### structure:

Age structure
* is essential information for monitoring a population's status and recruitment history.
* is the distribution of numbers of individuals of various ages
  - number of individuals of each age within the population
  - uniform and timing of phenological events are uniform, e.g., flowering
  - useful in understanding and predicting population growth
* refers to the relative proportion of individuals in each age group of a population.

Analogous structure
* are structures that are similar in related organisms.
* don t have a common evolutionary origin.
* form in periglacial regions on Earth.
* serve functions
  - similar functions

### structure:

Apartment
* Some apartments are villas that are rented by the owners who act as landlords.
* are buildings
  - films
  - housing
* are located in apartment buildings
  - complexs
  - budget
  - towns
* are part of apartment buildings
  - individual houses which are occupied by the owners
  - suites
  - the most common type of housing
* are used for dwellings
  - parties
  - shelter
  - where the child goes to get away from the parent, to continue the segue to adulthood
* have balconies
  - doors
  - kitchens
* includes bases
  - ceilings
  - floors
  - room light
  - sections
  - walls

### structure | apartment:

Duplex
* Some duplexes have basements.
  * ' are dwellings containing apartments for two different households. The term 'duplex' however, is not used in some cities or towns, particularly Detroit, Dallas or Chicago. Duplexes are usually two-unit buildings. Some duplexes have basements. Others do not.
* are apartment buildings
* are located in major cities
  - projects
  - two living units in one building, either side by side or one on top of the other
  - used for families
* contribute to housing affordability.
* is an apartment

Suite
* are apartments.
* are located in hotels
  - motels
  - musical compositions
  - sets
* refer to a four-person room with private bath facilities.

### structure:

Aquarium
* All aquariums tend to grow algae.
* Aquaria contain fish
  - natural sediments
  - water
  - display jellyfish
  - exhibit turtles
* Aquaria fill with chlorine water
  - free chlorine water
  - pond water
* Aquaria have kinds
  - lids
  - oxygen
  - vent lids
* Aquaria includes bases
  - brims
  - sections
* Aquaria use filtration
  - sponge filtration
* Most aquaria contain fish
* Most aquaria have kinds
* Some aquaria absorb radiation.
* Some aquaria contain mangroves
  - red mangroves
  - sick guppies
* Some aquaria fill with run seawater
* Some aquaria have alga mats
  - animals
  - fluorescent tubes
  - thick mats
  - watt tubes
  - help humidity
  - aquariums provide models of sea animals for children to play on as a nice change of pace
* allow a deep layer of bedding so the gerbils can burrow.
* are a fun and interesting way of watching fish and how they live
  - facilities
  - generally balanced and fully contained ecosystems
  - heavier than wire cages and thus more difficult to move or tilt for cleaning
  - now a common source of infection
  - one of the most popular hobbies in the world
  - tanks
  - unsuitable housing for ferrets
* are used for fish
  - holds
  - houses
  - video games
  - vivariums
* come in many shapes and sizes.
* give youngsters a firsthand look at life in our oceans and lakes.
* have filters
* inevitably become 'eutrophic' with age.
* make efficient and aesthetic containers
  - great cages for rats since they are very easy to clean and disinfect
* perform a vital role educating people about aquatic conservation.
* typically have a solid glass or plexi-glass base and sides.
* work well for housing reptiles.

### structure | aquarium:

Freshwater aquarium
* Some freshwater aquaria have growth.
* are also a little more tolerant to lack of cleaning.