Unit 9: The Spread of Viral Diseases and Body Systems Overview

Virus

A non-living, infectious particle that causes disease.

Pathogenic

Disease-causing.

Virion

One viral particle.

Host Cell

A cell that a virus or bacteria infects and uses to grow and reproduce.

Lytic Cycle

Virus infects the host cell, uses host cell machinery to replicate new viral particles, then lyses the cell to release viral particles.

Lysogenic Cycle

Virus infects the host cell, then has a latent/dormant stage where the viral genome is added to the host cell's genome and is replicated each time the host cell replicates.

Environmental Stressors

Factors like UV radiation, chemical exposure, and starvation that can trigger the lytic cycle.

Virus Reservoir

A host organism in which an infectious agent, which is pathogenic for some other species, lives and reproduces.

Vector

An organism that transmits the virus from a reservoir to another host.

Viral Transmission

The process by which a virus spreads, including respiratory droplets, aerosols, vectors, bodily fluids, and fomites.

Fomites

Objects or materials likely to transfer infectious particles (clothes, utensils, furniture, etc.).

Epidemic

An outbreak of a disease that affects a specific community at a particular time.

Pandemic

An outbreak of a disease that occurs over a wide geographic area (multiple countries/continents) and affects a significant proportion of the population.

Immune Response

The ability of organisms to attack viral particles directly or build defenses on potential host cells to prevent viral attachment.

Antibodies

Proteins created by the immune system when exposed to a virus, which help to prevent infection or reinfection.

Vaccines

Used for prevention of viral infections by allowing an organism to develop antibodies without actually being infected.

Antivirals

Medications used to treat viral infections, but there are few available and most have harsh side effects.

Levels of Organization

The hierarchy of biological organization: Cells, Tissue, Organ, Organ system, Organism.

11

Number of body systems in human body

Body systems

Cardiovascular (circulatory), respiratory, excretory, reproductive, digestive, nervous, muscular, skeletal, endocrine, integumentary, lymphatic (immune).

Homeostasis

The process by which organisms maintain a relatively stable internal environment

Osmosis

Moves water to balance the salt concentrations on either side of the cell membrane.

Competition and symbiotic relantionships

How an ecosystem maintains Homeostasis

Regulation

Management or control of animal body systems to maintain homeostasis.

Nutrient absorption

The breakdown of nutrients taken in by organism, then transported to cells for cellular processes.

Reproduction

Production of gametes and offspring.

Defense from injury

Protection from an organism's external environment.

Defense from illness

Protection from infection by pathogens.

Negative feedback

Response that decreases the function of a system.

Positive feedback

Response that increases the function of a system.

Estrogen and progesterone.

Which hormones regulate the female reproductive system?

Skeletal system

Protects vital organs.

Integumentary system

Acts as a barrier preventing pathogens from entering the body.

Immune system

Produces antibodies to target and fight pathogens; White blood cells are produced in the bone marrow.

Circulatory system

Transports immune cells to target pathogens throughout the body.

Photosynthesis

The process by which autotrophic organisms convert light energy into chemical energy, stored in the chemical bonds of the glucose molecule.

Chloroplasts

Site where photosynthesis takes place in primarily leaf cells.

ATP

Cellular energy produced from the breakdown of glucose through cellular respiration.

Starches

Form in which plants store energy by combining glucose monomers.

Cellulose

Material built from glucose monomers for the cell wall.

Vascular Plants

Plants with specialized tissues for transporting water and nutrients.

Angiosperms

Flowering plants that produce seeds that become 'fruit.'

Gymnosperms

Non-flowering plants that produce seeds in cones.

Non-Vascular Plants

Plants such as mosses that do not have specialized tissues for transporting water and nutrients.

Root System

Part of the plant, typically below the soil, that transports water and minerals, anchors the plant, and stores sugars.

Tap root

Large, central root that other roots sprout laterally from.

Fibrous root

Thin, branching roots growing from the stem.

Root hairs

Extensions of epidermal cells that increase the root surface area for better absorption of materials.

Shoot System

Plant structures above the soil with varying functions.

Leaves

Site of photosynthesis and gas exchange.

Stems

Supports the plant and holds it upright, while transporting water and sugars.

Flowers

Reproductive structure of angiosperms.

Seeds

Embryo of a plant.

Fruit

Develops from a ripened ovary and contains seeds; method of seed dispersal.

Vascular tissues

Found in both root and shoot systems to transport materials throughout the plant.

Xylem

Transports water from the roots upwards.

Phloem

Transports sugars from leaves downward.

Tropisms

Growth responses towards (positive) or away from (negative) a certain environmental stimulus.

Geotropism

Growth in response to gravity.

Phototropism

Growth in response to light, regulated by auxin.

Hydrotropism

Growth in response to water.

Thigmotropism

Growth in response to touch.

Nastic movement

Reversible movement in response to touch, not a growth response.

Nutrient absorption

Ex: Food is taken in by the digestive system, then broken down with the help of enzymes produced by structures of the endocrine system, then transported to cells via the circulatory system.

Systems for Reproduction

Male reproductive system, female reproductive system, endocrine system

Testosterone

Which hormone regulates the male reproductive system?