Starter questions

Question 1

Describe how macrophages process antigens for presentation on their cell surface membrane

Answer 1

Antigen fragments combined with MHC (special glycoproteins in cytoplasm)

Question 2

What name is given to small protein molecules that act as cell-signalling compounds?

Answer 2

Cytokines

Question 3

State three passive physical defences that prevent plants being infected by a pathogen

Answer 3

Bark, waxy cuticle, thorns, spines, lignified cell walls, cellulose.

Question 4

State three factors that would affect the speed of disease transmission in plants

Answer 4

Overcrowding, poor mineral nutrition, damp warm humid conditions, climate change.

Question 5

Describe the difference between herd vaccination and ring vaccination

Answer 5

Herd vaccination is where everyone (or almost everyone) is vaccinated. Ring vaccination is vaccinating people around the site of the outbreak, so that the pathogen will not be transmitted across that ring to the whole population.

Question 6

Explain why passive immunity only provides short-term immunity

Answer 6

Passive immunity is provided by an external supply of antibodies - these are proteins and will not last long in the body. They may even act as antigens and be attacked by antibodies from our immune system

Question 7

Antibodies are made by plasma cells. Explain how plasma cells are speciaised for their role.

Answer 7

Plasma cells have a lot of ribosomes, rough endoplasmic reticulum, golgi apparatus and mitochondria. Ribosomes for proteinsynthesis, golgi for vesicles.

Question 8

Give an example of artificial active immunity

Answer 8

Immunity provided by antibodies made in response to vaccination (dead/inactive pathogens injected).

Question 9

Describe how B lymphocytes are activated and the role of activated B lymphocytes

Answer 9

The cell binds specifically to B lymphocyte, B lymphocyte differentiates into a plasma cell. Plasma cells release antibodies specific to the particular antigen.

Question 10

Describe how antitoxins function.

Answer 10

Neutralise toxin molecules released by a pathogen through direct binding.

Question 11

Where is bile stored?

Answer 11

Gall bladder

Question 12

What is negative feedback?

Answer 12

A response that is opposite to the stimulus, returning conditions back to the optimum

Question 13

What are 3 advantages of being ectothermic that are disadvantages to being endothermic

Answer 13

Ectotherms: use less energy from food for respiration, use more energy from food for growth, survive long periods without food

Question 14

Name 4 physiological responses in an endotherm that lead to a decrease in temperature

Answer 14

Piloerection, vasoconstriction, increased liver metabolism, shivering

Question 15

What is vasoconstriction?

Answer 15

Contraction of smooth muscle to narrow arterioles which restricts blood to the skin surface

Question 16

What 6 substances are reabsorbed in the proximal convoluted tubule?

Answer 16

Glucose, amino acids, water, mineral ions, vitamins, hormones

Question 17

What methods are used to test for the presence of anabolic steroids in urine?

Answer 17

Mass spectometry & gas chromotography

Question 18

What is the importance of selective reabsorption?

Answer 18

Get useful substances back into the body

Question 19

Where is ADH produced?

Answer 19

Hypothalamus

Question 20

What are the resident macrophages called in the liver?

Answer 20

Kupffer cells

Question 21

The bonds in polysaccharides are called…

Answer 21

Glycosidic bonds

Question 22

A polysaccharide is formed from…

Answer 22

Monosaccharides

Question 23

Starch is formed from…

Answer 23

Long chains of alpha glucose

Question 24

Glycogen is used for…

Answer 24

Energy storage molecules in animals

Question 25

Cellulose is made from...

Answer 25

Condensation reactions of beta glucose molecules

Question 26

Properties of polysaccharides are...

Answer 26

Insoluble in water, long chain molecules, not sweet tasting

Question 27

Starch is stored as...

Answer 27

Grains in chloroplasts

Question 28

Glycogen is found in...

Answer 28

Liver and muscle cells

Question 29

What is the main difference between active transport and facilitated diffusion?

Answer 29

Active transport requires ATP, whereas facilitated diffusion does not because it is passive.

Question 30

What is the water potential of water?

Answer 30

0 kPa (kilopascals)

Question 31

What is a glycolipid?

Answer 31

A lipid with a carbohydrate molecule attached

Question 32

Explain why alcohol is used in antiseptic wipes

Answer 32

Alcohol disrupts and dissolves the bacteria phospholipid bilayer due to the non-polar nature, killing the organelles in the cell

Question 33

State four functions of membranes within cells

Answer 33

Controls what enters and leaves the partially permeable plasma membrane. Site of chemical reactions. Compartmentalisation. Forms vesicles. Acts as a barrier between membrane contents and rest of organelle.

Question 34

Give an example of a conjugated protein

Answer 34

Haemoglobin, catalase

Question 35

Explain how a positive result is formed in Benedict's test

Answer 35

Reducing sugar reacts with blue Cu2+ to make brick red Cu+ precipitate

Question 36

Based on the arrangement of cellulose molecules, explain why cell walls provide strength and support to plant cells

Answer 36

Cellulose molecules form hydrogen bonds with each other to make microfibrils. Microfibrils join together to form macrofibrils which join further to form fibres. These fibres are insoluble and tough.

Question 37

State the bonds involved in the tertiary structure of a protein

Answer 37

Ionic Disulphide bridges between cysteine (covalent) Hydrogen bonds Hydrophobic interactions

Question 38

Describe the structure of amylopectin, including the bonds involved and the shape

Answer 38

Amylopectin is a polysaccharide with a branched structure. Includes 1-4 and 1-6 glycosidic bonds.