Biology entrance exam, 2017 E.C. (2025)

The Institute of Biodiversity Conservation (today called the Ethiopian Biodiversity Institute) keeps one of the largest gene banks in Africa. A gene bank stores seeds and other genetic material so that Ethiopia's crop varieties and wild species are not lost. The other choices are a university department and medical research institutes; storing genetic resources is not their job.

Textbook: Biology Grade 12, Unit 1 Application of Biology, section 1.1 Application in conservation of natural resources (page 8).

Resolution is the power of a microscope to show two points that lie close together as two separate points. The dots looked well separated because of this resolving power. Magnification only makes an image larger; a big but poorly resolved image would still show the two dots as one blurred spot.

Textbook: Biology Grade 9, Unit 1 Introduction to Biology, section 1.5 Handling and using a light microscope.

Animal and plant cells are both eukaryotic, so they share the cell membrane, nucleus, cytoplasm, mitochondria and endoplasmic reticulum. The wrong options each smuggle in a structure that belongs to only one cell type: chloroplasts and the single large vacuole are found in plant cells, while lysosomes are typical of animal cells.

Textbook: Biology Grade 9, Unit 3 Cells, section 3.5 Animal and plant cells.

In the hypertonic solution (group I) the solution is more concentrated than the potato cells, so water leaves the cells by osmosis and the slice becomes flaccid (soft). In the hypotonic solution (group II) water enters the cells, so the slice becomes turgid (firm). Haemolysis happens only to red blood cells, which burst because they have no cell wall; potato cells are protected by their walls.

Textbook: Biology Grade 9, Unit 3 Cells, section 3.7 The cell and its environment.

Check each nutrient against the foods. Vegetables, banana and orange give plenty of carbohydrates, vitamins and minerals, and beans are a good plant source of protein. None of these foods contains much fat or oil, so lipids are the nutrient most likely missing from his diet.

Textbook: Biology Grade 9, Unit 5 Human health, nutrition and diseases.

Bile is made in the liver and released into the small intestine. It emulsifies fats, meaning it breaks large fat drops into many tiny droplets. This gives the fat a much larger surface area, so the enzyme lipase can digest it faster. Option A is wrong because proteins are digested by protease enzymes such as pepsin and trypsin, not by hydrochloric acid and amylase; most water is reabsorbed in the large intestine, and starch must be fully digested to glucose before it can be absorbed.

Textbook: Biology Grade 10, Unit 5 Human Biology, section 5.1 The digestive system.