Specialised Cells 6.4

Question 1

Specialised Cells

Answer 1

These are cells that are differentiated so they can perform a specific function in the body.

Question 2

Organisation in organisms

Answer 2

Specialised cells, Tissues, Organs, Organ Systems, Whole Organism

Question 3

Give examples of specialised cells in animals

Answer 3

Erythrocytes, Neutrophils and Sperm Cells

Question 4

Give examples of specialised cells in plants

Answer 4

Palisade cells, Root Hair cells and Guard Cells

Question 5

Erythrocytes

Answer 5

These are red blood cells and have to deliver oxygen around the body.
They are a biconcave shape that increases their SA: V ratio so more oxygen can diffuse in.
They have no nucleus and few organelles so they can maximise the storage of haemoglobin so more oxygen can bind and be transported
They are flexible so they can squeeze through capillaries

Question 6

Neutrophils

Answer 6

These are a type of white blood cells in the immune system and attack pathogens.
They have a multilobed nucleus which makes it easier for them to squeeze into small gaps at the site of infection
They have many lysosomes that contain hydrolytic enzymes so they can break down pathogens

Question 7

Sperm

Answer 7

These are gametes and contain genetic material to bind to the ovum.
They have the acrosome on the head of the sperm which contains a digestive enzyme to break down the outer layer of the ovum and penetrate it.
They also have a flagellum which propels them forward so they can swim to the ovum
They have a lot of mitochondria as they need to respire in order to be able to swim

Question 8

Palisade Cells

Answer 8

These are present in the mesophyll.
They contain many chloroplasts so they can photosynthesis a lot, these chloroplasts can move around to absorb as much light as possible
They are rectangular shaped so they can be [lacked close together.
They have a big vacuole to maintain turgor pressure
They have thin cell walls to maximise the rate of diffusion

Question 9

Root Hair Cells

Answer 9

These cells uptake water and minerals and have long extensions called root hairs that increase the SA for maximised uptake.

Question 10

Guard Cells

Answer 10

These control the opening of the stomata and are important for photosynthesis and transpiration. When they lose water, they become crenated and the stomata will close. When they absorb water, they become swollen and the stomata will open. The cell wall of the guard cell is thicker on one side than the other so it doesn’t change shape symmetrically.

Question 11

Tissue

Answer 11

A collection of differentiated cells that carry out specialised functions.

Question 12

What are the main categories of tissue?

Answer 12

Nervous tissue, Epithelial tissue, Muscle tissue and Connective tissue

Question 13

Examples of animal tissue

Answer 13

Squamous epithelium, Ciliated epithelium, Cartilage, Muscle

Question 14

Examples of plant tissue

Answer 14

The epidermis, Xylem Tissue, Phloem Tissue

Question 15

Squamous Epithelium

Answer 15

Lines the lungs and is composed of squamous epithelial cells. Only one cell thick which maximised the diffusion of oxygen in the lungs

Question 16

Ciliated Epithelium

Answer 16

It lines the trachea and is composed of ciliated epithelial cells. It has small hair-like structures called cilia that move in a rhythmic manner and swipe mucus away from the lungs. Goblet cells can also be present in the tissue and they release mucus to trap unwanted bacteria so it doesn’t enter the lungs.

Question 17

Cartilage

Answer 17

It is a connective tissue that prevents the ends of bones rubbing together and it is flexible. It contains both elastin and collagen fibres and is made up of chondrocyte cells

Question 18

Muscle

Answer 18

Muscle needs to contract in order to move bones in the skeleton, it contains muscle fibres like myofibrils

Question 19

Epidermis

Answer 19

This covers the plant and has a waxy cuticle layer to reduce the loss of water. They are tightly packed and contain stomata needed for CO2 in and o2 and water out.

Question 20

Xylem

Answer 20

Type of vascular tissue. Transports water and minerals throughout the plant, they are made of elongated dead cells that are reinforced with lignin on the outside.

Question 21

Phloem

Answer 21

Type of vascular tissue. Transports nutrients like sugar from stem and leaves to where it is needed. Its cells are alive and have sieve tube plates on the end of each one.

Question 22

Organs

Answer 22

Collection of tissues made up of differentiated cells that are adapted to perform specific functions like the heart pumps blood etc…

Question 23

Organ Systems

Answer 23

Coordinated number of organs working together to carry out specific functions. E.g the digestive system or lymphatic system