What is SNAB biology?

Introduction. Salters-Nuffield Advanced Biology (SNAB) is an advanced level Biology course. The course uses real-life contexts as a starting point to introduce relevant knowledge and understanding of biological principles. There is a focus on active learning using the multi media resources that accompany the course.

How many topics in Edexcel a level Biology?

eight topics

The specification is divided into eight topics.

Is Salters Nuffield Biology A or B?

A levels Biology (Salters-Nuffield)

What is the Hill reaction a level biology?

The Hill reaction involves isolating chloroplasts from living cells and suspending them in a coloured electron acceptor. In this case, the electron acceptor is the blue dye DCPIP.

How long is Edexcel biology A level?

Studying this specification
You’ll cover biological laws, theories, models and their practical applications as you study our Edexcel International AS/Advanced Level in Biology. Studied over one or two years, the course will help to develop: your interest in, and enthusiasm for, biology.

What is a level Biology B?

Our A Level in Biology B (Advancing Biology) qualification uses a context-based approach to enable students to develop their conceptual knowledge of essential biological topics in a variety of interesting and relevant settings.

What is the purpose of Hill reaction?

The Hill reaction is the light-driven transfer of electrons from water to Hill reagents (non-physiological oxidants) in a direction against the chemical potential gradient as part of photosynthesis.

What is Hill reaction and its significance?

The Hill reaction is the portion of the light reactions in which electrons from water are transferred to an electron acceptor, reducing the acceptor. This reaction was first observed by Robert Hill in 1937 and it was he who demonstrated that isolated chloroplasts can produce O₂ in the absence of CO2.

What topics are in Biology Paper 1 a level Edexcel?

The following outlines the structure of the Edexcel A level Biology exams. This paper covers:Topic 1: Lifestyle, Health and Risk, Topic 2: Genes and Health Topic 3: Voice of the Genome, Topic 4: Biodiversity and Natural Resources Topic 5: On the Wild Side Topic 6: Immunity, Infection and Forensics. 100 marks.

What topics are in biology paper 2 Edexcel A Level?

A Level Paper 2

  • Topic 1: Biological Molecules.
  • Topic 2: Cells, Viruses and Reproduction.
  • Topic 3: Classification and Biodiversity.
  • Topic 4: Exchange and Transport.
  • Topic 8: Origins of Genetic Variation.
  • Topic 9: Control Systems.
  • Topic 10: Ecosystems.
  • Practical Skills.

Is biology the hardest a level?

In order of easiest to most difficult, our list of the top 15 hardest A-Levels are: Art, Design & Technology (Product Design), Business Studies, Politics, Economics, History, English Literature, Psychology, Modern Languages, Mathematics, Computer Science, Biology, Chemistry, Further Mathematics, and Physics.

Is A2 Biology harder than as?

A2 Levels are generally harder than AS Levels. They build on the knowledge you learn taking your AS papers. Many A2 Level papers also test on the content covered in the AS papers. For example, business studies A2 exams require you to recall knowledge from AS business studies.

What is the other name of Hill reaction?

Hill reagent
These are known as Hill reagents. These dyes permitted the finding of electron transport chains during photosynthesis. Dichlorophenolindophenol (DCPIP), an example of these dyes, is widely used by experimenters.

What is Hill reaction also known as?

b) Hill Reaction: Photochemical phase in photosynthesis is called Hill reaction or light reaction. It occurs inside the granal thylakoids of chloroplasts. It is dependent upon light.

What is called Hill’s reaction?

Definition of Hill reaction
: the light-dependent transfer of electrons by chloroplasts in photosynthesis that results in the cleavage of water molecules and liberation of oxygen.

How many papers are there in AS level biology?

The specification consists of three externally examined papers and the Science Practical Endorsement. The paper will include multi-choice, short open, open-response, calculations and extended writing questions.

How many A level biology exams are there?

To achieve your A Level Biology qualification, you must complete the exams. There are three written exams and twelve practical assessments for this course which will cover the topics studied on this course.

What are the 4 hardest A levels?

What are the hardest A-Levels?

  • Psychology.
  • English Literature.
  • History.
  • Economics.
  • Politics.
  • Business Studies.
  • Design & Technology (Product Design)
  • Art. Surprisingly, Art A-Level is often ranked among some of the most difficult A-Level subjects to take, despite the common assumption that it is a ‘soft’ subject.

What is the toughest subject in the world?

The hardest degree subjects are Chemistry, Medicine, Architecture, Physics, Biomedical Science, Law, Neuroscience, Fine Arts, Electrical Engineering, Chemical Engineering, Economics, Education, Computer Science and Philosophy. Let’s dive right in, and look at why these subjects are the hardest degree subjects.

CAN I GET A in A2 if I get B in as?

Generally, yes. To get an A in modular a levels, you need to get 80% overall, with your AS grades counting for half of the total. The worst B you could have would be an AS total of 70%.

What is the significance of Hill reaction?

Hill Reaction of the Photosynthesis was found by Robert Hill (1939). He found that isolated chloroplasts from plants can discharge oxygen (O2 ) when they are illuminated by sunlight (or by a light source same to sunlight) in the prescence of suitable electron acceptor such as Ferricyanide.

What is Hill’s reaction why it so called?

What are the products of Hill reaction?

Hill’s reaction or light reaction takes place in thylakoids and the end products of this reaction are ATP and NADPH2.

Which is known as Hill reagent?

Discovered in 1937 by Robin Hill, Hill reagents allowed the discovery of electron transport chains during photosynthesis. These are dyes that act as artificial electron acceptors, changing color when they are reduced. An example of a Hill reagent is 2,6-dichlorophelindophenol (DCPIP).

What is the hardest a level?

Why are you using several roots?

Why are you using several roots? The roots become very delicate during the preparation stage and may decompose. Using several roots increases the likelihood that one root tip will survive to give a good root tip squash.

two years
Studying this specification

How do you cook root tip squash?

So you remove the tips of some garlic roots. And you carry out a staining procedure in order to be able to see those chromosomes. The cells are sort of frozen.

How many topics are in Edexcel A Level biology?

Why do we add HCL to root tip?

The root tip is heated with acid to break up the tissues into individual cells. The cellulose walls of plant cells are held together by pectins such as calcium pectate. Treatment with hydrochloric acid breaks this down.

Why is root tip used to observe mitosis?

Why is onion root tip used to demonstrate mitosis in this experiment? It is because of the meristematic cells that are situated in the tip of the roots that render the most desirable and suitable raw material to study the different stages of mitosis.

Students are expected to carry out 16 core practical experiments.

What is squash in microbiology?

research use in cytogenetics
In genetics: Cytogenetics. …the development of the so-called squash technique, in which entire cells are pressed flat on a piece of glass and observed through a microscope; the human chromosomes were numbered using this technique.

Why do we add HCl to root tip?

Why Acetocarmine is used in nuclear staining?

Acetocarmine is a DNA specific stain like feulgen stain, so the super coiled chromosomes during different stages of mitosis present in the onion root tip cells can be visualized perfectly by treating with this stain.

Why HCL is used in mitosis?

4 – the purpose of the hydrochloric acid is to destroy the substances that unite the cells (usually pectin), but it does not destroy the cell walls. The hydrochloric acid also has the ability to kill the cells and halt the process of mitosis. …

Why do scientists use root tips to study the cell cycle?

Answer and Explanation: Onion root tips are commonly used to study mitosis. They are sites of rapid growth, so the cells are dividing rapidly. When an onion root tip is evaluated under a microscope, you can generally see all of the phases of mitosis within one field.

Why Acetocarmine stain is used in mitosis?

What is the hardest A-level?

Is biology a hard A-level?

For those of you wanting the short answer: A-Level Biology is quite a hard A-Level, even for the most skilled science students. It’s a completely different ball game to GCSE, it goes much more into depth and there’s a lot more content you need to know.

What is squash preparation in biology?

squash prep
The smearing or compressing of a thin tissue specimen between two slides before microscopic analysis. The specimen is placed flat on the first slide. The second slide is held at a right angle to the first and then dragged along the specimen, distributing it lengthwise along the first slide.

What is the meaning of squash method?

In genetics: Cytogenetics. …the development of the so-called squash technique, in which entire cells are pressed flat on a piece of glass and observed through a microscope; the human chromosomes were numbered using this technique.

How many papers are in a level biology?

The specification consists of three externally examined papers and the Science Practical Endorsement.

Why acetocarmine is used for staining and not Safranin?

What colour does acetocarmine stain?

The acetocarmine produces its usual staining effects, i.e., nuclei dark red and some components of the cytoplasm of certain cells a less intense red. The Sudan black B colors lipid structures an intense blue.

What is the purpose of using HCl in this experiment?

The purpose of adding hydrochloric acid in the experiment is to remove any carbonate ions that might be present in the unknown, so that barium carbonate will not precipitate along with barium sulfate.

Why are root tips used in biology labs to observe mitosis?