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Schistosomiasis, also known as bilharzia or snail fever, is a parasitic disease caused by blood flukes that live in freshwater snails. The larval form of the parasite, called cercariae, emerges from the snail and contaminates water. People become infected when their skin comes into contact with the contaminated water. Treating water sources with chemicals to kill snails (molluscicides) can reduce the number of infective larvae.This will help control the snails.

The central nervous system (CNS) is made up of the brain and spinal cord: Brain: Controls how we think, feel, move, and learn. Spinal cord: Carries messages between the brain and the nerves that run throughout the body.

I - Paramylum granules II - Contractile vacuole III- Chloroplasts IV- Nucleus The chloroplasts is the plant-like feature of euglena, which enables it to carryout photosynthesis.

The type of reproduction in Paramecium is asexual binary fission in which a fully grown organism divides into two daughter cells. Paramecium also exhibits several types of sexual processes.

Glycolysis is the first step in cellular respiration and occurs in the cytoplasm of cells. It's a series of ten enzymatic reactions that break down glucose into pyruvic acid. In glycolysis, glucose is broken down through a series of enzyme-catalyzed reactions to produce pyruvate, ATP, and NADH

In unicellular organisms such as amoeba and paramecium exchange of gases takes place through plasma membrane(also known as the cell membrane, the plasma membrane is found in all cells and separates the cell's interior from the outside environment) by simple diffusion. In earthworm, leech and frogs exchange of gases takes place through their moist skin. Flatworms are small, simple organisms that lack specialized circulatory and respiratory systems. Their flat shape and moist cells allow for quick diffusion of gases across their outer membrane(the outer membrane is made up of phospholipids, proteins). This process is called direct diffusion. Gaseous exchange in earthworms takes place through their moist skin and capillaries, not through the plasma membrane. Earthworms don't have respiratory organs, so they exchange gases through their skin in a process called cutaneous respiration. The skin is covered with a thin layer of mucus that keeps the body moist and creates an environment for gas exchange.

Secondary succession is a natural ecological process that occurs when an area is disrupted, but some plants and animals still survive. A characteristic of secondary succession is that it starts on an already colonized surface. It may start with fairly complex organisms and it takes a shorter time or duration to reach a climax community.

One of the components of xylem tissue is tracheids. Tracheids are Long, tube-like cells with lignified walls and tapering ends that overlap with adjacent cells. Tracheids are dead and non-protoplasmic. Companion cells are living cells in plants that are associated with sieve tube members in the phloem. They are responsible for loading and unloading sugars, and transporting macromolecules and signaling molecules.They are not found in Xylem tissue but exclusively in phloem. Also, sieve tubes are found in phloem while Xylem and phloem is a vascular tissue and an example of complex tissues, and not epidermal tissue.

The theory of natural selection, proposed by Charles Darwin, states that individuals with favorable traits are more likely to survive, reproduce, and pass those traits on to their offspring. Conversely, individuals with unfavorable traits are more likely to struggle, die off, or fail to reproduce, thereby eliminating those traits from the population. In other words, natural selection acts on the variation within a population, favoring individuals with traits that enhance their survival and reproductive success, while eliminating those with traits that hinder their ability to survive and reproduce. So, option C accurately reflects this concept. A. "There is no struggle for existence" is the opposite of what natural selection proposes. B. "New species get better adaptation" is a consequence of natural selection, but it doesn't explain the mechanism. D. "Unused structures disappear later" refers to the concept of vestigial structures, which is related to evolution, but not a direct explanation of natural selection.

The formula for population density is Dp = \(\frac{N}{A}\) , where: Dp = The population density N = The total number of individuals in the population A = The area, which can be measured in any land area unit, such as acres, meters, centimeters, or miles Given: N = 2,310,000people , A = 2,310 km\(^2\) Dp = \(\frac{N}{A}\) = Dp = \(\frac{2,310,000}{2,310}\) = 1,000

Primary succession is the ecological succession that occurs in an area where there is no pre-existing community. Primary succession is the process of colonization that begins when an area has no plant life, such as after a volcanic eruption or glacial retreat.

Photosynthesis is the process that releases oxygen into the atmosphere. Photosynthesis is a process that uses light energy from the sun to convert water and carbon dioxide into oxygen and organic compounds. This process is performed by green plants and certain other organisms, including phytoplankton in the oceans.

The depressed side of a paramecium that is lined with cilia leads to a tube-like structure called the buccal cavity, also known as the gullet.

The rhizoids of liverworts are unicellular and unbranched. Rhizoids are root-like structures that anchor liverworts to the ground. In contrast, mosses have multicellular rhizoids. In vascular plants, rhizoids are often called root hairs and can be unicellular or multicellular.

Climatic factors are environmental conditions that affect the climate of a region, such as temperature, precipitation, and solar radiation. Topographic factors are the features of the Earth's surface, such as its elevation, slope, and curvature. The chemical and physical composition of soil is an example of an edaphic factor. Edaphic factors are abiotic factors that relate to the chemical or physical composition of soil in a specific area. E.g texture, porosity, bulk density etc Chemical factors of soil include the concentrations of chemicals in the soil, the pH level, and the soil's cation exchange capacity.