that serves as a lining/cover a surface
12
Q
What are the two types of epithelial tissue?
A
- squamous
- ciliated
13
Q
Squamous is …
A
- are smooth, flat and very thin, fitting closely together to create
a smooth surface - such as the lining of blood vessels and cheeks
14
Q
Ciliated is …
A
- composed of column shaped cells containing cilia which form the lining of structures such as trachea and bronchi
- found in the oviducts
15
Q
Cilia is …
A
- move together to move the mucus produced by goblet cells along
