2.5 d) Defence Against Parasitic Attack

Question 1

Immune response in mammals has both ___ and __-___ effects.

Answer 1

specific, non-specific

Question 2

Non-specific defences of mammals include…

Answer 2

physical barriers,
chemical secretions,
inflammatory response,
phagocytes,
natural killer cells

Question 3

Phagocytes and natural killer cells are examples of what.

Answer 3

non-specific defences in mammals

Question 4

Epithelial tissue blocks…

Answer 4

the entry of parasites

Question 5

Hydrolytic enzymes in ___, ___ and ___ destroy bacterial cell walls.

Answer 5

mucus, saliva, tears

Question 6

What type of enzyme in mucus, saliva and tears destroys bacterial cell walls?

Answer 6

hydrolytic

Question 7

The low __ environments of the secretions of the ___, ___ and ___ glands denature the ___ proteins of ___.

Answer 7

pH, stomache, vagina and sweat, cellular, pathogens

Question 8

Describe the inflammatory response.

Answer 8

cells that are injured by cut/wound release signalling molecules, which increase blood flow to the site, bring more antimicrobial proteins and phagocytes.

Question 9

Describe the inflammatory response.

Answer 9

When skin is damaged (eg cut or wound), damaged cells release signal molecules (called cytokines) which trigger an increase in blood flow to the area, bringing more antimicrobial proteins and phagocytes

Question 10

What are phagocytes?

Answer 10

White blood cells with a non-specific role in defence

Question 11

Phagocytes are ___ blood cells with a __-___ role in defence.

Answer 11

White, non-specific

Question 12

Phagocytes arrive at the site of ___, and ___ parasites by enfolding their ___ ___ around the parasite.

Answer 12

infection, engulf, plasma membrane

Question 13

Once engulfed, the parasite is brought into the ___ in a ___.

Answer 13

phagocyte, vacuole

Question 14

Phagocytes contain, ___ (which are filled with ___ enzymes).
The lysosome ___ with the ___, and the parasite is ___.
This process is called ___.

Answer 14

lysosomes, digestive.
fuses, vacuole, digested.
*(parasite or pathogen or infected cell)
phagocytosis.

Question 15

Describe the 3 steps to phagocytosis.
1.
2.
3.

Answer 15

1. phagocytes arrive at the site of infection
2. phagocytes engulf parasite by enfolding them with their plasma membrane
3. lysosome fuses with vacuole and parasite is digested.

Question 16

Natural killer cells can ___ and ___ to cells infected with ___, releasing ___ which induce ___.

Answer 16

identify and attach, viruses, chemicals, apoptosis

Question 17

What do natural killer cells do? (2)

Answer 17

identify and attach to virus infected cells.
release chemicals that induce apoptosis

Question 18

A wide range of ___ ___ cells constantly circulate, ___ the tissues.

Answer 18

white blood, monitoring

Question 19

If tissues become ___ or are ___, then cells release ___ that increase ___ flow, resulting in both ___ and __-___ white blood cells ___ at the site.

Answer 19

damaged, infected, cytokines, blood, specific and non-specific, accumulating

Question 20

What do cytokines do?

Answer 20

increase blood flow

(resulting in an accumulation of both specific and non-specific white blood cells at the site of infection)

Question 21

When are cytokines released?

Answer 21

when cells are damaged/infected

Question 22

Mammals contain different ___, each with a ___ on its surface, which can potentially recognise a ___ ___.

Answer 22

lymphocytes, receptor, parasite antigen

Question 23

The binding of an ___ to a lymphocyte’s receptor causes ___ of that lymphocyte, creating a ___ ___.

Answer 23

antigen, replication, clonal population

Question 24

How can lymphocytes fight pathogens? (2)

Answer 24

they can produce antibodies, or induce apoptosis in infected cells

Question 25

Antibodies possess regions of great ___ in their amino acid sequences.

Answer 25

variation

Question 26

The variable region of amino acids in an antibody’s amino acid sequence gives the antibody its ___ for binding ____.

Answer 26

specificity, antigens

Question 27

When an antigen binds to an antibody’s activet site, the antigen-antibody complex formed can result in…
1…..
2….

Answer 27

1. inactivation of the parasite, rendering it succeptible to an attack from a phagocyte.
2. stimulation of a response which results in cell lysis

Question 28

What is cell lysis?

Answer 28

the breakdown of a cell caused by damage to its outer membrane

Question 29

Initial antigen exposure produces ___ ___ cells, which are specific to that ___, and can produce a secondary response should…

Answer 29

memory lymphocyte, antigen, the same, antigen enter the body for a second time

Question 30

Should an antigen enter the body for a second time, ___ ___ cells will have been produced, which result in ___ antibody production, in terms of ___ of production, ___ in blood and ___.

Answer 30

memory lymphocytes, enhanced, speed, concentration, duration.

Question 31

What does a natural killer cell do?
What does an antigen-antibody complex do?
What do lymphocytes do?

Answer 31

1. identify and attach to virus infected cells and release chemicals that induce apoptosis.
2. Inactivation of the parasite or cell lysis
3. release chemicals which induce apoptosis or produce antibodies - after being cloned

Question 32

Which three things do memory lymphocytes enhance/improve during the secondary response to a pathogen?

Answer 32

increased concentration in blood of antibodies, increased duration, and increased speed of production