AQA AS Biology Questions

During the Benedict's test for [blank_start]reducing[blank_end] sugars, copper(II) [blank_start]sulphate[blank_end] goes to copper(I) [blank_start]oxide[blank_end] and forms a [blank_start]red[blank_end] precipitate.

Maltose is formed from [blank_start]2[blank_end] [blank_start]alpha[blank_end] glucose

Sucrose is made from:

Glycogen is an [blank_start]energy[blank_end] source for [blank_start]animals[blank_end]. [blank_start]Starch[blank_end] is an energy source of plants. [blank_start]Celluose[blank_end] is a structural molecule for plants.

Starch has [blank_start]unbranched[blank_end] chains and has a [blank_start]helical[blank_end] structure which means it is compact. You test for starch with the [blank_start]iodine test[blank_end] which uses [blank_start]potassium iodide[blank_end] solution. A positive result is [blank_start]blue-black[blank_end].

Which is not a function of lipids:

Collagen is a globular protein.

Water molecules are polar.

Label this diagram of ATP

What type of enzyme inhibition is this?

What type of enzyme inhibition is this?

In DNA, the [blank_start]purine[blank_end] bases are adenine and guanine, and the [blank_start]pyrimidine[blank_end] bases are thymine and cytosine.

DNA replicates conservatively.

Label this diagram of a DNA nucleotide.

Which stage of mitosis is this?

Which stage of mitosis is this?

Label these organelles

Active transport is the movement of molecules or ions in or out of a cell from a region on [blank_start]lower[blank_end] concentration to a region of [blank_start]higher[blank_end] concentration using ATP and [blank_start]carrier[blank_end] proteins.

Which is not a physical barrier to pathogens

Phagocytes are specific.

The [blank_start]Cellular[blank_end] Immune Response: 1) Phagocyte becomes an [blank_start]antigen presenting cell[blank_end] after it has destroyed the pathogen 2) The antigen presenting cell releases cytokines and the helper [blank_start]T[blank_end] cell is activated 3) The helper T cell stimulates the production of [blank_start]cytotoxic[blank_end] T cells 4) Perforin is produced which cause [blank_start]lysis[blank_end] of the cells infected with pathogens 5) Exposure to the specific antigen causes [blank_start]memory[blank_end] cells to be produced

[blank_start]Humoral[blank_end] Immune Response: 1) The phagocyte becomes an [blank_start]antigen presenting cell[blank_end] after it destroys the pathogen 2) The antigen presenting cell stimulates the helper T cell by releasing [blank_start]cytokines[blank_end] 3) The helper T cell stimulates the differentiation of [blank_start]B lymphocytes[blank_end] 4) Some B lymphocytes become [blank_start]plasma[blank_end] cells which release large quantities of specific [blank_start]antibodies[blank_end] 5) Some B lymphoctes become [blank_start]memory[blank_end] cells

Select the statements that are true about Passive immunity

Select the statements that are true about Active immunity.

In fish, the blood and water flow in [blank_start]opposite[blank_end] directions. This is called [blank_start]countercurrent[blank_end] flow. This means a diffusion gradient is maintained all the way along the gill lamellae so almost all the oxygen diffuses out of the [blank_start]water[blank_end] into the [blank_start]blood[blank_end].

Label this diagram of the lungs

Which are not adaptations of the alveoli:

A high affinity for oxygen in haemoglobin means that the haemoglobin takes up O2 less easily at lower partial pressures of O2.

Label this diagram of the heart.

Arteries have a [blank_start]thick[blank_end] muscular layer which can be constricted and dilated to control the volume of blood passing through them. They have a thick [blank_start]elastic[blank_end] layer which helps to maintain blood pressure by stretching and [blank_start]recoiling[blank_end]. The overall thickness of the artery help to prevent [blank_start]bursting[blank_end]. There are no [blank_start]valves[blank_end].

Veins have a [blank_start]thin[blank_end] muscular layer which can [blank_start]constrict[blank_end] to control the flow of blood. They have a thin elastic layer. They have very thin walls since the pressure is [blank_start]lower[blank_end] and means they can be flattened easily to aid the flow of blood. There are valves throughout which ensure the blood doesn't flow [blank_start]backwards[blank_end].

Splicing removes the introns from pre-mRNA.

The region of tRNA that is complementary to a codon on mRNA is called an [blank_start]anti-codon[blank_end].

During meiosis, the chromosome number [blank_start]halves[blank_end] and [blank_start]4[blank_end] haploid cells are are genetically [blank_start]different[blank_end] are produced.

Crossing over occurs during meiosis [blank_start]1[blank_end]

Mutagenic agents increase the [blank_start]rate[blank_end] of mutations.

What is the amino acid sequence for this sequence of mRNA UUC AGC GCG UAA

A genetic bottleneck will [blank_start]reduce[blank_end] genetic diversity. It is an event which causes a big [blank_start]reduction[blank_end] in the population so will reduce the number of [blank_start]alleles[blank_end]. The survivors will reprodue and the larger population is created from [blank_start]a few[blank_end] indiviuals.

Directional selection favours individuals with characteristics at the [blank_start]extremes[blank_end] of the population whereas stabilising selection favours individuals in the [blank_start]middle[blank_end] of the range when the environment [blank_start]isn't[blank_end] changing much.

Complete the table for the species: Ceyx azureus