Explanation​:
Asteroids from space, which contained ice, arrived on Earth. This is the most accepted theory for the origin of water on Earth. This theory, often referred to as the "Late Heavy Bombardment" theory, suggests that during the early stages of the Solar System's formation, a significant number of asteroids and comets, some of which contained water in the form of ice, bombarded the Earth. Over time, as these icy bodies collided with Earth, they contributed to the accumulation of water on the planet's surface. Choice A is correct.

Choice B is incorrect, as water was present on Earth before early organisms were present. Choice C is incorrect because free oxygen atoms were absent in the early atmosphere. Choice D is incorrect because liquid water would need to be present on Earth before it could be converted into steam.

Explanation​:
Prokaryotic cells do not contain mitochondria but eukaryotic cells do. Choice D is correct.

Choice A is incorrect as eukaryotes (as well as Archae) contain 80S ribosomes. Choice B is incorrect as both eukaryotic and prokaryotic cells contain a plasma membrane. Choice C is incorrect as eukaryotic cells contain a nucleus but prokaryotic cells do not.

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​:
All 64 codons of the genetic code are present in all organisms, apart from minor variations indicating that all life evolved from the same original cells (Choice D).

Eukaryotic cells evolved from prokaryotic cells (Choice A) is incorrect as this is the endosymbiotic theory. Choice B is incorrect as mitochondria do not have a cell wall. Choice C is incorrect as bacteria do not have histones.

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​:
Choices A, B and D are incorrect as they all have a single membrane.

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​:
Choice A - Excretion is the process wherein waste and excess water in the organism are removed. Paramecia expel waste products such as carbon dioxide through the process of diffusion.

Choice B - Homeostasis pertains to the ability of living things to maintain a stable internal environment. Paramecia maintain a stable internal condition by expelling excess water using the contractile vacuole.

Choice C - Reproduction is the biological process by which organisms produce offspring that are biologically similar to themselves. Paramecia can reproduce sexually through meiosis and asexually through mitosis.

Choice D - Metabolism refers to all the chemical reactions in organisms such as anabolic and catabolic reactions. Paramecia produce enzymes that catalyse different catabolic and anabolic reactions in the cell.

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​:
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​:
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 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​:
Ribosomes carry out protein synthesis, not the Golgi apparatus. Choice A is correct. Choices B, C and D are incorrect as they are all functions of the Golgi apparatus.

Explanation​:
Choice D is correct because organisms placed in the same group share common ancestry. Choice A and Choice B are incorrect because morphology and anatomical characteristics are used to describe the structures of organisms which are used to primarily group them together. Choice C is incorrect because modes of nutrition are used to describe organisms but not to classify organisms.

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​:
Isotopes with long half-lives (Choice C), such as uranium and potassium isotopes, are often used in absolute dating because they decay slowly and are suitable for dating older fossils.

Stable isotopes (Choice A) are not used for fossil dating because they do not undergo radioactive decay. Absolute dating relies on the measurement of the decay of radioactive isotopes into stable daughter isotopes to determine the age of a sample. Isotopes with short half-lives (Choice B) are typically used for dating more recent events, not older fossils. Isotopes with no half-lives (Choice D) cannot be used for fossil dating using the methods based on radioactive decay. Isotopes without half-lives do not undergo radioactive decay, so it is impossible to establish a chronology or estimate the age of a fossil using these isotopes.

Explanation​:
The endosymbiotic theory states that larger prokaryotes engulfed smaller prokaryotes, which were the ancestors of modern chloroplasts and mitochondria, eventually evolving into eukaryotes. Choice A is correct.

Statement I (Choices B and D) is incorrect as prokaryotes were not formed by the endosymbiotic theory. Statement III (Choice C) is incorrect as spontaneous generation is impossible.

Explanation:
X is pointing to the nucleus and Y is pointing to a mitochondrion. Choice A is incorrect as neither organelle has a single membrane. Choice B is incorrect as only mitochondria contain cristae, the nucleus does not. Choice D is incorrect as neither the nucleus or mitochondria contain starch grains.

Explanation​:
Choice D is correct. The DNA sequence (Statement I) and amino acid sequence (Statement II) are the usual, present way of determining members of the same clade, however, physical appearance (Statement III) was previously, but is now rarely, used.

Explanation​:
Choice B is the correct definition for a clade, a group of organisms that share a common ancestor. Choice A and C are incorrect as they do not feature the idea of a common ancestor. Choice D is incorrect because organisms within a clade do share a common ancestor.

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:
Water's thermal properties (Choice A) include a high heat of vaporisation which results in the absorption of a large amount of heat by water before changing its physical state. This means that changing the temperature of the water is slow, and this helps to maintain the internal temperature of organisms between set limits.
Water has cohesive properties (Choice B) which means it sticks to other water molecules.
Water has adhesive properties (Choice C) which means it adheres to charged surfaces.
Water is an excellent solvent (Choice D) which means it dissolves a wide array of polar and ionic substances.

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:
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​:

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.