AP Biology Topic 3.7 Fitness PDF

AP biology Topic 3.7 Fitness In your own words: What does Fitness refer to in biology?  What does Fitness refer to? In a biological context, fitness refers to an organism’s ability to survive, reproduce, and pass its genes to the next generation...

AP biology Topic 3.7 Fitness In your own words: What does Fitness refer to in biology?  What does Fitness refer to? In a biological context, fitness refers to an organism’s ability to survive, reproduce, and pass its genes to the next generation in its environment. “How well it “fits” the environment.”  What does Fitness refer to? Higher fitness means that an organism is better adapted to its environment and more likely to produce offspring that will also survive and reproduce. What factors or characteristics do you think might increase an organism’s fitness? Great fitness for Poor fitness for here here  Variation increases FITNESS …. Individuals with traits that improve survival and reproduction are more 'fit.’ Variation provides these advantageous traits, boosting the population's overall adaptability and fitness." Fitness and Variation at Molecular level Molecular Variation Impact on Fitness Molecular variation can directly It includes differences in DNA sequences, protein structures, enzyme influence an organism's fitness by activities, and types of molecules impacting vital processes like (such as lipids, carbohydrates, etc.) metabolism, growth, and within cells. reproduction. 1) Hemoglobin Variation 2) Chlorophyll Variation in Plants 3) Phospholipid Variation in Cell Membranes Standard: Naturally occurring diversity among and between components within biological systems affects interactions with the environment. ESSENTIAL KNOWLEDGE: Different types of SYI-3.A.1 phospholipids Variation at the molecular level provides organisms with the ability to respond to a variety of environmental stimuli. SYI-3.A.2 Variation in the number and types a of molecules within cells provides b organisms a greater ability to survive and/or reproduce in different environments. Different types of  Molecular Variation in Hemoglobin Definition Variation in hemoglobin types adapts to different oxygen needs and environments. Fetal Hemoglobin (Hemoglobin F) Binds oxygen more strongly than adult hemoglobin. Allows efficient oxygen transfer from mother’s blood to fetus. Adult Hemoglobin (Hemoglobin A) Replaces hemoglobin F after birth. Suited for oxygen transport in a higher-oxygen environment. Purpose of Hemoglobin Variation Enables hemoglobin to meet specific oxygen demands at different life stages. At the placenta the fetal Adapts to environmental conditions for optimal oxygen haemoglobin can ‘steal’ delivery. oxygen form the maternal haemoglobin. Fetal haemoglobin The dissociation curve of fetal Hb is to the left of adult Hb. This means fetal Hb combines with oxygen more readily than adult Hb. Fetal Hb has a higher affinity for oxygen.  Molecular Variation in Phospholipids Fatty acids can be Or Fatty acids can be saturated with straight unsaturated with bent or hydrocarbon chains kinked hydrocarbon chains Saturated fats tend Unsaturated fats to be solid at room tend to be liquid at temperature room temperature Therefore, the % composition of saturated vs unsaturated fatty acids in a lipid bilayer influences the fluidity of the membrane. But why does this matter? More viscous, less Highly fluidity  Plants live rooted in one place throughout different If they had a high % seasons. of saturated fatty In summer, or acids in winter, their hotter cell membranes temperatures, would solidify, they can therefore, they have decrease the % the ability to increase of unsaturated the % of unsaturated fatty acids and fatty acids to ensure increase % of their membranes saturated fatty maintain fluidity for acids. easier passive transport. The ability to change the composition of their cell membranes helps them respond to a variety of environmental stimuli.  Molecular Variation in Chlorophyll absorbs light mainly in absorbs light best in the blue-violet and red the blue and red-orange regions. regions. a b Photosystem II Photosystem I Chlorophyll a chlorophyll b The two different chlorophyll molecules specialize in absorbing different wavelengths of light which increase the ability to absorb solar