Grade 11 AC Biology End of Year Study Guide

Variation, heredity, and differential survival and reproduction

<p>True</p> Signup and view all the answers

<p>time</p> Signup and view all the answers

<p>Common Ancestry = Principle that all organisms are related and descended from a common ancestor Speciation = Process where new species evolve from existing species over time Natural Selection = Mechanism of evolution involving survival and reproduction of advantageous traits</p> Signup and view all the answers

<p>The 'primordial soup' hypothesis suggests that life began in a warm, nutrient-rich environment where simple organic molecules formed and eventually combined to create more complex molecules, leading to the first living cells.</p> Signup and view all the answers

<p>The Miller-Urey experiment demonstrated that organic molecules necessary for life, such as amino acids, could be synthesized from inorganic precursors under conditions thought to resemble the early Earth's atmosphere.</p> Signup and view all the answers

<p>Phototropism is the growth response of plants towards or away from light. It benefits plants by directing their growth towards light sources, maximizing photosynthesis and ensuring efficient energy capture for growth and development.</p> Signup and view all the answers

<p>Auxins are plant hormones that regulate growth. In phototropism, auxins accumulate on the shaded side of the plant, causing cells to elongate more on that side, bending the plant towards the light source.</p> Signup and view all the answers

<p>Photoperiodism is the response of plants to the length of day and night, affecting flowering. Long-day plants flower when nights are short, while short-day plants flower when nights are long. Day-neutral plants flower regardless of day length.</p> Signup and view all the answers

<p>Phytochrome is a light-sensitive pigment that helps plants detect changes in light quality and duration. It exists in two forms, Pr and Pfr, which interconvert based on light conditions. The ratio of these forms helps plants measure day length and trigger appropriate physiological responses, such as flowering.</p> Signup and view all the answers

<p>Plants exposed to shorter nights (longer daylight) will flower sooner than plants exposed to longer nights (shorter daylight). Divide plants into three groups with different light durations: long-day (16 hours of light), short-day (8 hours of light), and control (12 hours of light). Use timers to regulate the light exposure for each group. Maintain consistent temperature and watering for all groups. Monitor and record the flowering time for each plant. Control group: Plants exposed to 12 hours of light and 12 hours of dark.</p> Signup and view all the answers

<p>Natural selection is the process by which individuals with favorable traits are more likely to survive and reproduce, passing those traits to the next generation. Example: Peppered moths in England where darker moths became more common due to industrial soot darkening trees. Artificial selection is the process by which humans select and breed individuals with desired traits. Example: Breeding dogs for specific characteristics such as size, coat color, or temperament.</p> Signup and view all the answers

<p>Natural selection leads to adaptation by favoring individuals with traits that enhance their survival and reproductive success in a particular environment. Over time, these advantageous traits become more common in the population, leading to a better-suited population for the environment.</p> Signup and view all the answers

<ol> <li>Fossil Record: Provides chronological evidence of past life forms and shows changes over time, supporting the idea of common ancestry and gradual evolution. 2. Comparative Anatomy: Homologous structures (similar structures in different species) indicate common ancestry, while analogous structures (different structures with similar functions) show convergent evolution.</li> </ol> Signup and view all the answers

<p>Molecular biology allows scientists to compare DNA and protein sequences between different organisms. Similarities in genetic material provide evidence of common ancestry and help reconstruct evolutionary relationships and timelines.</p> Signup and view all the answers

<p>Common ancestry refers to the idea that all living organisms share a common ancestor at some point in their evolutionary history. This concept is depicted in the tree of life, where branches represent lineages that diverged from common nodes (ancestors), illustrating the relationships among different species.</p> Signup and view all the answers

<p>An example of a homologous structure is the forelimb bones of vertebrates, such as the human arm, the wing of a bird, and the flipper of a whale. These structures have different functions but share a similar underlying bone structure, indicating a common ancestor.</p> Signup and view all the answers

<p>Speciation is the process by which new species arise from existing ones. The two main types are: 1. Allopatric Speciation: Occurs when populations are geographically separated, leading to reproductive isolation and divergence. 2. Sympatric Speciation: Occurs without geographic separation, often through genetic mutations, polyploidy in plants, or behavioral changes that lead to reproductive isolation.</p> Signup and view all the answers

<p>Reproductive isolation prevents gene flow between populations, allowing them to evolve independently. Over time, genetic differences accumulate, leading to the formation of new species.</p> Signup and view all the answers

<p>The primary causes of extinction include habitat destruction, climate change, overexploitation, invasive species, and pollution.</p> Signup and view all the answers