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bio test 2 Flashcards

1
Q

Define life history in biology

A

describes the series of events over its lifetime, such as how resources are allocated for growth,
maintenance, and reproduction. Life history traits affect the life table of an organism. A species’ life history is genetically determined and shaped by the environment and natural selection.

Life history includes growth, reproduction, and survival strategies.

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2
Q

What is a blastopore?

A

The opening that forms during the early development of an embryo

It can develop into the mouth or anus, depending on the organism.

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3
Q

Define mesoderm

A

the middle germ layer in triploblastic organisms (those with three germ layers: ectoderm, mesoderm, and endoderm). It forms during embryonic development and gives rise to various structuresWhen the primitive gut forms, the opening that first connects the gut cavity to the outside of the embryo is called the blastopore

It gives rise to muscles, bones, and the circulatory system.

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4
Q

What is multicellularity?

A

The condition of being composed of multiple cells

Enables specialization of cells for different functions.

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5
Q

What is the archenteron?

A

The primitive gut formed during gastrulation

It eventually develops into the digestive tract.

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6
Q

Define spiral cleavage

A

A type of embryonic development where cells divide at angles to one another

Common in protostomes.

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7
Q

What is indeterminate cleavage?

A

A type of cleavage where the fate of the cells is not determined early

Allows for the potential to form identical twins.

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8
Q

Define bilateral symmetry

A

A body plan in which the left and right sides are mirror images

Facilitates streamlined movement.

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9
Q

What is a deuterostome?

A

An animal whose blastopore develops into the anus

Includes echinoderms and chordates.

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10
Q

Define Lophotrochozoa

A

A clade of animals characterized by a lophophore or trochophore larva

is a Major Clade (Protostomia): A large group of protostome animals.

Key Features:

Lophophore: Ciliated feeding structure.

Trochophore Larva: Planktonic larval stage with cilia.

Includes mollusks and annelids.

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11
Q

What is Arthropoda?

A

A phylum of invertebrate animals with exoskeletons, segmented bodies, and jointed appendages

Includes insects, arachnids, and crustaceans.

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12
Q

Define vertebral column

A

The series of vertebrae forming the backbone

Provides structural support and protects the spinal cord.

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13
Q

What are pharyngeal arches?

A

Structures that form in the embryonic development of vertebrates

They give rise to various structures, including gills and jaws.

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14
Q

Define radial symmetry

A

A body plan in which body parts are arranged around a central axis

Common in organisms like jellyfish.

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15
Q

What is a cuticle?

A

A protective layer covering the outer surface of some organisms

Helps prevent desiccation in terrestrial environments.

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16
Q

Define Ecdysozoa

A

A clade of animals that undergo ecdysis, or molting

Includes arthropods and nematodes.

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17
Q

What is Echinodermata?

A

A phylum of marine animals characterized by a water vascular system and radial symmetry

Includes starfish and sea urchins.

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18
Q

Define notochord

A

A flexible rod-like structure that provides support in embryonic development

It is a key characteristic of chordates.

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19
Q

What is a post-anal tail?

A

An extension of the body past the anus

Present in many chordates during some stage of development.

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20
Q

Define fins with internal support

A

Fins that contain bony or cartilaginous structures for support

Critical for maneuverability in aquatic environments.

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21
Q

What are contractile proteins?

A

Proteins that enable muscle contraction and movement

Essential for mobility in animals.

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22
Q

What is a blastula?

A

An early stage of embryonic development characterized by a hollow ball of cells

Precedes the formation of the gastrula.

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23
Q

Define germ layers

A

The three primary layers of cells in an embryo: ectoderm, mesoderm, endoderm

Each layer develops into different tissues and organs.

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24
Q

What is radial cleavage?

A

A type of cleavage where cells divide symmetrically around the axis

Common in deuterostomes.

25
Define body plan
The overall structure and arrangement of an organism's body parts ## Footnote Influences function and ecological role.
26
What are true tissues?
Groups of similar cells that perform a specific function ## Footnote Key characteristic of complex multicellular organisms.
27
What is an appendage?
A limb or other body part that extends from the body ## Footnote Examples include legs, arms, and fins.
28
Define cranium
The skull that encases and protects the brain ## Footnote A key feature of vertebrates.
29
What is an ossified skeleton?
A skeleton that is composed of bone rather than cartilage ## Footnote Provides greater support and protection.
30
What is a swim bladder?
An internal gas-filled organ that helps fish maintain buoyancy ## Footnote Allows for energy-efficient movement in water.
31
What is gastrula?
An early embryonic stage following the blastula ## Footnote Characterized by the formation of germ layers.
32
Define ectoderm
The outermost germ layer in the embryo ## Footnote Develops into skin and nervous system.
33
What is endoderm?
The innermost germ layer in the embryo ## Footnote Forms the lining of the digestive tract and other organs.
34
What is determinate cleavage?
A type of cleavage where the fate of the cells is determined early ## Footnote Typical of protostomes.
35
Define triploblastic
Organisms that develop three germ layers: ectoderm, mesoderm, endoderm ## Footnote Found in most animal phyla.
36
What is ecdysis?
The process of shedding the outer layer or exoskeleton ## Footnote Common in arthropods and some other invertebrates.
37
Define cephalization
The concentration of sensory and neural organs at the anterior end (head) of an organism ## Footnote Associated with a more active lifestyle.
38
What is a protostome?
An animal whose blastopore develops into the mouth ## Footnote Includes mollusks and annelids.
39
What is Opisthokonta?
A clade that includes animals and fungi ## Footnote Characterized by a single posterior flagellum in the motile cells.
40
Define Chordata
The phylum that includes all animals with a notochord, dorsal nerve cord, and pharyngeal slits ## Footnote Includes vertebrates and some invertebrates.
41
What is Nematoda?
A phylum of roundworms, characterized by a long, cylindrical body ## Footnote Many are parasitic.
42
What is a tetrapod?
A vertebrate animal with four limbs ## Footnote Includes amphibians, reptiles, birds, and mammals.
43
Define endostyle
A ciliated groove in the pharynx of some chordates ## Footnote Involved in filter feeding and iodine absorption.
44
What is a jaw?
A bony or cartilaginous structure in the mouth used for grasping and chewing food ## Footnote A key evolutionary adaptation in vertebrates.
45
Define nerve cord
A bundle of nerve fibers running along the back of an organism ## Footnote Key component of the central nervous system in chordates.
46
What is an operculum?
A bony flap that covers the gills in fish ## Footnote Helps in respiration by creating a pressure difference.
47
What are paired fins?
Fins that come in pairs, located on either side of an organism's body ## Footnote Provide stability and control in aquatic environments.
48
What is the adaptive significance of animal synapomorphies?
Features that enhance survival and reproduction ## Footnote Examples include multicellularity, bilateral symmetry, and segmentation.
49
What can be inferred from a cladogram?
The evolutionary relationships and characteristics of organisms ## Footnote Helps in understanding shared traits among species.
50
What are the five Chordate synapomorphies?
Notochord, pharyngeal slits, post-anal tail, vertebrae, dorsal hollow nerve cord ## Footnote Each contributes to the body plan of efficient hunters.
51
What are two species-rich taxa in aquatic vertebrates?
Actinopterygii (ray-finned fishes) and Amphibia (frogs and salamanders) ## Footnote These groups exhibit diverse ecological roles.
52
List the evolutionary origins of these characteristics: cephalization, diploblasty, multicellularity, triploblasty
Multicellularity: Originated around 1 billion years ago in various lineages (e.g., plants, fungi, animals). Diploblasty: Evolved around 700 million years ago in simple organisms like cnidarians) and ctenophores (two germ layers: ectoderm and endoderm). Triploblasty: Appeared around 600 million years ago in more complex animals (three germ layers: ectoderm, endoderm, mesoderm). clade bilateria Cephalization: Emerged around 550 million years ago in bilaterally symmetrical animals, leading to the development of a head with sensory organs and a centralized nervous system clade bilateria ## Footnote Indicates the sequence of evolutionary developments.
53
Rank the following clades from most inclusive to least inclusive: mollusca, bilateria, lophotrochozoan, protostomia.
* Bilateria * Protostomia * Lophotrochozoa * Mollusca ## Footnote Reflects the hierarchy of biological classification.
54
What are the adaptive significances of animal body plan characteristics?
* Tissues * Bilateral symmetry * Triploblasty * Presence of a coelom * Appendages * Cephalization ## Footnote Each trait offers advantages in survival and reproduction.
55
How do Chordate synapomorphies aid in hunting?
They provide structural and functional advantages for predation ## Footnote Features like the jaws and nerve cord enhance hunting efficiency.
56
Why is it important to distinguish among different animal groups?
To avoid negative consequences in ecology and conservation ## Footnote Examples include mismanagement of species and loss of biodiversity.
57
Describe two ecological roles for invertebrates.
* Pollinators * Decomposers ## Footnote Invertebrates play vital roles in ecosystems.
58
How can evolutionary relationships inform ecology and conservation?
They help predict species interactions and ecosystem dynamics ## Footnote Understanding relationships can guide conservation efforts and biodiversity maintenance.

bio 120 (2 decks)

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