Biology Chapter on Species and Genetics

Prezygotic barriers prevent fertilization from occurring, such as habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, or gametic isolation. Postzygotic barriers occur after fertilization, such as reduced hybrid viability, reduced hybrid fertility, or hybrid breakdown.

A gene is a sequence of DNA that codes for a specific protein, while an allele is a variant form of that gene. Different alleles can lead to differences in the protein produced, which in turn can affect the organism's traits.

A habitat is the general environment where an organism lives, including its physical features like topography, soil, and climate, while a niche is the specific role or function an organism plays within that ecosystem, including its interactions with other organisms and its resource utilization.

<p>The five conditions required for Hardy-Weinberg Equilibrium are: 1. No mutations, 2. No gene flow, 3. Random mating, 4. Large population size, and 5. No natural selection.</p> Signup and view all the answers

<p>A vicariance event, such as the formation of a mountain range or a river, can geographically isolate two populations of a species. Over time, the isolated populations will evolve independently due to different selective pressures and genetic drift, eventually becoming distinct species.</p> Signup and view all the answers

<p>Chemosynthesis is a process where organisms use energy from inorganic chemical reactions, such as the oxidation of hydrogen sulfide or methane, to produce organic compounds. This process is crucial in ecosystems where sunlight is scarce, allowing organisms to thrive in environments like deep-sea hydrothermal vents and some caves.</p> Signup and view all the answers

<p>Synonymous mutations are mutations that do not change the amino acid sequence coded for by a gene, while nonsynonymous mutations do change the amino acid sequence. Synonymous mutations are often considered neutral, while nonsynonymous mutations can have a range of effects, from minimal to significant, on the organism's phenotype.</p> Signup and view all the answers

<p>Three types of mutations include: 1. Substitution mutations swap one base pair for another, potentially leading to a change in the amino acid sequence and the protein's function. 2. Deletion mutations remove a base pair from the sequence, causing a frameshift mutation that alters the reading frame and potentially disrupts the protein's structure and function. 3. Insertion mutations add a base pair to the sequence, also causing a frameshift mutation that can lead to a dysfunctional protein. Mutations can have varying consequences, ranging from no effect to detrimental or even advantageous for the organism.</p> Signup and view all the answers

A group of interbreeding organisms with similar characteristics.

A species that reproduces through a female-only lineage.

Reproductive obstacles that occur before fertilization.

A long strand of genetic material, which can be circular.

Coding sections of DNA that produce proteins.

Different forms of a gene that can vary among individuals.

The specialized role an organism plays in its ecosystem.

Any change in the structure of a gene or chromosome.