Biology 1407 Exam test questions
and answers graded A+
Cleavage - ANS✅✅a series of mitotic divisions with cell growth where the zygote does not enlarge
Blastula - ANS✅✅during cleavage, most animal zygotes form into a ball of cells with a hollow
center
Blastocoel - ANS✅✅hollow center
Gastrulation - ANS✅✅one end of blastula infolds to form many of the layers that will become
organs and appendages
Gastrula - ANS✅✅an embryo at the stage following the blastula, when it is a hollow cup-shaped
structure having three layers of cells
Larval Stage - ANS✅✅Sexually immature form of an animal that is morphologically distinct from
adult, usually eats different food, and often lives in a different habitat from the adult
Metamorphosis - ANS✅✅a developmental transformation that turns an animal into a juvenile that
resembles the adult but is not yet sexually mature
Eudiacaran Fauna - ANS✅✅all members of a soft-bodied, multicellular group of eukaryotes
Cambrian Explosion - ANS✅✅major wave of diversification during Cambrian period of Paleozoic
Body Plans - ANS✅✅particular set of morphological and developmental traits, integrated into a
functional whole...a living organism
Radial Symmetry - ANS✅✅body lacks a front, back, left side, or right side and can be divided into
mirror images when cut through any plane through its central axis
,Bilateral Symmetry - ANS✅✅body has a central longitudinal plane through which the body can be
divided into mirror images; body has front, back, left, and right sides
Asymmetry - ANS✅✅body lacks any symmetry or plane through which body can be divided into
mirror images
Cephalization - ANS✅✅bilateral organisms tend to have a concentration of sensory equipment
and nervous tissue at the anterior end of body
Tissues - ANS✅✅Collection of specialized cells isolated from other tissues by membranes
Ectoderm - ANS✅✅covers surface of embryo, gives rise to outer covering of animal and, in some
animals, the central nervous system
Endoderm - ANS✅✅innermost germ layer that lines pouch formed during gastrulation and gives
rise to digestive tract and other organs (liver, lungs)
Diploblastid - ANS✅✅animals with only these two tissues
Triploblastid - ANS✅✅bilateral animals with a third tissue
Mesoderm - ANS✅✅the third tissue in bilateral animals that fills space between ectoderm and
endoderm
Coelom - ANS✅✅a space, or body cavity, between the digestive tract and the outer body wall
Coelomates - ANS✅✅a "true" coelom forms from the mesoderm tissue layer that lines the
ectoderm and endoderm and connects through the coelom to suspend internal organs
Pseudocoelmates - ANS✅✅tome triploblasts have coelom formed from mesoderm and endoderm
that is disconnected from the digestive cavity
Acoelomates - ANS✅✅third group of triploblasts lack coelom and mesoderm forms continuous
mass of tissue between ectoderm and endoderm
, Spiral Cleavage - ANS✅✅protosomes undergo this process in which the planes of cell division are
diagonal to vertical axis of the embryo
Radial Cleavage - ANS✅✅dueterosomes undergo this process in which planes of cell division are
either parallel to or perpendicular to the vertical axis
Invertebrates - ANS✅✅animals that lack a backbone
Basal - ANS✅✅forming or belonging to a bottom layer or base
Sessile - ANS✅✅attached to substrate; not free-living
Suspension Feeders - ANS✅✅capture food suspended in water passing through body
Sequential Hermaphrodites - ANS✅✅individuals able to make both sex gametes; not at same time
Choanocytes - ANS✅✅flagellated cells that create microcurrent to suck food particles into
fingerlike projections forming a collar around the cell; engulf food via phagocytosis
Amoebocytes - ANS✅✅majority of cellular structure; use pseudopodia to move throughout
mesohyl
Mesohl - ANS✅✅gelatinous matrix layered into sponge "body"
Medusa - ANS✅✅free-swimming with opening to digestive opening oriented downward
Polyp - ANS✅✅sessile, cylindrical forms that adhere to a substrate; digestive opening oriented
upward
Gastrovascular Cavity - ANS✅✅sac with central digestive cavity (gastrovascular cavity) with a
single opening functioning as both mouth and anus
and answers graded A+
Cleavage - ANS✅✅a series of mitotic divisions with cell growth where the zygote does not enlarge
Blastula - ANS✅✅during cleavage, most animal zygotes form into a ball of cells with a hollow
center
Blastocoel - ANS✅✅hollow center
Gastrulation - ANS✅✅one end of blastula infolds to form many of the layers that will become
organs and appendages
Gastrula - ANS✅✅an embryo at the stage following the blastula, when it is a hollow cup-shaped
structure having three layers of cells
Larval Stage - ANS✅✅Sexually immature form of an animal that is morphologically distinct from
adult, usually eats different food, and often lives in a different habitat from the adult
Metamorphosis - ANS✅✅a developmental transformation that turns an animal into a juvenile that
resembles the adult but is not yet sexually mature
Eudiacaran Fauna - ANS✅✅all members of a soft-bodied, multicellular group of eukaryotes
Cambrian Explosion - ANS✅✅major wave of diversification during Cambrian period of Paleozoic
Body Plans - ANS✅✅particular set of morphological and developmental traits, integrated into a
functional whole...a living organism
Radial Symmetry - ANS✅✅body lacks a front, back, left side, or right side and can be divided into
mirror images when cut through any plane through its central axis
,Bilateral Symmetry - ANS✅✅body has a central longitudinal plane through which the body can be
divided into mirror images; body has front, back, left, and right sides
Asymmetry - ANS✅✅body lacks any symmetry or plane through which body can be divided into
mirror images
Cephalization - ANS✅✅bilateral organisms tend to have a concentration of sensory equipment
and nervous tissue at the anterior end of body
Tissues - ANS✅✅Collection of specialized cells isolated from other tissues by membranes
Ectoderm - ANS✅✅covers surface of embryo, gives rise to outer covering of animal and, in some
animals, the central nervous system
Endoderm - ANS✅✅innermost germ layer that lines pouch formed during gastrulation and gives
rise to digestive tract and other organs (liver, lungs)
Diploblastid - ANS✅✅animals with only these two tissues
Triploblastid - ANS✅✅bilateral animals with a third tissue
Mesoderm - ANS✅✅the third tissue in bilateral animals that fills space between ectoderm and
endoderm
Coelom - ANS✅✅a space, or body cavity, between the digestive tract and the outer body wall
Coelomates - ANS✅✅a "true" coelom forms from the mesoderm tissue layer that lines the
ectoderm and endoderm and connects through the coelom to suspend internal organs
Pseudocoelmates - ANS✅✅tome triploblasts have coelom formed from mesoderm and endoderm
that is disconnected from the digestive cavity
Acoelomates - ANS✅✅third group of triploblasts lack coelom and mesoderm forms continuous
mass of tissue between ectoderm and endoderm
, Spiral Cleavage - ANS✅✅protosomes undergo this process in which the planes of cell division are
diagonal to vertical axis of the embryo
Radial Cleavage - ANS✅✅dueterosomes undergo this process in which planes of cell division are
either parallel to or perpendicular to the vertical axis
Invertebrates - ANS✅✅animals that lack a backbone
Basal - ANS✅✅forming or belonging to a bottom layer or base
Sessile - ANS✅✅attached to substrate; not free-living
Suspension Feeders - ANS✅✅capture food suspended in water passing through body
Sequential Hermaphrodites - ANS✅✅individuals able to make both sex gametes; not at same time
Choanocytes - ANS✅✅flagellated cells that create microcurrent to suck food particles into
fingerlike projections forming a collar around the cell; engulf food via phagocytosis
Amoebocytes - ANS✅✅majority of cellular structure; use pseudopodia to move throughout
mesohyl
Mesohl - ANS✅✅gelatinous matrix layered into sponge "body"
Medusa - ANS✅✅free-swimming with opening to digestive opening oriented downward
Polyp - ANS✅✅sessile, cylindrical forms that adhere to a substrate; digestive opening oriented
upward
Gastrovascular Cavity - ANS✅✅sac with central digestive cavity (gastrovascular cavity) with a
single opening functioning as both mouth and anus
