Science Review: Genetics, Ecology, and Waves

Vocabulary practice flashcards covering fundamental concepts in DNA, inheritance, cell division, ecology, and wave physics.

DNA

The molecule that stores genetic instructions.

Gene

A section of DNA that contains instructions for a functional product, often a protein.

Chromosome

A long, organised DNA molecule containing many genes.

Genome

The complete set of genetic material in an organism.

Nucleus

The part of most human cells where most DNA is stored.

Allele

A version of a gene.

Trait

A characteristic of an organism, such as blood type or eye colour.

Mitosis

A type of cell division that produces two daughter cells that are genetically very similar to the original cell, maintains the chromosome number, and is used for growth and repair.

Meiosis

A type of cell division that produces four genetically different sex cells with a halved chromosome number for sexual reproduction.

Sexual reproduction

A form of reproduction involving the joining of genetic material from two sex cells, producing genetically varied offspring due to different combinations of alleles.

Asexual reproduction

A form of reproduction involving one parent that does not involve the joining of sex cells, producing offspring that are usually genetically identical to the parent apart from mutations.

Genotype

The alleles an organism possesses for a gene.

Phenotype

The observable characteristics produced by an organism's genotype and, in many cases, environmental influences.

Homozygous

Having two identical alleles for a gene, such as $BB$ or $bb$.

Heterozygous

Having two different alleles for a gene, such as $Bb$.

Dominant allele

An allele that can affect the phenotype when only one copy is present in a simple dominant-recessive inheritance pattern.

Recessive allele

An allele that affects the phenotype in a simple dominant-recessive pattern when two copies are present.

Punnett square

A diagram used to help predict the possible genotypes of offspring.

Inherited characteristics

Characteristics influenced by genetic information passed from parents, such as natural blood type.

Acquired characteristics

Characteristics that develop during an organism's lifetime due to experience or environmental influences, such as a scar or a skill learned through practice.

Genetic variation

Differences between individuals within a species, resulting from mutations, different combinations of alleles during meiosis, and the random joining of gametes during fertilisation.

Mutation

A change in DNA, which can be harmful, beneficial, or neutral.

Ecosystem

A biological community that includes living organisms and the non-living parts of their environment.

Biotic factors

Living components of an ecosystem, such as plants, animals, and bacteria.

Abiotic factors

Non-living components of an ecosystem, such as water, sunlight, temperature, and soil.

Biodiversity

The variety of living things in an area.

Food chain

A representation showing how energy passes between organisms.

Producer

An organism that makes its own food, usually through photosynthesis.

Consumer

An organism that obtains energy by eating other organisms.

Decomposer

An organism that breaks down dead organisms and waste, recycling nutrients.

Food web

Several connected food chains.

Predator

An organism that hunts other organisms.

Prey

An organism that is eaten by a predator.

Adaptation

An inherited feature that helps an organism survive and reproduce in its environment.

Structural adaptations

Adaptations that involve body features, such as thick fur in cold environments.

Behavioural adaptations

Adaptations that involve actions, such as migration.

Physiological adaptations

Adaptations that involve internal processes, such as producing concentrated urine to conserve water.

Wave

A disturbance that transfers energy from one place to another without permanently transferring matter overall.

Transverse waves

Waves in which the particles vibrate perpendicular to the direction the wave travels.

Longitudinal waves

Waves in which the particles vibrate parallel to the direction the wave travels, containing compressions and rarefactions.

Crest

The highest point of a transverse wave.

Trough

The lowest point of a transverse wave.

Amplitude

The maximum displacement from the resting position ($A$).

Wavelength

The distance between two matching points on a wave, such as crest to crest ($\lambda$).

Frequency

The number of complete waves passing a point each second ($f$), measured in hertz ($\text{Hz}$).

Period

The time taken for one complete wave ($T$), measured in seconds.

Reflection

The process where a wave bounces off a surface, with the angle of incidence equaling the angle of reflection.

Refraction

The process where a wave changes direction because its speed changes when it enters a different medium at an angle.

Normal

An imaginary line perpendicular to the surface at the point where the light hits.