BISC 162 Exam Questions and answers with complete solutions Latest Updated 2025
| Verified
* Animal Origins & the Evolution of Body Parts chpt. 31 -
What are the characteristics of animals ? - - multicellular
- Heterotrophic
-Internal digestions
-movement
What is the definition of Heterotrophic ? - -- cannot manufacture its own food ---- >
instead obtains its food and energy by taking in organic substances, usually plant or
animal matter. **All animals, protozoans, fungi, and most bacteria are heterotrophs
What are some traits that are animal synapomorphies ? - - Genetic traits
- Morphological traits
What are Morphological traits ? - The size, shape, and structure of an organism or one
of its parts. Biologists usually describe the morphology of an organism separately from
its physiology.
What type of junctions do animals have ? - Intracellular junctions
How can you describe animals? - - Monophyletic
-Diverse
What is the definition of Monophyletic ? - (of a group of organisms) descended from a
common evolutionary ancestor or ancestral group, especially one not shared with any
other group.
How many clades are animals made up of ? - Many
What are the different clades of Animals? - - Insects ( biggest clade)
- mammals
- Vertebrates
- Sponges
- Echinoderms
- Cnidaria
- Round Worms
- Mollusks
- Crustaceans
- Other Arthropods
What group is one of the earliest groups of Animals? - Sponges
,What are the characteristics of Sponges? - - Choanocytes, Amoebocytes
- no tissues, spicules
- filter feeding
- Osculum , Osmium , Pore
- Sexual / Asexual Reproduction
What is a Choanocyte? - A process by which they circulate water and collect tiny,
particle-size food from the water. Water enters through ostia (pores) and is moved
through by choanocyte cells which stimulate a water current. The ring of pseudopodia of
the choanocytes traps passing food.
What is an Amoebocyte ? - There are different types of amoebocytes, but they all
appear to be totipotent. They are able to change into other types of amoebocytes or into
pinacocytes or choanocytes. Amoebocytes participate in reproduction and the produce
spicules.
What are Spicules? - provide structure support for the sponge
What is an Osculum ? - a large aperture in a sponge through which water is expelled
What is the Osmium ? - a large opening where water flows OUT of the sponge
What function does the pore of a sponge serve? - where water flows into the sponge
When/ why do sponges use Sexual and Asexual Reproduction? - Asexual reproduction
:
- budding
- production of reduction bodies
- gemmule production
Sexual reproduction:
-sponges are monoecious with nonsynchronous hermaphroditism and are protandrous.
How are animal groups defined? - Developmental patterns
What are the difference steps/points in Animals Development? - - Zygote, Embryo
- Cleavage
- Blastula
- Blastocoel
- Gastrulation
- Gastrula
What is the definition of a Zygote and an Embryo ? - -a diploid cell resulting from the
fusion of two haploid gametes; a fertilized ovum.
, -an unborn or unhatched offspring in the process of development, in particular a human
offspring during the period from approximately the second to the eighth week after
fertilization (after which it is usually termed a fetus).
What is the Cleavage in an Animals development ? - Animal cells undergo something
called cleavage, which is the rapid cell division that leads to a multicellular embryo. You
started this stage as a zygote, or newly fertilized egg, and ended as a blastula, or hollow
cell ball.
What is the Blastula? - an animal embryo at the early stage of development when it is a
hollow ball of cells.
What is a Blastocoel? - the fluid-filled cavity of a blastula
What is gastrulation? - a phase early in the embryonic development of most animals,
during which the single-layered blastula is reorganized into a multilayered structure
known as the gastrula.
What is a gastrula? - an embryo at the stage following the blastula, when it is a hollow
cup-shaped structure having three layers of cells
What types of features define early phylogenetic events? - - Embryonic features
- Developmental features
What are some other features that define early phylogenetic events? - - Symmetry
- Type of body cavity
- Blastopore
- Cleavage
- Tissue Layers
Are Animal's Body plans usually symmetrical? - Yes
What are the different types of symmetry an Animals Body plan can have? - -
Asymmetrical
- Radial Symmetry
- Bilateral Symmetry
What is the definition of Asymmetrical? - having parts that fail to correspond to one
another in shape, size, or arrangement; lacking symmetry
What is the definition of Radial Symmetry ? - symmetry around a central axis, as in a
starfish or a tulip flower
What is the definition of Bilateral Symmetry? - the property of being divisible into
symmetrical halves on either side of a unique plane.
| Verified
* Animal Origins & the Evolution of Body Parts chpt. 31 -
What are the characteristics of animals ? - - multicellular
- Heterotrophic
-Internal digestions
-movement
What is the definition of Heterotrophic ? - -- cannot manufacture its own food ---- >
instead obtains its food and energy by taking in organic substances, usually plant or
animal matter. **All animals, protozoans, fungi, and most bacteria are heterotrophs
What are some traits that are animal synapomorphies ? - - Genetic traits
- Morphological traits
What are Morphological traits ? - The size, shape, and structure of an organism or one
of its parts. Biologists usually describe the morphology of an organism separately from
its physiology.
What type of junctions do animals have ? - Intracellular junctions
How can you describe animals? - - Monophyletic
-Diverse
What is the definition of Monophyletic ? - (of a group of organisms) descended from a
common evolutionary ancestor or ancestral group, especially one not shared with any
other group.
How many clades are animals made up of ? - Many
What are the different clades of Animals? - - Insects ( biggest clade)
- mammals
- Vertebrates
- Sponges
- Echinoderms
- Cnidaria
- Round Worms
- Mollusks
- Crustaceans
- Other Arthropods
What group is one of the earliest groups of Animals? - Sponges
,What are the characteristics of Sponges? - - Choanocytes, Amoebocytes
- no tissues, spicules
- filter feeding
- Osculum , Osmium , Pore
- Sexual / Asexual Reproduction
What is a Choanocyte? - A process by which they circulate water and collect tiny,
particle-size food from the water. Water enters through ostia (pores) and is moved
through by choanocyte cells which stimulate a water current. The ring of pseudopodia of
the choanocytes traps passing food.
What is an Amoebocyte ? - There are different types of amoebocytes, but they all
appear to be totipotent. They are able to change into other types of amoebocytes or into
pinacocytes or choanocytes. Amoebocytes participate in reproduction and the produce
spicules.
What are Spicules? - provide structure support for the sponge
What is an Osculum ? - a large aperture in a sponge through which water is expelled
What is the Osmium ? - a large opening where water flows OUT of the sponge
What function does the pore of a sponge serve? - where water flows into the sponge
When/ why do sponges use Sexual and Asexual Reproduction? - Asexual reproduction
:
- budding
- production of reduction bodies
- gemmule production
Sexual reproduction:
-sponges are monoecious with nonsynchronous hermaphroditism and are protandrous.
How are animal groups defined? - Developmental patterns
What are the difference steps/points in Animals Development? - - Zygote, Embryo
- Cleavage
- Blastula
- Blastocoel
- Gastrulation
- Gastrula
What is the definition of a Zygote and an Embryo ? - -a diploid cell resulting from the
fusion of two haploid gametes; a fertilized ovum.
, -an unborn or unhatched offspring in the process of development, in particular a human
offspring during the period from approximately the second to the eighth week after
fertilization (after which it is usually termed a fetus).
What is the Cleavage in an Animals development ? - Animal cells undergo something
called cleavage, which is the rapid cell division that leads to a multicellular embryo. You
started this stage as a zygote, or newly fertilized egg, and ended as a blastula, or hollow
cell ball.
What is the Blastula? - an animal embryo at the early stage of development when it is a
hollow ball of cells.
What is a Blastocoel? - the fluid-filled cavity of a blastula
What is gastrulation? - a phase early in the embryonic development of most animals,
during which the single-layered blastula is reorganized into a multilayered structure
known as the gastrula.
What is a gastrula? - an embryo at the stage following the blastula, when it is a hollow
cup-shaped structure having three layers of cells
What types of features define early phylogenetic events? - - Embryonic features
- Developmental features
What are some other features that define early phylogenetic events? - - Symmetry
- Type of body cavity
- Blastopore
- Cleavage
- Tissue Layers
Are Animal's Body plans usually symmetrical? - Yes
What are the different types of symmetry an Animals Body plan can have? - -
Asymmetrical
- Radial Symmetry
- Bilateral Symmetry
What is the definition of Asymmetrical? - having parts that fail to correspond to one
another in shape, size, or arrangement; lacking symmetry
What is the definition of Radial Symmetry ? - symmetry around a central axis, as in a
starfish or a tulip flower
What is the definition of Bilateral Symmetry? - the property of being divisible into
symmetrical halves on either side of a unique plane.
