Explanation​:
Louis Pasteur's experiments where he boiled nutrient broth in swan-necked flasks disproved spontaneous generation. Choice B is correct.

Miller and Urey's (Choice A) experiments proved that organic compounds could be produced in Earth’s early atmosphere. Rosalind Franklin’s (Choice C) work was instrumental in the discovery of the structure of DNA. Meselson and Stahl (Choice D) proved that DNA replication is semi-conservative.

Explanation​:
Choice A is correct because the hierarchy of taxa is a domain, kingdom, phylum, class, order, family, genus, so class $\to$ order $\to$ family is in the correct order. Choice B is incorrect because the class is above order. Choice C is incorrect because the family is above genus. Choice D is incorrect because the phylum is above order.

Explanation​:
Unlike eukaryotes, prokaryotes lack a nucleus and membrane-bound organelles. However, like eukaryotes, prokaryotes contain ribosomes, a non-membrane-bound organelle required for protein synthesis. So, ribosomes are found in both prokaryotes and eukaryotes.

Lysosomes (Choice A) and the Golgi apparatus (Choice C) are only found in eukaryotes. The nucleoid (Choice D) is only found in prokaryotes.

Explanation​:
The nucleotide strand CCUAGAGCUUACCG contains the bases cytosine (C), uracil (U), adenine (A), and guanine (G). While C, A, and G are found in both DNA and RNA, the base uracil is only found in RNA. So, the strand is an RNA strand.

RNA contains the pentose sugar ribose. Therefore, ribose is found in the nucleotides in the strand.

Choices A and C are incorrect because deoxyribose is only found in DNA, not RNA. The nucleotide strand cannot be DNA because it contains uracil in place of thymine (T).

Choice D is incorrect because the strand is RNA which contains ribose.

Explanation​:
Eukaryotic cells contain mitochondria but prokaryotic cells do not. Choice A is correct.

Choices B and D are incorrect as the cell is not prokaryotic; it has a nucleus. Choice C is incorrect because the cell has a nucleus.

Explanation:
Statement I is true because all cells have cytoplasm enclosed by the plasma membrane.

Statement II is also true because the invention of the microscope made viewing structures within the cell easier.

Statement III is false because all cells have genetic material. Eukaryotic cells have their genetic material inside of the nucleus, while prokaryotes have their genetic material in the nucleoid region.

Explanation​:
Nucleotides are linked together by condensation reactions to form molecules of DNA (Choice B). The formation of DNA requires the removal of water for the joining of smaller molecules to form a larger molecule.

The joining of nucleotides together can also be classified as an anabolic reaction but not as a catabolic reaction (Choice C). Catabolism is the breaking down of a large molecule into a smaller molecule. An example of catabolism is hydrolysis which is a reaction that breaks down a large molecule into a smaller molecule by adding water (Choice A).

Translation is a process which follows the transcription of DNA (Choice D). It is where mRNA is used as a template by ribosomes to synthesize polypeptides.

Explanation​:
Species that share a recent common ancestor, such as humans and chimpanzees, are more likely to have similar base sequences. Over time, as species diverge and evolve, mutations accumulate in their base sequences. The longer two species have been separated from their common ancestor, the more mutations will have accumulated in their genomes. Therefore, species that are closely related have fewer accumulated mutations and more similar base sequences (Choice B).

Choice A is incorrect because genome size is not necessarily proportional to the size of the species. The genome size can vary significantly even among organisms of similar size, and organisms with similar-sized genomes, such as the horse and mouse vary greatly in size. Choice C is incorrect because it is possible to have a larger genome size with a comparable, or even smaller, number of genes, depending on the amount of non-coding DNA and repetitive sequences present in the genome. Humans have a larger genome but a similar number of genes to the chimpanzee, mouse and horse. Choice D is incorrect because although the nucleotide base sequence in the table for humans and chimpanzees is the same it does not mean that their whole genome is the same.

Explanation:
Adhesive properties (Choice B) refer to water’s ability to stick to charged surfaces or polar molecules. This, together with cohesion, allows water to move against gravity up the stem through capillary action.

Water's melting point (Choice A) is the temperature at which it changes its state from solid to liquid.

The specific heat capacity (Choice C) of water pertains to the amount of heat energy needed to raise its temperature by 1 °C.

The buoyant force of water (Choice D) is the upward force on an object submerged or partially immersed in water, equal to the weight of the displaced water.

Explanation:
Bound ribosomes synthesise proteins for secretion outside of the cell, membrane-associated proteins or proteins used in lysosomes (Choice D).

Choice A is incorrect, as free ribosomes synthesise proteins for use primarily within the cytoplasm.
Choice B is incorrect as bound ribosomes do not transport mRNA from the nucleus to the cytoplasm.
Choice C is incorrect as ribosomes do not destroy proteins.

Explanation​:
Cholesterol (Choice C) is a non-polar hydrophobic molecule. Therefore, it is insoluble in water.
Glucose (Choice A), amino acids (Choice B), and sodium chloride (Choice D) are soluble in water and are hydrophilic.

Explanation:
The resolution is the ability to distinguish between two objects. Choice B is correct.

Choices A and D are incorrect because a photograph taken using an electron microscope would allow the ultrastructure of the cells (fine detail of cells, such as organelles) to be observed. Choice C is incorrect because these photographs are magnified at the same power.

Explanation:
DNA molecules consist of four nitrogenous bases: adenine (A), cytosine (C), guanine (G) and thymine (T). In DNA molecules, adenine always pairs with thymine and cytosine always pairs with guanine. This is known as complementary base pairing.

Sequences I and III both follow base-pairing rules correctly. Statement II is incorrect because it shows T paired with G and A paired with C.

Explanation​:
The number of organisms found via the fossil record for any era is much lower compared to the number of organisms found on Earth now and those that continue to be found, so Choice B is correct. Choice A is incorrect as changing levels of atmospheric carbon dioxide provide evidence for humans' impact on carbon dioxide levels. Choices C and D are incorrect as evidence suggests that the rate of evolution and speciation are increasing, which provides evidence for increasing biodiversity.

Explanation:
Choice A is correct because Chargaff used paper chromatography to show that the proportions of adenine (A) and thymine (T) are the same, as are the proportions of guanine (G) and cytosine (C). There are not equal proportions of A, T, G and C.

Franklin (Choice B) and Watson (Choice D) are credited for their contributions to the overall structure of DNA structure. Hershey (Choice C), along with Chase, is famous for his research which provided evidence for the idea that DNA, rather than protein, carries the genetic code.

Explanation​:
All three statements are correct. The first part of the binomial name is the genus, the second part is the species which is unique to platypus species. The binomial system and binomial names are agreed between biologists at international congresses.

Explanation​:
Uracil and thymine are nitrogenous bases found in two types of nucleic acids: DNA and RNA.

Uracil is found in RNA, whereas thymine is found in DNA. (Choice B)

Uracil pairs with adenine in RNA and thymine pairs with adenine in DNA (Choice D).

In both DNA and RNA, these nitrogenous bases are joined to a five-carbon sugar, also called a pentose sugar which has a ring structure, so Choice A is incorrect.

Both uracil and thymine are pyrimidines which are single-ring structures (Choice C). Adenine and guanine are purines which consist of two rings.

Explanation​:
RNA is believed to be a potential candidate for the first genetic material due to its ability to form spontaneously from nucleotides (Statement I). Miller's famous experiment demonstrated that simple organic molecules, including nucleotides, could be produced from a mixture of gases under conditions that simulated early Earth (Statement III). This experiment suggested that nucleotides could have formed spontaneously on a prebiotic Earth, providing a plausible scenario for the emergence of RNA as the first genetic material. Therefore Choice B is correct.

Choice A only included Statement I and not II, so it is incorrect. While it is true that RNA contains ribose as its sugar component (Statement II), the presence of ribose is not a primary reason for RNA being considered the first genetic material. Both RNA and DNA contain sugars in their structures, but the key point in favour of RNA as the first genetic material is its ability to form spontaneously. Choices C and D included Statement II and so are incorrect.

Explanation​:
Choice D is correct because homologous structures refer to structures inherited from a common ancestor which are similar but often used for different functions.

Choice A is incorrect, as ancestral structures refer to structures present in an ancestor species, not structures found in present day species. Choice B is incorrect as convergent structures are not a term used in biology. Convergent evolution, on the other hand, leads to analogous structures. Choice C is incorrect as analogous structures refer to structures used for the same function, which are significantly different when closely inspected. Analogous structures also have different evolutionary origins.

Explanation​:
Gravity is responsible for holding water on Earth and is a fundamental factor in water retention within the planet's atmosphere and surface. Choice D is, therefore, correct.

Choice A is incorrect, as although rainfall is a part of the water cycle and is responsible for distributing water, it does not directly contribute to the retention of water on Earth.

Choice B is incorrect, as the moon's gravitational force regulates the tides of large bodies of water but does not directly contribute to water retention on Earth. Choice C is incorrect as water is lost from bodies of water on the surface of the Earth and evaporates into the atmosphere, which doesn't directly address water retention.

Explanation​:
Choice B is not true. Not all genes are expressed in each cell. Only the necessary genes are expressed based on the specialised function of the cell. All other statements are true.

Explanation​:
The chromosomes of eukaryotes are linear, and the DNA is coiled around histone proteins (Choice C). Choice A is incorrect because eukaryotic DNA molecules are not circular. Choice B is incorrect because eukaryotic cells do not have looped DNA in the nucleus. Choice D is incorrect because the linear DNA molecules in eukaryotic cells are coiled around histone proteins.

Explanation​:
A group of individuals living in a defined area is not a biological definition (Choice A). A group of individuals of the same species living in a given area at the same time who are interacting with each other is a population (Choice B) and the environment in which they live is a habitat (Choice C). It is only when they can interbreed to produce fertile offspring that they can be considered a species. (Choice D).

Explanation​:
Statement II is correct as prokaryotic cells do not have a Golgi apparatus and statement III is correct as prokaryotic cells do not have membrane bound organelles. Choices A, C and D are incorrect.

Explanation​:

Rewilding projects attempt to restore and rehabilitate ecosystems by reintroducing native species and allowing natural processes to become re-established. Statement I is therefore correct. Recycling and reusing products means fewer resources will be extracted from the Earth which is a process that can destroy natural habitats and lead to excessive landfill use, so Statement II is correct. Choice C is therefore correct (Statement I and II).

Increasing meat consumption (Statement III) results in more land being cleared for animals such as cattle to be bred, decreasing biodiversity. Choice D is therefore incorrect as it includes this statement. Choices A and B are missing one of the possible solutions to the crisis and are therefore incorrect.