Specialised Cells

Question 1

definition of differentiation

Answer 1

the process of a cell becoming differentiated. involves the selective expression of genes in a cell’s genome

Question 2

definition of a tissue

Answer 2

a collection of differentiated cells that have a specialised function or functions in an organism

Question 3

definition of an organ

Answer 3

A group of specialised tissues working together to carry out a specific function

Question 4

definition of an organ system

Answer 4

​A group of specialised organs working together to carry out a specific function.

Question 5

definition of a stem cell

Answer 5

undifferentiated cells with the potential to differentiate into any specialised cell types of the organism

Question 6

definitions of a specialised cell

Answer 6

cells designed to carry out a specific function e.g. red blood cells and nerve cells in animals and root hair cells in plants

Question 7

shape

adaptations of erythrocytes (red blood cells) and how they help to carry out functions

Answer 7

flattened biconcave shape
- increase surface area to volume ratio

no nuclei
- increases the amount of room for haemoglobin

flexible
- are able to squeeze through narrow capillaries

Question 8

nucleus

why do they have granular cytoplasm?

adaptations of neutrophils ( a type of white blood cell) and how they help to carry out functions

Answer 8

have a multi-lobed nucleus
- makes it easier to squeeze through small gaps to reach site of infection

granular cytoplasm contains many lysosomes
- contain enzymes used to attack pathogens

Question 9

tail

enzymes
which cellorganelle do they have lot of?

adaptations of sperm cells and how they help to carry out functions

Answer 9

have a tail or flagellum
- capable of movement

lots of mitochondria
- supply the energy needed to swim

head of sperm contains digestive enzymes
- released to digest protective layers around the ovum and allow the sperm to penetrate, leading to fertilisation

Question 10

what do they contain? what can they do?

shape
thin
size of vacuole

adaptations of palisade cells and how it helps to carry out functions

Answer 10

contain chloroplast
- to absorb light for photosynthesis

rectangular box shape
- can be closely packed to form a continuous layer

have thin cell wall
- increase rate of diffusion of carbon dioxide

have a large vacuole
- to maintain turgor pressure

chloroplasts can move within
- to absorb more light

Question 11

adaptations of root hair cells and how it helps to carry out functions

Answer 11

near tips of roots with extensions called root hair cells
- increases surface area to maximise uptake of water and minerals

Question 12

shape

stomata

adaptations of guard cells and how it helps to carry out functions

Answer 12

become less swollen and change shape when they lose water
- to close them to stop any further water loss

form small openings called stomata
- necessary for carbon dioxide to enter the plant for photosynthesis

Question 13

thin

adaptations of squamous epithelium and how it helps to carry out functions

Answer 13

very thin due to the squat or flat cells that make it up and is only 1 cell thick
- forms the lining of the lungs and allows rapid diffusion of oxygen into the blood

Question 14

hair like structures

globlet cells

adaptations of ciliated epithelium and how it helps to carry out its function

Answer 14

they have hair-like structures called cilia that move in a rhythmic manner
- line the trachea to waft mucus away from the lungs

globlet cells are present
- are released to trap unwanted particles present in the air e.g. stopping bacteria from reaching the alveoli.