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AQA A Level Biology > Random Biology 🧬🧫 > Flashcards

Random Biology 🧬🧫 Flashcards

(40 cards)

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1
Q

Suggest why log scales are used in biology (1 mark)

A

Large range of data

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2
Q

Explain how the second messenger model of glucagon works (5 marks)

A
  • Glucagon binds to receptors on liver cell membrane
  • This causes a change in the shape of the enzyme adenylate cyclase, activating it
  • This enzyme converts ATP into cAMP
  • cAMP activates kinase
  • Which catalyses the hydrolysis of glycogen into glucose
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3
Q

Explain how the second messenger model of adrenaline works (5 marks)

A
  • Adrenaline binds to receptors on liver cell membrane
  • This causes a protein (G protein) to be activated
  • This enzyme converts ATP into cAMP
  • cAMP activates kinase
  • Which catalyses the hydrolysis of glycogen into glucose
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4
Q

State the first and second messengers in the second messenger model of glucagon (2 marks)

A
  • First: glucagon

- Second: cAMP

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5
Q

Describe how a low blood glucose concentration is detected (3 marks)

A
  • Detected by alpha cells
  • In the Islets of Langerhans
  • In the pancreas
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6
Q

State where glucagon and insulin are secreted from (1 mark)

A

Pancreas

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7
Q

State where adrenaline is secreted from (1 mark)

A

Adrenal glands

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8
Q

Describe how a high blood glucose concentration is detected (3 marks)

A
  • Detected by beta cells
  • In the Islets of Langerhans
  • In the pancreas
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9
Q

Suggest how you would ensure that data is representative (2 marks)

A
  • Random samples

- Large sample

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10
Q

DNA –> mRNA (1 mark)

A

Transcription

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11
Q

mRNA –> tRNA (1 mark)

A

Translation

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12
Q

Explain what a P value of less that 0.02 suggests (2 marks)

A
  • Probability that difference is due to chance is
    less than 0.05
  • Reject null hypothesis
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13
Q

Polymer in cell walls of plants (1 mark)

A

Cellulose

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14
Q

Polymer in cell walls of prokaryotes (1 mark)

A

Murein

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15
Q

Polymer in cell walls of algae (1 mark)

A

Cellulose

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16
Q

Polymer in cell walls of fungi (1 mark)

A

Chitin

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17
Q

Things to look out for when evaluating conclusions (6 marks)

Study These Flashcards
A
  • Stats test
  • Sample size
  • Humans or animals?
  • Other factors involved
  • Correlation does not mean causation
  • STDs + significance
18
Q

State the location of chemoreceptors and baroreceptors (1 mark)

19
Q

Name three monosaccharides (3 marks)

Study These Flashcards
A
  • Glucose
  • Galactose
  • Fructose
20
Q

State some properties of glycogen which make it suitable for its functions (3 marks)

Study These Flashcards
A
  • Branched (for quick hydrolysis of enzymes)
  • Insoluble (so not affected by water potential)
  • Compact (good storage)
21
Q

State the number of water molecules produced during the formation of triglycerides (1 mark)

22
Q

State and explain the properties of triglycerides, relating them to their function (8 marks)

Study These Flashcards
A
  • Energy storage
  • -> Large ratio of energy storing C-H bonds compared to the number of C atoms
  • Metabolic water source
  • -> High ratio of H to O atoms so if oxidised, they release water
  • Do not affect water potentials and osmosis
  • -> Large and hydrophobic, so insoluble in water
  • Good storage molecule
  • -> Low mass so doesn’t make animal more heavy
23
Q

Explain how enzymes lower the activation energy of a reaction (3 marks)

Study These Flashcards
A
  • Active site is induced / slightly changes shape to mould around the substrate
  • When the E-S complex forms, the enzyme moulding puts a strain on the substrate’s bonds, weakening them
  • This lowers the activation energy
24
Q

State the molecules which form ribosomes (2 marks)

Study These Flashcards
A
  • RNA

- Proteins

25
State the function of RNA (1 mark)
Transfers genetic information from DNA to ribosomes
26
State the sugar in a nucleotide (1 mark)
Deoxyribose
27
Where are phosphodiester bonds formed (1 mark)
Between 2 nucleotides
28
``` State the roles of each of the following ions in the body: - Hydrogen ions - Iron ions - Sodium ions - Phosphate ions (8 marks) ```
Hydrogen ions - Lowers pH of solutions - Could impact enzyme / haemoglobin function - Involved in chemiosmosis Iron ions - Component of haemoglobin in the transport of oxygen Sodium ions - Involved in the co-transport of glucose and amino acids during absorption - Plays a role in generating action potentials Phosphate ions - Component of DNA (phosphodiester bonds) - Component of ATP
29
Function of Golgi vesicles (1 mark)
- Store proteins and lipids made by Golgi Apparatus and transport them around the cell
30
Function of Golgi Apparatus (1 mark)
Processes + packages proteins and lipids made in the rough ER
31
Function of vacuole (1 mark)
Absorbs water by osmosis and swells, keeping the cell rigid
32
When are chromosomes visible in a cell (1 mark)
When they are condensed
33
Length of stage micrometer (1 mark)
100 micrometers
34
Structure of endoplasmic reticulum (2 marks)
- Both rough and smooth have folded membranes called cisternae - Rough has ribosomes on the surface
35
Structure of golgi apparatus (2 marks)
- Folded membranes make cisternae | - Vesicles on the surface of cisternae
36
Function of golgi apparatus + vesicles (3 marks)
- Adds carbs to proteins to form glycoproteins - Produces secretory enzymes - Transports modifies + stores lipids
37
Function of RER + SER (2 marks)
RER - Site of protein synthesis | SER - Synthesises stores lipids + carbohydrates
38
Function of lysosomes (3 marks)
- Involved in phagocytosis - Break down dead cells - Digest worn out organelles for reuse of materials
39
Describe the structure of mitochondria (4 marks)
- Double membrane - Inner membrane called the cristae - Fluid centre called he mitochondrial matrix - Loop of mitochondrial DNA
40
Explain why the determination of dry mass is an appropriate method to use to compare growth of plants (2 marks)
- Determines increase in organic material | - Water content varies

AQA A Level Biology (14 decks)

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