Life Science Final Exam Study Guide Flashcards

Vocabulary-style flashcards covering genetics, body systems, and ecosystem concepts for a life science final exam.

Dominant allele

An allele that is always expressed if present (T).

Recessive allele

An allele that is only expressed if two copies are present (tt).

Genotype

The genetic makeup of an organism (ex: Tt).

Phenotype

The physical trait expressed by an organism (ex: tall plant).

Gene Location

Genes are located on chromosomes within the nucleus.

Meiosis

A type of cell division that produces sex cells (gametes) with half the number of chromosomes, increasing genetic variation.

Body cells

Cells that contain $46$ chromosomes, or $23$ pairs.

Sex cells (gametes)

Cells that contain $23$ chromosomes so that when they combine during fertilization, the offspring has $46$ total.

Sex-linked traits

Traits carried on sex chromosomes, usually the X chromosome, such as color blindness.

Mutation

A change in DNA that can be harmful, helpful, or have no effect on an organism’s quality of life.

mRNA Transcription Base Pairing

$$A \rightarrow U, T \rightarrow A, C \rightarrow G, G \rightarrow C$$

Crossing over

The process during meiosis where chromosomes exchange segments, creating new gene combinations.

Genetic diversity

Variations that increase a species’ ability to survive environmental changes and diseases.

Proteins

Molecules that build and repair tissues and act as enzymes.

Integumentary system

The system comprising the skin that releases sweat and adjusts blood flow to regulate body temperature.

Respiratory gas exchange

The process where oxygen enters the lungs and moves into the blood, while carbon dioxide leaves the blood and is exhaled.

Muscular and skeletal interaction

The relationship where muscles pull on bones to create movement.

Mechanical digestion

The physical breakdown of food, such as chewing.

Chemical digestion

The breakdown of food using enzymes and acids.

Small intestine

The organ responsible for absorbing nutrients into the bloodstream.

Double-loop pathway

The blood circulation route: Heart $\rightarrow$ lungs $\rightarrow$ heart $\rightarrow$ body $\rightarrow$ heart.

Oxygenated blood

Blood that is rich in oxygen.

Deoxygenated blood

Blood that is low in oxygen and high in carbon dioxide.

Niche

An organism’s specific role or job in an ecosystem.

Mutualism

An ecosystem relationship where both organisms benefit.

Commensalism

An ecosystem relationship where one organism benefits and the other is unaffected.

Parasitism

An ecosystem relationship where one organism benefits and the host is harmed.

Predation

An interaction where one organism kills another for food.

Resource partitioning

The practice of organisms using different resources, habitats, or times to reduce competition.

Primary succession

A type of ecological succession that starts from bare rock.

Secondary succession

A type of ecological succession that happens after a disturbance where soil remains.

Keystone species

A species that has a large impact on its ecosystem.

Invasive species

Non-native species that harm ecosystems by outcompeting native species.