Cell Diversity - Unit 2 Flashcards
What is meant by a tissue
Group of similar cells, which carry out same function
Name 3 plant tissues
Dermal Tissue
Meristematic Tissue
Vascular Tissue
Describe: Dermal Tissue
Location: Found covering leaves, stems, and roots
Function: Protects plant
Adaptation: Thickened cell wall
Describe Meristematic Tissue
Location: Found usually in shoot and root tips
Function: initiates growth in plants and also allows for formation of new cells for growth/ development
Adaptation: Meristem cells can form specialised cells which allow for the plant to better adapt to it’s environment
Describe Vascular Tissue
Firstly remember we are focusing on Xylem and Phloem…
Location: Found in various regions, like leaf, stem and root.
(More specifically in the cortex pitch and mesophyll)
Function:
Xylem - Transports water and provides support.
(Xylem is on inner part of stem)
Phloem - Transports food from leaves to other parts of the plant i.e the root and also is responsible for message delivery to tell plant to bloom etc.
Adaptation:
Xylem -
Narrow
Has pits
Reinforced by lignin
Phloem -
Has a companion cell w/ many mitochondria.
This aids in sugar(food) transportation.
Name 3 Human/Animal Tissues
Connective Tissue
Nervous Tissue
Muscle Tissue
Describe Connective Tissue
Location: Blood, Ligaments, Adipose tissue
Function: joins and supports other body structure
Adaptation: Depending on where it is Connective Tissue can adapt.
E.g in :-
Bones: gets hard for support
Muscles: is flexible for movement
Connective Tissue is also in blood and is made of RBC and WBC and platelets
Describe Nervous Tissue
Location: in spinal cord, brain and nerves
Function: neurons (alias nerve cells) carry electrical impulses to and from brain and spinal chord.
Nervous Tissue is made of a group of nervous cells who carry out the same named function.
Adaptation: presence of a myelin sheath which insulates movement of electrical impulses
Describe Muscle Tissue
Location: skeletal muscle(i.e bicep or tricep)
Function: allows for movement by contracting and relaxing
Adaptation: their cells have a large many of mitochondria allowing to produce lots of necessary energy
What is Tissue Culture
Growth of cells in a sterile nutrient medium outside an organism
What is Sterile
Describes an environment free of micro-organisms
What is nutrient medium
Providing food to allow for growth of cells
What is the difference between In-vitro and In-vivo growth
In-vitro growth:- growth of cells outside the body in a artificial environment
Whereas..
In-vivo growth: growth of cells inside the body
Name 5 factors of a Successful Tissue Culture
Suitable temperature
Suitable pH
Oxygen Supply
Correct Vitamin and Mineral Supply
Correct Growth regulator and hormone Supply
Correct Nutrient Supply
Name the 3 main applications of a tissue culture
Plant Breeding(micro-
propagation)
Cancer Research
Skin Grafts
What is Micro-propagation
Growth of large number of cells from plant tissue or cells.
Describe the process in short
1) small no. of cells grown in culture
2) clump of cells called callus formed.
3) Mitosis divides callus into empro and empryoid and then becomes fully developed plant
Give the Advantages of Micro-propagation
Large number of plants produced in short amount of time
Plants are genetically identical
Cheap method to produce lots of planets
Give the Disadvantages of Micro-propagation
Disease can very easily spread due to them being genetically identical
Genetic variability
What is a Skin Graft?
Method to grow new skin for bad burns
Give the Advantages of Skin Grafting
New skin won’t be rejected by persons body as is genetically identical
No need to remove from other parts of the body (as skin can be simply grown there)
Give the Disadvantages of Skin Grafting
Cosmetic imperfections: grafts overtime may result in noticeable variations in pigment, texture in comparison to surrounding skin.
Graft Failure: Despite careful surgical procedures there’s an attached risk of the Graft failing leading to either a partial/complete loss of the Graft.
What is an Organ
A number of tissues which work together to carry out (sometimes) one or more function
Give 2 examples of Plant Organs
Roots
Leaves
