quiz 2

Question 1

what layers are visible upon centrifugation of blood?

Answer 1

plasma, leukocytes and erythrocytes

Question 2

Blood vessel A is three times the diameter of blood vessel B. Compare their resistance and flow

Answer 2

Resistance in vessel A is 1/81 that of vessel B as resistance = 1/(r^4). Flow in vessel A is 81 times that of vessel B as flow = r^4

Question 3

What is the function of Type I cells in the lungs?

Answer 3

they’re the cells in alveoli across which gas exchange occurs

Question 4

what are the three germ layers?

Answer 4

ectoderm, mesoderm, endoderm

Question 5

what are the three structural types of capillaries?

Answer 5

continuous, fenestrated and sinusoids

Question 6

what are capacitance vessels?

Answer 6

blood reservoirs that contain 65% of the blood supply

Question 7

Describe endospore structure

Answer 7

Endospores are structurally complex. They’re enriched with calcium ions. They contain dipicolinic acid and their core contains SASPs (small acid soluble proteins)

Question 8

What is serum therapy?

Answer 8

Passive antibody therapy first used in the 1890s. Antibodies are specific to the pathogen and are taken from an immunised individual. It can show lot to lot variation

Question 9

what type of blood cell is the first line of defence in the body’s immune system?

Answer 9

granulocytes

Question 10

describe some of the functions of the gut microbiota

Answer 10

• de-polymerisation of complex carbohydrates
• produce glycosidehydrolases and polysaccharide lysases
• ferment saccharides as the main source of energy for intestinal epithelial cells
• synthesise essential amino acids and vitamins

Question 11

why is folic acid recommended to pregnant people?

Answer 11

advised to be taken when trying to get pregnant and up to 12 weeks pregnant to significantly reduce risk of neural tube defects eg spina bifida

Question 12

what is the heart’s natural pacemaker in a healthy individual?

Answer 12

the sinoatrial node. Found in the wall of the right atrium and produces an electrical impulse that travel through the heart and cause contraction, setting the rhythm of the heart

Question 13

what is the main factor affecting peripheral resistance in blood vessels?

Answer 13

the degree of constriction of the arterioles (arteriolar tone)

Question 14

what is emphysema?

Answer 14

long term progressive disease that causes alveoli sac to break and burst. It also damages the bronchioles leading to difficulty in emptying gases from the alveoli. Therefore, gas exchange sites will be lesser than the normal healthy person. Smoking is known to increase the risk of developing this condition.

Question 15

What affects blood pressure?

Answer 15

blood volume, peripheral resistance and cardiac output

Question 16

what is the typical blood pressure in a normal healthy individual?

Answer 16

120/70 mmHg

Question 17

outline the order of human evolution

Answer 17

Primates -> Hominidae -> Homininae -> Hominini -> Humans

Question 18

According to molecular data, when did humans and chimps share a common ancestor?

Answer 18

5 to 8 million years ago

Question 19

what does an embryoblast go on to form?

Answer 19

an embryo

Question 20

What is the function of the SRY gene?

Answer 20

it codes for a transcription factor which regulates the gene producing anti-Mullerian hormone

Question 21

what is a primary endocrine organ?

Answer 21

organ with main function being to secrete hormones

Question 22

what is a secondary endocrine organ?

Answer 22

an organ which secretes hormones but that’s not its main function

Question 23

outline the order of how life on Earth is thought to have begun

Answer 23

simple molecules (eg elements) -> complex molecules (eg lipids/proteins) -> organisation into cells -> replication -> complex biological pathways

Question 24

Which scientist proposed the ‘Primordial Soup’ theory?

Answer 24

Alexander Oparin

Question 25

What is asthma?

Answer 25

Chronic inflammatory disease of the airways where the smooth muscle around the bronchioles contracts more than normal. Increased mucus production limits airflow in and out of the lungs.

Question 26

how many children and adults are affected by asthma in the UK?

Answer 26

approx 1.1 million children and 4.3 million adults

Question 27

how is asthma treated?

Answer 27

using beta-adrenoreceptor agonists eg Salbutamol

Question 28

how many people in the UK are affected by emphysema?

Answer 28

1.2 million

Question 29

outline the visual pathway

Answer 29

retina -> optic nerve -> optic chiasm -> lateral geniculate body -> primary visual cortex

Question 30

what will excess secretion of thyroid hormones lead to?

Answer 30

weight loss as thyroid hormones play a role in determining the basal metabolic rate

Question 31

what type of relationship is seen between fungi and algae in lichen?

Answer 31

Mutualistic as the fungi provide protection and structure and the algae produce organic matter

Question 32

what is a commensal relationship?

Answer 32

a relationship where one organism benefits and the other is neither benefited or harmed

Question 33

function of ADH

Answer 33

causes urine to become more concentrated by increasing water reabsorption in the DCT by inserting aquaporins

Question 34

why does the thyroid gland require iodine?

Answer 34

to synthesise thyroid hormones T4 and T3. Iodine deficiency can lead to cretinism