Aqa a level biology test - Study guides, Class notes & Summaries

AQA A-level BIOLOGY 7402/3 Paper 3 Mark scheme June 2023 (VERIFIED) (There are) stretch-mediated sodium ion channels (in the membrane); 2. (Increased pressure) deforms/changes (sensory neurone/axon) membrane/lamella(e) OR (Increased pressure) deforms/changes sodium ion channels; 3. Sodium ion channels open; 4. Sodium ions diffuse in; 5. Depolarisation (leading to generator potential); 3 max (3 x AO1) 1. 2. 3. or 4. Accept Na+ Max 2 if only reference to sodium and not sodium ions...

AQA A level Biology Exam || Revision Questions & Answers (Graded A+) AQA A level Biology Exam || Revision Questions & Answers (Graded A+) Describe how you would use a biochemical test to show that a solution contained a non-reducing sugar, such as sucrose. [3] - ANSWER - ,first reducing sugars test; boil with dilute HCl acid then Neutralise with NaHCǑ, add benedict and heat to 95 degrees C brick red ppt forms if reducing sugar is present Describe a chemical test you could carry out to sh...

AQA A LEVEL BIOLOGY Paper 1 2024 What is the function of the cell membrane? - ANS To control what enters and leaves the cell, acts as a barrier between the cell and its environment. What structural feature of the cell membrane allows substances to enter/leave? - ANS Partially permeable What is the fluid mosaic model? - ANS States that a membrane is a fluid structure (because phospholipids are constantly moving) with a "mosaic" of various proteins embedded in it Describe t...

AQA A-level Biology paper 1 Questions and Answers 100% Solved large molecules often contain carbon. why? they can readily form bonds with other carbon atoms. this forms a 'backbone'. other atoms can then attach. describe benedicts test for reducing sugars add equal volumes of the sugar sample and benedicts reagent. heat the mixture in a water bath for 5 minutes. brick red precipitate will form. what is a reducing sugar? a sugar that can reduce (give electrons to) another chemical. des...

AQA A-level Biology paper 1 Test Questions with Answers!!! Benedict's test - ️️ -Which food test is heated in a water bath? Sucrose - ️️ -Which disaccharide is not a reducing sugar? Test for non-reducing sugars - ️️ -Add acid. Neutralise. Add Benedicts. Heat. Hydrolysis - ️️ -Reaction performed by dilute HCl in the non reducing sugar test. Glucose + fructose - ️️ -During the non-reducing sugar test what is sucrose hydrolysed into? Alpha - ️️ -Which type of glucos...

AQA A level BIOLOGY 7402/3 Paper 3 Mark scheme June 2023. (There are) stretch-mediated sodium ion channels (in the membrane); 2. (Increased pressure) deforms/changes (sensory neurone/axon) membrane/lamella(e) OR (Increased pressure) deforms/changes sodium ion channels; 3. Sodium ion channels open; 4. Sodium ions diffuse in; 5. Depolarisation (leading to generator potential); 3 max (3 x AO1) 1. 2. 3. or 4. Accept Na+ Max 2 if only reference to sodium and not sodium ions 4. Accep...

AQA A-level BIOLOGY 7402/3 Paper 3 Mark scheme June 2023 | VERIFIED. (There are) stretch-mediated sodium ion channels (in the membrane); 2. (Increased pressure) deforms/changes (sensory neurone/axon) membrane/lamella(e) OR (Increased pressure) deforms/changes sodium ion channels; 3. Sodium ion channels open; 4. Sodium ions diffuse in; 5. Depolarisation (leading to generator potential); 3 max (3 x AO1) 1. 2. 3. or 4. Accept Na+ Max 2 if only reference to sodium and not sodium ion...

BIOLOGY AQA AS LEVEL 74011 PAPER 1[REAL 100%] • The human cell then makes a complementary strand to the HIV DNA. The complementary strand is made in the same way as a new complementary strand is made during semi-conservative replication of human DNA. Describe how the complementary strand of HIV DNA is made. - ANS---- there are complementary nucleotides/bases pair - DNA polymerase used - Nucleotides join together (to form new strand)/phosphodiester bonds form; Describe the difference be...

AQA A-level BIOLOGY 7402/3 Paper 3 Mark scheme June 2023. (There are) stretch-mediated sodium ion channels (in the membrane); 2. (Increased pressure) deforms/changes (sensory neurone/axon) membrane/lamella(e) OR (Increased pressure) deforms/changes sodium ion channels; 3. Sodium ion channels open; 4. Sodium ions diffuse in; 5. Depolarisation (leading to generator potential); 3 max (3 x AO1) 1. 2. 3. or 4. Accept Na+ Max 2 if only reference to sodium and not sodium ions 4. Accep...