Bio 1Br June 2021

Question 1

Role of chlorophyll

Answer 1

• Absorb light
• for photosynthesis

Question 2

Substance digest fat

Answer 2

Lipase

Question 3

substance diffuse across synapse

Answer 3

Neurotransmitter

Question 4

Substances that prevent scurvy

Answer 4

Vitamin c

Question 5

What is organ

Answer 5

Different tissues carrying out a particular function

Question 6

The list gives the effects of adrenaline on different parts of the body.

• dilates the pupil in the eye
• increases heart rate
• narrows small arteries in the intestine
• converts glycogen into glucose in the liver.

Explain the advantages of these effects to a person in danger.

Answer 6

Dilates pupil:
- allow more light into retina
- increase awareness

Increase heart rate and
narrow small arteries in the intestine:
- more blood to lungs
- more oxygen to muscles
- more respiration

Converts glycogen into glucose in the liver:
- more glucose to muscles
- more respiration
- More energy

Question 7

5 Role of bile in digestion

Answer 7

• Increase surface area
• Neutralise acid
• optimal pH for enzymes
• emulsifies lipid
• Breaks down large droplet into small droplet

Question 8

How Villi adapt to their function

Answer 8

• Large surface area
• Microvilli
• One cell thick for short diffusion
• Capillaries to maintain concentration gradient
• Lacteal to absorb fats
• absorb digested food

Question 9

What happened to damaged villi

Answer 9

• Villi becomes shorter
• Surface area decrease
• less absorption of digested food
• less glucose, amino and minerals

Question 10

Why potted plants put in dark for 24 hours

(Test leaf for starch)

Answer 10

• Prevent photosynthesis
• Remove starch by respiration

Question 11

Describe how to test the leaves for starch safely.

Put in precautions too if it mentions about safety (notes)

Answer 11

• Heat leaf in boiling water
• heat in ethanol using water bath (remove chlorophyll)
• Wears safety glasses
• Add iodine solution
• Turn blue black is present

Question 12

What happens to leaf with strip of black paper on it

(Test leaf for starch)

Answer 12

• No starch present under paper
• Due to not having chlorophyll
• So it does not turn blue black when added iodine

Question 13

Why plants store carbohydrate such as starch rather than glucose

Answer 13

• Starch is insoluble
• Therefore it can’t diffuse out

Question 14

Haploid and diploid according to karyotype

Answer 14

Haploid is onefull set of chromosomes

Diploid is two full set of choromosomes

Question 15

Suggest how one might have extra chromosomes

Answer 15

• mutation
• failure of chromosomes to seperate during meiosis

Question 16

Why female over 35 are more likely to give birth to baby with genetic disorder

Answer 16

• Gametes are older
• mutations are more likely

Question 17

Transgenic definition

Answer 17

• Transfer of gene
• From a different species

Question 18

Effects of temperature on growth of snail

Answer 18

• enzymes gain more kinetic energy
• More frequent collisions
• Faster respirations

Question 19

Explain why the assimilation efficiency of a primary consumer is less than the
assimilation efficiency of a secondary consumer.

Assimilation efficiency is the percentage of food that is eaten and not egested as faeces.

Answer 19

• eat producers
• cannot digest parts

Question 20

Why mammal has lower food that is made into new biomass

Answer 20

• Maintain body temp
• Mammal respire more
• heat loss

Question 21

How style helps tissue to grow

Answer 21

• supplies glucose
• respiration
• make protein
• supply water
• cell elongation

Question 22

Why mouse uses more oxygen than human

Answer 22

• mouse is smaller
• larger surface area to volume ratio
• maintain body temp
• more respiration

Question 23

Differences between frog heart and human heart

Answer 23

• human heart has 4 chambers
• frog heart has 3 chambers

Question 24

Explain how the structure of the heart of a frog means that it is unable to
move for long periods of time.

Answer 24

no semi lunar valve:
- blood can flow back to ventricle
-less oxygenated blood to body
- less respiration

One ventricle:
- oxygenated blood and deoxygenated blood mix
- less efficient gas exchange

Question 25

Plasma transport named substances

Answer 25

• glucose : intestine to liver
• amino acids: Ileum to
  body/liver
• Fatty acids: Intestine to cells
• Hormones: endocrine glands to organs/tissues
• Urea: Liver to kidney
• CO2: Cells to lungs
• Antibodies: To infection
• Clotting proteins: to wound

Question 26

How phagocytes defend body from infection

Answer 26

• Ingest pathogen
• release digest enzymes

Question 27

Test plasma for protein

Answer 27

• Add biuret
• Turns blue black