Living Earth Spring Final Review

Chromosome

A structure that contains genetic material, consisting of chromatids, a centromere, telomeres, and genes.

Homologous chromosomes

Pairs of chromosomes that have the same genes in the same order, one from the mother and one from the father.

Gene

A segment of DNA that codes for a specific trait, found on chromosomes.

Crossing over

The exchange of genetic material between homologous chromosomes during meiosis, leading to genetic recombination.

Nondisjunction

The failure of chromosomes to separate properly during meiosis, potentially causing aneuploidy.

Monohybrid cross

A genetic cross between individuals involving one pair of contrasting traits.

Karyotype

A visual representation of an individual's chromosomes, showing 46 chromosomes in humans.

Dominant traits

Traits that are expressed when at least one allele for that trait is present.

Recessive traits

Traits that are expressed only when two alleles for that trait are present.

Allele

A variant form of a gene.

Homozygous genotype

A genotype in which both alleles for a trait are the same.

Heterozygous genotype

A genotype in which the alleles for a trait are different.

Gregor Mendel

A scientist who discovered the basic principles of heredity through pea plant experiments.

Phenotype

The observable characteristics of an organism.

Genotype

The genetic makeup of an organism.

Codominance

A condition where both alleles in a heterozygous individual are expressed.

Blood types

The different types of blood, including A, B, AB, and O, related to codominance.

Physical weathering

The process of breaking down rocks without changing their chemical composition.

Chemical weathering

The process of breaking down rocks by changing their chemical composition.

Biological weathering

The process of breaking down rocks by living organisms.

Deforestation

The removal of trees, which can lead to increased soil erosion.

Ring of Fire

A region around the Pacific Ocean known for its volcanoes and plate boundaries.

Convergent boundaries

Plate boundaries where tectonic plates collide.

Divergent boundaries

Plate boundaries where tectonic plates move apart.

Transform boundaries

Plate boundaries where tectonic plates slide past each other.

Natural selection

The process by which differential survival and reproduction due to variations in traits leads to evolution.

Adaptations

Traits that enhance an organism's survival and reproduction in its environment.

Adaptive radiation

The diversification of a group of organisms, such as Darwin's finches, into different species.

Artificial selection

The selective breeding of plants and animals by humans to produce desired traits.

Homologous structures

Structures in different species with a similar underlying anatomy but different functions.

Vestigial structures

Body structures that have lost their original function over time.

Cladogram

A diagram that shows evolutionary relationships among a group of organisms.

Mutation

A change in the DNA sequence that can introduce new genetic variation into a population.

Gene pool

The total collection of genes in a population at any one time.

Abiotic

Non-living components of an ecosystem.

Biotic

Living components of an ecosystem.

Carrying capacity

The maximum population size that an environment can sustain.

Density-dependent factor

A limiting factor that depends on population size.

Niche

The role an organism plays in its environment, including habitat and food sources.

Symbiotic relationship

A close and long-term interaction between two different species.

Producer (autotroph)

An organism that makes its own food.

Consumer (heterotroph)

An organism that eats other organisms.

Food chain

A linear sequence of organisms through which nutrients and energy pass.

Food web

A network of interconnected food chains.

Rule of 10%

The principle that only about 10% of the energy at one trophic level is passed to the next.

Resistance

The ability of a population to withstand disturbance.

Resilience

The ability of a population to recover from disturbance.

Biomagnification

The increasing concentration of toxins in organisms at higher trophic levels.

Climate

The long-term average of weather conditions in a region.

Sustainable agriculture

Farming practices that meet today's needs without compromising future generations' needs.