Answer:
Allele frequency can be described as a phenomenon which measure how common an allele is in a particular population. It tells about the genes which are richest in a gene pool and it also shows the genetic diversity in a population. Allele frequency is often expressed in percentages.
Natural selection tends to favour those organisms that are best adapted to live in an environment and which can withstand changes occurring in the ecosystem. If due to some circumstances, a trait becomes less useful to organisms in a population then by natural selection the allele frequency for those alleles will reduce with time. Similarly, the alleles which code for better genes for an environmental change will be increased due to the phenomenon of natural selection.
 
        
                    
             
        
        
        
Blood always flows through the system in the same pattern: coming from the body, passing through the right side of heart, then out to the lungs to receive oxygen, then passing back through the left side of the heart and then traveling out to the body.  Heart valves help to keep the blood flowing properly to each important destination of the circulation journey.
        
             
        
        
        
Cell membrane: Scattered in the lipid bilayer are cholesterol molecules, which help to keep the membrane fluid consistent. Membrane proteins are important for transporting substances across the cell membrane. They can also function as enzymes or receptors. On the extracellular fluid side of a cell membrane, you find carbohydrates.
Cytoplasm: Function of Cytoplasm. The jelly-like fluid that fills a cell is called cytoplasm. It is made up of mostly water and salt. Cytoplasm is present within the cell membrane of all cell types and contains all organelles and cell parts.
Nucleus: Function of the Nucleus. The nucleus is an organelle found in eukaryotic cells. Inside its fully-enclosed nuclear membrane, it contains the majority of the cell's genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes.
Cell wall: The cell wall is the protective, semi-permeable outer layer of a plant cell. A major function of the cell wall is to give the cell strength and structure, and to filter molecules that pass in and out of the cell.
        
             
        
        
        
Answer:
<u>Living things are derived from single units and show several characteristics such as growth respiration, response to stimuli, homeostasis, evolution, and reproduction.</u>
Explanation:
The natural world comprises several biotic or living and abiotic, non-living factors. Cells, are considered the smallest unit capable of supporting life.  All living, or biotic factors must be able to grow, carry out respiration- a process that produces energy, and reproduce (pass on genes). They also  show some level of organization or complexity, and respond to stimuli. Additionally, living organisms exhibit homeostasis or control over their internal environment and evolve or change over time to adapt to their external environments.