Transport in animals

Transport in animals

Blood

* Blood is the medium for transport in animals

* Blood consists of 4 components

- plasma (55% of blood)

- red blood cells + white blood cells + platelets (make up 45% of blood)

Plasma

* Plasma is the liquid which carries the components in the blood,

* e.g. cells, platelets, amino acids, hormones etc.

* Plasma is important for the transport of carbon dioxide, digested food, urea, hormones and heat energy

Red blood cells

Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration

They have specific structural features which make them suited to this task:

White Blood Cells

* White blood cells are part of the body’s immune system, defending against infection by pathogenic microorganisms 

* There are two main types, phagocytes and lymphocytes .

Phagocytes

* Phagocytes have a sensitive cell membrane that can detect chemicals produced by pathogens.

* Once they encounter the pathogenic cell, they will engulf it and release digestive enzymes to digest it

* They can be easily recognized by their multi-lobed nucleus and their ability to change shape easily

* Phagocytes do this to all pathogenic cells they encounter and as such it is described as a non-specific immune response .

Lymphocytes

* Produce antibodies to destroy pathogenic cells and antitoxins to neutralize toxins released by pathogens

Mechanisms carried out by lymphocyte

* All cells have proteins and other substances projecting from their cell membrane and are called antigens.

* Lymphocytes can ‘read’ the antigens on the surfaces of cells and recognise any that are foreign

* They then make antibodies which are a complementary shape to the antigens

* The antibodies attach to the antigens and cause agglutination (clumping together)

* This means the pathogenic cells cannot move very easily

Mechanisms carried out by lymphocyte continued...

* At the same time, chemicals are released to signal to phagocytes that there are cells present that need to be destroyed

* The initial response of a lymphocyte encountering a pathogen for the first time and making specific antibodies for its antigens can take a few days, during which time an individual may get sick

* Lymphocytes that have made antibodies for a specific pathogen for the first time will then make ‘memory cells’ that retain the instructions for making those specific antibodies for that type of pathogen

* This means that, in the case of reinfection by the same type of pathogen, antibodies can very quickly be made in greater quantities and the pathogens destroyed before they are able to multiply and cause illness

* This is how people can become immune to certain diseases after only having them once

Multiple Choice

Which of the following is the name for a micro-organism that can cause disease?

• Pathogen

• Antibodies

• B-cells

• Lymphocyte

Multiple Choice

Phagocytes kill pathogens by

• engulfing and digesting them

• producing antibodies

Multiple Choice

Chemicals on the surfaces of pathogens , which are recognsied as foreign by the body.

• antibodies

• antibiotics

• antigens

Multiple Choice

Immune system recognises which part of a pathogen?

• active site

• antibiotc

• antibody

• antigen

Multiple Choice

chemical secreted by lymphocytes, which attach to antigens and help to destroy them

• antibiotics

• antibodies

• both antibodies and antibiotics

• none of these

Multiple Choice

Blood has how many parts?

• 1
• 2
• 3
• 4

Multiple Choice

Which leukocyte produces antibodies?

• lymphocytes
• monocytes
• eosinophils
• basophils

Multiple Choice

Antibodies binding to antigens on RBCs causes a clumping known as __________

• agglutination
• coagulation
• clotting cascade
• hemolysis

Multiple Choice

Which cell releases antibodies to the blood?

• phagocytes

• lymphocytes

• platelets

Multiple Choice

Which cell engulfs and digests bacteria/pathogens?

• lymphocytes

• phagocytes

• platelets

Multiple Choice

What is plasma?

• only white blood cells

• only red blood cells

• fluid part of blood

• hemoglobin

Multiple Choice

What is blood made of?

• oxygen and plasma

• red blood cells and white blood cells

• plasma, red blood cells, white blood cells, and platelets.

• plasma and platelets

Multiple Choice

What is the function (job) of the plasma?

• To release antibodies to fight infections.

• To transport oxygen around the body.

• To carry dissolved nutrients and sugars.

• To transport oxygen around the body.

Multiple Choice

What is the function (job) of the white blood cells?

• To transport oxygen around the body.

• To carry dissolved sugars.

• To clot and cover wounds like cuts and grazes.

• To release antibodies to help destroy infections.

Multiple Choice

What causes the blood to be the distinct red colour?

• Haemoglobin

• Glucose

• Hormones

• Oxygen

Multiple Choice

What carries oxygen around the body?

• Plasma

• Red Blood Cells

• Platelets

• White Blood Cells

Multiple Choice

What makes up around 55% of the blood?

• Plasma

• Red Blood Cells

• White Blood Cells

• Platelets