ENT 101 MIDTERM 1 QUESTIONS WITH VERIFIED
ANSWERS
Insect represent what percent of all known species - Answers - over 50%
Vertebrates - Answers - have an internal skeleton (endoskeleton) with vertebrae
arranged into a spinal column
Invertebrates - Answers - no vertebrae (no internal support structure) they have support
outside their body (exoskeleton)
Two functions of the vertebral column - Answers - 1. Provides support against gravity
2. Allows for large body sizes
Vertebrate animals (5) - Answers - 1. Amphibians
2. Fish
3. Reptiles
4. Birds
5. Mammals
More than 90% of all species are what - Answers - invertebrates
Most recognized species of invertebrates - Answers - arthropods
Arthron - Answers - joint
Podos - Answers - feet
Arthropod means what - Answers - jointed appendages
Two functions of jointed appendages - Answers - 1. Locomotion
2. Modified for different structures (antennae, mouth parts, reproductive structures)
How many known species of arthropods are there - Answers - about 1.2 million
Arthropods include what groups (6) - Answers - 1. Crabs
2. Lobsters
3. Spiders
4. Scorpion
5. Millipedes
6. Centipedes
7. Insects
5 characteristics of arthropods - Answers - 1. Bilateral symmetry
,2. Segmented bodies
3. Ventral nerve cords
4. Dorsal blood vessels
5. Exoskeletons
Bilateral symmetry - Answers - split along the anterior-posterior axis (forming a single
plane of symmetry, separating into left and right sides)
Jellyfish almost have perfect of what type of symmetry - Answers - radial
3 main body axis - Answers - 1. Dorsal/ventral
2. Anterior/posterior
3. Lateral
Dorsal ventral axis - Answers - from top to bottom
Anterior posterior axis - Answers - from front to back
Lateral axis - Answers - from one side to another
Segmented body - Answers - fused into regions/tagmata with different biological
functions
Ventral nerve cord of arthropods is not enclosed in what - Answers - a protective spinal
column
What type of nerve cord do humans have - Answers - dorsal
What kind of circulatory system do humans have - Answers - closed
Open circulatory system of arthropods - Answers - don't have a network of blood
vessels, they have a single dorsal blood vessel with large openings at either end
In arthropods, tissues are directly exposed to what - Answers - blood
Exoskeleton two features - Answers - hard and flexible
Exoskeleton of arthropods is made up of what - Answers - cuticle and epidermis
Exoskeleton cuticle is made up of which two things - Answers - chitin and protein
3 layers of the exoskeleton cuticle - Answers - 1. Waxy epicuticle
2. Exocuticle
3. Endocuticle
Exocuticle is hardened by what - Answers - tanning
,Endocuticle features - Answers - unhardened and stretchy
Epidermis of exoskeleton lies where - Answers - below the endocuticle
Basement membrane of exoskeleton - Answers - thin tissue under epidermis
(separating it form the body cavity)
5 functions of the exoskeleton of arthropods - Answers - 1. Protects from damage
2. Reduces water loss
3. Site for muscle attachment
4. Barrier against microorganisms
5. Supports internal organs
Which part of the exoskeleton reduces water loss - Answers - the epicuticle
Which part of the exoskeleton acts as a barrier against microorganisms - Answers -
epicuticle
Tanning in exoskeleton - Answers - a crosslinking of proteins in the chitin protein matrix
(sclerotization)
Tanning in exoskeleton can be achieved how - Answers - by mineralization
Disadvantage of exoskeleton - Answers - limits growth (so they must moult to grow)
All arthropods must do what to grow - Answers - moult
Moult - Answers - shedding of exoskeleton regulated by hormones
4 steps of moulting - Answers - 1. Apolysis
2. Break down of endocuticle layer
3. New cuticle formed
4. Ecydisis
Apolysis - Answers - the separation of the old cuticle from the underlying epidermal cells
Apolysis is stimulated by what - Answers - ecdysteroid moulting hormones release from
prothoracic glands
Apolysis creates a new space under the old cuticle for what - Answers - for the flow of
digestive fluids
What breaksdown the endocuticle layer of the exoskeleton into metabolites - Answers -
the enzymes in the digestive fluid becoming activated
, How is the new cuticle formed - Answers - metabolites are reabsorbed by the epidermal
cells and used to form it
Ecdysis - Answers - the old cuticle is cast off
New cuticle after moulting will be what - Answers - pale and soft
What does the arthropod do to make their bodies bigger before the new cuticle hardens
- Answers - they contract muscles to increase internal fluid pressures
The new body size can be even more increased if the arthropod does what - Answers -
swallows air or water to inflate the gut
Arthropods are extremely vulnerable to what before the new exoskeleton hardens -
Answers - predation and dessication
First arthropods appeared when - Answers - during the cambrian period (>520 mya)
Who were the most successful ancient arthropods - Answers - trilobites
Trilobites survived until when - Answers - the end of the permian period
Trilobites - Answers - arthropods with spiny exoskeletons likely used for defence
Trilobites lived where - Answers - solely in marine environments
Earliest land animals were what - Answers - arthropods
Land arthropods were in what period - Answers - silurian period (440-420 mya)
What kept the earlier land arthropods from drying out - Answers - their exoskeleton
Spiders and dragonflies came in what period - Answers - carboniferous (300 mya)
Ants came in what period - Answers - cretaceous (140 mya)
Bees came from what period - Answers - paleogene (34 mya)
Phylogeny - Answers - evolutionary history of related organisms
Taxonomy - Answers - used to define, name, and group biological organisms
8 groups of taxonomy - Answers - 1. Domain
2. Kingdom
3. Phylum
4. Class
ANSWERS
Insect represent what percent of all known species - Answers - over 50%
Vertebrates - Answers - have an internal skeleton (endoskeleton) with vertebrae
arranged into a spinal column
Invertebrates - Answers - no vertebrae (no internal support structure) they have support
outside their body (exoskeleton)
Two functions of the vertebral column - Answers - 1. Provides support against gravity
2. Allows for large body sizes
Vertebrate animals (5) - Answers - 1. Amphibians
2. Fish
3. Reptiles
4. Birds
5. Mammals
More than 90% of all species are what - Answers - invertebrates
Most recognized species of invertebrates - Answers - arthropods
Arthron - Answers - joint
Podos - Answers - feet
Arthropod means what - Answers - jointed appendages
Two functions of jointed appendages - Answers - 1. Locomotion
2. Modified for different structures (antennae, mouth parts, reproductive structures)
How many known species of arthropods are there - Answers - about 1.2 million
Arthropods include what groups (6) - Answers - 1. Crabs
2. Lobsters
3. Spiders
4. Scorpion
5. Millipedes
6. Centipedes
7. Insects
5 characteristics of arthropods - Answers - 1. Bilateral symmetry
,2. Segmented bodies
3. Ventral nerve cords
4. Dorsal blood vessels
5. Exoskeletons
Bilateral symmetry - Answers - split along the anterior-posterior axis (forming a single
plane of symmetry, separating into left and right sides)
Jellyfish almost have perfect of what type of symmetry - Answers - radial
3 main body axis - Answers - 1. Dorsal/ventral
2. Anterior/posterior
3. Lateral
Dorsal ventral axis - Answers - from top to bottom
Anterior posterior axis - Answers - from front to back
Lateral axis - Answers - from one side to another
Segmented body - Answers - fused into regions/tagmata with different biological
functions
Ventral nerve cord of arthropods is not enclosed in what - Answers - a protective spinal
column
What type of nerve cord do humans have - Answers - dorsal
What kind of circulatory system do humans have - Answers - closed
Open circulatory system of arthropods - Answers - don't have a network of blood
vessels, they have a single dorsal blood vessel with large openings at either end
In arthropods, tissues are directly exposed to what - Answers - blood
Exoskeleton two features - Answers - hard and flexible
Exoskeleton of arthropods is made up of what - Answers - cuticle and epidermis
Exoskeleton cuticle is made up of which two things - Answers - chitin and protein
3 layers of the exoskeleton cuticle - Answers - 1. Waxy epicuticle
2. Exocuticle
3. Endocuticle
Exocuticle is hardened by what - Answers - tanning
,Endocuticle features - Answers - unhardened and stretchy
Epidermis of exoskeleton lies where - Answers - below the endocuticle
Basement membrane of exoskeleton - Answers - thin tissue under epidermis
(separating it form the body cavity)
5 functions of the exoskeleton of arthropods - Answers - 1. Protects from damage
2. Reduces water loss
3. Site for muscle attachment
4. Barrier against microorganisms
5. Supports internal organs
Which part of the exoskeleton reduces water loss - Answers - the epicuticle
Which part of the exoskeleton acts as a barrier against microorganisms - Answers -
epicuticle
Tanning in exoskeleton - Answers - a crosslinking of proteins in the chitin protein matrix
(sclerotization)
Tanning in exoskeleton can be achieved how - Answers - by mineralization
Disadvantage of exoskeleton - Answers - limits growth (so they must moult to grow)
All arthropods must do what to grow - Answers - moult
Moult - Answers - shedding of exoskeleton regulated by hormones
4 steps of moulting - Answers - 1. Apolysis
2. Break down of endocuticle layer
3. New cuticle formed
4. Ecydisis
Apolysis - Answers - the separation of the old cuticle from the underlying epidermal cells
Apolysis is stimulated by what - Answers - ecdysteroid moulting hormones release from
prothoracic glands
Apolysis creates a new space under the old cuticle for what - Answers - for the flow of
digestive fluids
What breaksdown the endocuticle layer of the exoskeleton into metabolites - Answers -
the enzymes in the digestive fluid becoming activated
, How is the new cuticle formed - Answers - metabolites are reabsorbed by the epidermal
cells and used to form it
Ecdysis - Answers - the old cuticle is cast off
New cuticle after moulting will be what - Answers - pale and soft
What does the arthropod do to make their bodies bigger before the new cuticle hardens
- Answers - they contract muscles to increase internal fluid pressures
The new body size can be even more increased if the arthropod does what - Answers -
swallows air or water to inflate the gut
Arthropods are extremely vulnerable to what before the new exoskeleton hardens -
Answers - predation and dessication
First arthropods appeared when - Answers - during the cambrian period (>520 mya)
Who were the most successful ancient arthropods - Answers - trilobites
Trilobites survived until when - Answers - the end of the permian period
Trilobites - Answers - arthropods with spiny exoskeletons likely used for defence
Trilobites lived where - Answers - solely in marine environments
Earliest land animals were what - Answers - arthropods
Land arthropods were in what period - Answers - silurian period (440-420 mya)
What kept the earlier land arthropods from drying out - Answers - their exoskeleton
Spiders and dragonflies came in what period - Answers - carboniferous (300 mya)
Ants came in what period - Answers - cretaceous (140 mya)
Bees came from what period - Answers - paleogene (34 mya)
Phylogeny - Answers - evolutionary history of related organisms
Taxonomy - Answers - used to define, name, and group biological organisms
8 groups of taxonomy - Answers - 1. Domain
2. Kingdom
3. Phylum
4. Class
