Biology Exam 4

Animals are ____________ they obtain energy and nutrients by eating other organisms

heterotrophs

Animals have _____________, collections of specialized cells that function as a unit.

tissues

Tissues form from layers of ________________

embryonic cells

Animal’s process their food inside their bodies. Many animals have an efficient __________ that has a mouth at one end and an anus at the other

digestive system

The tissues of animals include those composed of unique ________________

nerve and muscle cells

Their nerve and muscle cells enable animals to ________ as well as to _________ and ____________ potential prey

move; capture; detect

Animals differ from both plants and fungi in their mode of ____________

nutrition

Unlike plants, animals cannot construct all of their own __________

organic molecules

Unlike fungi, most animals feed by ______________________

ingesting their food and then using enzymes to digest it within their bodies

Unlike plants and fungi, animals lack the structural support of _________

cell walls

What is able to provide cell membrane structural support in animal cells and connect them to one another

Proteins

What is the most abundant structural proteins found in animal cells

collagen

T or F: collagen in not found in plants or fungi

True

What type of cells are central to the animal lifestyle

muscle and nerve cells

What stage dominates the animals reproductive sexual lifestyle

a. haploid

b. diploid

B

In the haploid stage, _______ and ________ cells are produced directly by _____________

sperm, egg, meiotic division

In most animal species a _________ fertilizes a _________ forming a _______

small, flagellated sperm; larger, nonmotile egg; diploid zygote

After formation the zygote undergoes

cleavage

What is cleavage

a succession of mitotic cell divisions without cell growth during divisions

During the development of most animals, cleavage leads to the formation of a multicellular embryonic stage called a ____________

blastula

What is the structure of a blastula

a hollow ball

Following the formation a blastula is the process of ___________

gastrulation

What occurs during gastrulation

the layers of embryonic tissues that will develop into adult body parts are produced

Before the clevage is formed how many rounds of cell division must the zygote undergo

three round to produce an eight-cell embryo

What is the first step in early embryonic development in animals

the zygote of an animal undergoes a series of mitotic cell divisions called cleavage

What is the second step in early embryonic development in animals

An eight-cell embryo is formed by three rounds of cell division

What is the third step in early embryonic development in animals

The cleavage produces a multicellular stage called a blastula. The blastula is typically a hollow ball of cells that surround a cavity called the blastoceol.

What is the fourth step in early embryonic development in animals

Animals undergo gastrulation, a process in which one end of the embryo fold inward, expands, and eventually fills the blastocoel, producing layers of embryonic tissue: the ectoderm (outer layer) and the endoderm (inner layer)

What is the fifth step in early embryonic development in animals

the pouch formed by gastrulation, called the archenteron, opens to the outside via the blastopore

What is the sixth step in early embryonic development in animals

The endoderm of the archenteron develops into the tissue lining of the animal’s digestive tract

What is the term used to describe a sexually immature form of an animal that is morphologically distinct from the adult, usually eats different food, and may even have a different habitat than the adult

larva

Animal larvae eventually undergo _______________

metamorphosis

What is metamorphosis

a developmental transformation that turns the animal into a juvenile that resembles an adult but is not sexually mature

Many of the regulatory genes of animals contain sets of DNA sequences called _______

homeoboxes

What genes play important roles in the development of animal embryos, controlling the expression of many other genes that influence morpholgy

Hox genes

When did the common ancestor of all extant animal species live

770 millions years ago

What is the protists that is the closest living relatives to animals

choanoflagellates

What is the first line of evidence that choanoflagellates are closely related to animals

morphologically, choanoflagellate cells and the collar cells of sponges, a basal group of animals, are almost indistinguishable

What is the second line of evidence that choanoflagellates are closely related to animals

Similar collar cells have been identified in other animals, including cnidarians, flatworms, and echinoderms

What is the third line of evidence that choanoflagellates are closely related to animals

DNA sequence data indicate that choanoflagellates and animals are sister groups. In addition, genes for signaling and adhesion proteins previously known only from animals have been discovered in choanoflagellates

The origin of multicellularity requires the evolution of new ways for cells to ________ and __________ to each other

adhere and signal

Comparisions of choanoflagellate and animal genomes suggest that key steps in the transition to multicellularity in animals involved _________________________

new ways of using proteins or part of proteins that were encoded by genes found in chanoflagellates

When was the neoproterozoic era

1 billion years ago until 541 million years ago

The first generally accepted macroscopic fossils of animals date from about

560 million years ago

The members of an early group of mostly soft-bodies multicellular eukaryotes is known as

Ediacran biota

Among the oldest Ediacaran fossils that resemble animals, some have been classified as ___________

molluscs

When was the Ediacaran period

from 635 million years ago to 541 million years ago

T or F: the Ediacaran period provides early evidence of ______________

predation

When was the time period for the Paleozoic Era

from 541 million years ago to 252 million years ago

What is the wave of animal diversification during the Paleozoic era called

the Cambrian explosion

What kind of fossils were found during the Cambrian explosion

half of all extant of animal phyla such as the first antrhopods, chordates, and echinoderms

Most of the fossils from the Cambrian explosion are of _________________ clade

bilaterians

What is the bilaterians

an enormous clade whose members typically have a two-sided or bilaterally symmetric form and a complete digestive tract, an efficient digestive system that has a mouth at one end and an anus at the other

What group of animals were the first to adapt to terrestrial habitats

anthropods

When did vertebrates colonize land

around 365 million years ago

What are the 2 terrestrial vertebrates that originally colonized the land that still survive today

the amphibians and the aminotes (reptiles such as birds and mammals)

When was the Mesozoic Era

from 252 million years ago to 66 million years ago

On land during the Mesozoic Era descent with modification in some tetrapods led to the origin of ______________

winds and other flight equipment in pterosaurs and birds

What mammals appeared during the mesozoic era

nocturnal insect-eaters

When was the Cenozoic Era

66 million years ago to the present

What ushered the Cenozoic Era

mass extinctions of both terrestrial and marine animals

What is the term used to describe a particular set of morphological and developmental traits that are integrated into a function whole - the living animal

body plan

A basic feature of animal bodies is their type of ____________ or ____________

symmetry; absence of symmetry

What are the 2 types of symmetry for animal bodies

radial or bilateral

The body parts of a radially symmetrical animal are arranged ________________

around a single main axis that passes through the center of the animal.

The body parts of a bilaterally symmetrical animal are arranged ________________________

around two axes of orientation, the head-tail axis and the dorsal-ventral axis

T or F: the symmetry of an animal does not relate to its lifestyle

False: it fits its lifestyle

Many radial animals are _________ or __________

sessile (living attached to a substrate); planktonic (drifting or weakly swimming)

What type of animals have a bilaterally symmetric body plan

arthropods and mammals

Nearly all animals with a bilaterally symmetric body plan have _____________

sensory equipment concentrated at the head end of their body, including a central nervous system

What is able to enable bilateral animals to coordinate the complex movements involved in crawling, burrowing, flying, or swimming

central nervous system

What layers of tissue form the various tissues and organs of the body

germ layers

What is the germ layer that covers the surface of the embryo

ectoderm

What does the ectoderm give rise to

the outer covering of the animal and in some phyla to the central nervous system

What is the innermost germ layer that lines the pouch that forms during gatrulation called

endoderm

What does the endoderm give rise to

the lining of the digestive tract (or cavity) and to the lining of organs such as the liver and lungs of vertebrates

What are animals that only have ectoderm and endoderm layers called

diploblastic

What are examples of an animal group that are diploblastic

cnidarians

What is the third germ layer that all bilaterally symmetrical animals called

the mesoderm

Where is the mesoderm found

between the ectoderm and the endoderm

Since animals with bilateral symmetry have 3 germ layers they are said to be

triploblastic

In triploblasts what germ layer forms the muscle and most other organs between the digestive tract and the outer covering of the animal

mesoderm

What is the fluid or air-filled space located between the digestive tract (endoderm) and the outer body wall (ectoderm) found in nearly all animals

the body cavity

What are some functions of body cavities

provide structural support and facilitate the internal transport of nutrients, gases, and wastes

What is the body cavity that forms tissue derived from mesoderm found in many triploblastic animals

coelom

The inner and outer layers of mesoderm that surround the coelom cavity connect and form structures that suspend the _________________

internal organs

In soft-bodies animals what is the coelom’s function

the fluid in the coelom acts like a skeleton against which muscles can work and enables the internal organs to grow and move independently of the outer body wall.

What is the body cavity that forms between the mesoderm and endoderm in triploblastic animals

hemocoel

What is the fluid found in a hemocoel that functions in the internal transport of nutrients and waste

hemolymph

What is the structure of animals that lack a body cavity

thin, flat bodies that do not require an internal transport system

What are the 2 developmental modes of animals

protostome development and deuterostome development

What are differences that distinguish protostome and deuterostome development

difference in cleavage, coelom formation, and fate of the blastospore

What type of cleavage do animals with protostome development undergo

spiral clevage

What is spiral cleavage

the planes of cell division are diagonal to the vertical axis of the embryo

The so-called _______________ of some animals with protostome development rigidly determines the developmental fate of embryonic cell very early

determinate cleavage

Deuterostome development is predominantly characterized by what type of cleavage?

radial cleavage

What does a spiral cleavage cell look like

smaller cells are centered over the grooves between larger, underlying cells

What does a radial cleavage cell look like

the tiers of cells are aligned one directly above the other

Most animals with deuterostome development have radial cleavage as well as ______________

indeterminate cleavage

During gastrulation, an embryo’s developing digestive tube initially forms as a blind pouch known as the _____________

archenteron