IIITn Cells Flashcards
Arrange these terms in order of size from smallest to largest: organism tissue organ cell molecule organelle organ system
molecule → organelle → cell→ tissue → organ → organ system → organism
Define a cell
The simplest living unit of all life forms
e.g. guard cell, goblet cell
Define a tissue and give an example of an animal tissue and a plant tissue
An collection of similar cells working together to carry out a specific function
Examples:
- animal tissue: ciliated epithelium, connective tissue, muscle tissue and nervous tissue
- plant tissues: xylem, phloem
Define an organ and give an example of an animal organ and a plant organ (3)
A collection of different tissues working together to carry out specific functions
Examples:
- animal organs : stomach, pacreas, eye, skin, liver, heart
- plant organs: leaf, flower, root
Define an organ system
A collection of different organs working together to carry out specific functions
E.g. digestive system consists of stomach, pancreas, small and large intestine
Give 3 examples of specialised cells found in animals
Red blood cell (found in the blood)
Motor neurone (found in the nervous system)
Cardiac muscle cell (only found in the heart)
Ciliated epithelial cells (found in the trachea, bronchi and bronchioles)
Give 3 examples of specialised cells found in plants
root hair cell (in the root TIPS)
guard cell (in the lower epidermis)
palisade mesophyll cell (in the leaf)
Give 3 ways in which a sperm cell (spermatocyte) is specialised for function?
Head only contains half the number of chromosomes in the nucleus (to enable the chromosome number to be kept correct after fertilisation)
Middle part of the cell has many mitochondria (to produce ATP used by the cell to enable it to swim)
Tail is a long extension to the cell (to enable it to move by propulsion)
Give 4 ways in which a red blood cell (erythrocyte) is specialised for function?
Shape is a biconcave disc (to increase the surface area to volume ratio to take up more oxygen by diffusion)
Biconcave shape also allows RBC to squeeze through the capillaries
No nucleus or mitochondria (to enable it to form a biconcave shape)
Contains a special protein called haemoglobin (to bind with oxygen to form oxyhaemoglobin
Give 4 ways in which the root hair cell is specialised for function?
Long extension to the cell wall, cell membrane and cytoplasm (to increase its surface area)
Thin cell wall (to reduce the distance water has to travel to enter the cell by osmosis)
Large permanent vacuole (to hold more water)
High number of mitochondria (to produce ATP for active uptake on mineral ions from the soil)
Give an example of an organ in a plant and an animal
Plant organs = leaf, flower
Animal organs = stomach, uterus, brain, liver, pancreas, eye
Give an example of an organ system in a plant and an animal
Plant organ systems = root system, shoot system
Animal organ systems = digestive system, reproductive system, circulatory system
How would you calculate the area of a circle?
Area = π r2
If you want to observe a living specimen which type of microscope must you use?
Light microscope
You can not use an electron microscope as EMs requires the specimen to be placed in a vacuum so only dead specimens can be observed
Name 2 sub-cellular structures that can be seen with an electron microscope but not a light microscope.
Ribosomes
Plasmids
Other than plant cells which other cells have a rigid cell wall and chloroplasts?
Algae e.g. seaweed
Plant cell walls and algal cell walls are both made from the same chemical. What is this chemical?
Cellulose
