Theory Test 2 L7-L13

What distinguishes animals from plants?

Animals are heterotrophic (they consume organic material), while plants are autotrophic (they produce their own food).

Define 'Invertebrates'.

Invertebrates are animals without a backbone, making up about 95% of the animal kingdom.

What is the significance of the germ layers in animal development?

Germ layers (ectoderm, endoderm, mesoderm) are essential in forming specialized tissues and organs during embryonic development.

What defines 'Protostomes' in animal development?

In protostomes, the blastopore develops into the mouth first, followed by the anus.

What defines 'Deuterostomes' in animal development?

In deuterostomes, the blastopore becomes the anus first, with the mouth forming later.

What is the importance of the Cambrian explosion?

It was a period of rapid diversification of animal phyla, leading to the emergence of many complex forms of life.

What dominates the animal kingdom in terms of species diversity?

Invertebrates dominate, accounting for about 95% of known animal species.

What are the three types of body cavities in animals?

Coelomates (true coelom), pseudocoelomates (pseudocoel), and acoelomates (no body cavity).

What is the reproductive strategy of most animals?

Most animals reproduce sexually, involving the fertilization of eggs by sperm.

What role do echinoderms play in animal evolution?

Echinoderms are classified as deuterostomes and provide insight into the evolutionary lineage of vertebrates.

Define 'Cephalization' in the context of animal evolution.

Cephalization is the development of a concentrated sensory and nerve center (head) in bilaterally symmetrical animals.

How are animals categorized based on tissue layers?

Animals are categorized as diploblastic (two layers) or triploblastic (three layers).

What distinguishes the phylum Porifera (sponges)?

Porifera are characterized by their porous bodies, lack of true tissues, and unique feeding mechanisms.

What is the role of choanocytes in sponges?

Choanocytes are specialized cells that create water currents to filter food particles from the water.

How do cnidarians capture prey?

Cnidarians use specialized cells called cnidocytes, which contain nematocysts that inject toxins into their prey.

What is the general body plan of a cnidarian?

Cnidarians have a simple body plan with a gastrovascular cavity, serving both digestion and circulation.

What adaptations do arthropods have for survival on land?

Arthropods have a waxy cuticle to prevent desiccation, specialized respiratory structures, and strong appendages for movement.

What is the primary excretory system in arthropods?

Arthropods utilize Malpighian tubules for waste removal, which helps maintain internal homeostasis.

What defines the class Insecta within arthropods?

Insects are characterized by their three-part body structure, jointed appendages, and their vast diversity in forms and functions.

What is the metamorphosis lifecycle in insects?

Insects undergo either incomplete (hemimetabolous) or complete (holometabolous) metamorphosis, resulting in different life stages.

What are myriapods, and how do they differ from other arthropods?

Myriapods are characterized by their numerous body segments and jointed appendages, generally bearing one or two pairs of legs per segment.

What ecological roles do myriapods play?

Myriapods contribute to nutrient cycling and decomposition processes in soil ecosystems.

What are the two subclasses of the class Clitellata?

The two subclasses are Hyrudinea (leeches) and Oligochaeta (earthworms).

Describe the importance of molluscs in ecosystems.

Molluscs serve as key food sources in many food webs, provide ecosystem services like bioturbation, and are important to fisheries.

Evolutionary relationship

Echinoderms are classified as deuterostomes and are closely related to chordates, sharing a common ancestor and exhibiting key developmental similarities.

What are the key characteristics of echinoderms?

Echinoderms exhibit radial symmetry, a calcareous endoskeleton, tube feet, and a water vascular system.

What animals are included in the phylum Echinodermata?

Echinodermata includes sea stars, sea urchins, sand dollars, and sea cucumbers.

How do echinoderms move?

Echinoderms move using tube feet, which are powered by their water vascular system.

What is regeneration in echinoderms?

Echinoderms have the ability to regenerate lost body parts, including arms and internal organs.

What is the feeding strategy of echinoderms?

Many echinoderms are predators or scavengers, using their tube feet to pry open shells and access food.

Describe the reproductive methods of echinoderms.

Echinoderms can reproduce both sexually and asexually; sexual reproduction often involves external fertilization in the water.

What unique feature distinguishes echinoderm larvae?

Echinoderm larvae typically exhibit bilateral symmetry, which changes to radial symmetry as they mature.

What role do echinoderms play in marine ecosystems?

Echinoderms are key players in marine food webs and help maintain coral reef health through their feeding and sediment disturbance.

How do echinoderms respire?

Echinoderms respire through tube feet and specialized structures like papulae, which help them exchange gases.

Echinoderms

Bilateral symmetry in large

What type of symmetry do adult echinoderms exhibit?

Adult echinoderms exhibit radial symmetry.

What type of skeleton do echinoderms possess?

Echinoderms possess a calcareous endoskeleton.

Which structure in echinoderms aids in locomotion?

Tube feet, powered by a water vascular system, aid in locomotion.

Do echinoderms have a nervous system?

Echinoderms have a simple nervous system without a centralized brain.

How do echinoderms feed?

Echinoderms use their tube feet to pry open prey and often expel their stomach to digest food externally.

What is the role of the water vascular system in echinoderms?

The water vascular system regulates movement and feeding and enables respiration.

Do echinoderms possess a circulatory system?

Echinoderms lack a true circulatory system; nutrients are distributed through coelomic fluid.

What is unique about echinoderm larvae compared to adults?

Echinoderm larvae are typically bilaterally symmetrical, unlike the radial symmetry of adults.

How do echinoderms defend themselves?

Many echinoderms can expel toxic substances or utilize their spiny skin as a defense mechanism.

What is the ecological role of echinoderms in marine environments?

Echinoderms play key roles as predators, prey, and contributors to the health of marine ecosystems.

Percentages of all animals are eukarya

78%

How many animal species are catalogued

EST 12

How many are invertebrates

EST 95

How many extant

1

How many extinct

99

Ediacara biota

565 may

Cambrian explosion

542- 251

Vertebrates

365

What is a animal

Multiticellular

What is an animal

Multicellular, heterotopic, eukaryotic and tissues develop from embryonic layers

What are the three primary germ layers?

The three primary germ layers are ectoderm, mesoderm, and endoderm.

What does the ectoderm develop into?

The ectoderm develops into the skin, nervous system, and sensory organs.

What organs and systems are formed from the mesoderm?

The mesoderm gives rise to muscles, bones, circulatory system, and reproductive organs.

What does the endoderm form?

The endoderm forms the lining of the digestive and respiratory tracts, as well as glandular organs.

What is the significance of germ layers in development?

Germ layers are essential for the formation of differentiated tissues and organs during embryonic development.

What type of organisms are considered diploblastic?

Diploblastic organisms have two germ layers: ectoderm and endoderm (e.g., cnidarians).

What are triploblastic organisms?

Triploblastic organisms have three germ layers: ectoderm, mesoderm, and endoderm (e.g., most animals).

How do germ layers influence body plan?

Germ layers determine the body plan and organizational structure of an organism, influencing its development.

What role do stem cells play in germ layer formation?

Stem cells differentiate into various cell types that compose each germ layer, crucial for tissue development.

What is the process of gastrulation?

Gastrulation is the process during embryonic development where the single-layered blastula reorganizes into the three germ layers.

What are the main types of symmetry found in animals?

The main types of symmetry in animals are bilateral symmetry, radial symmetry, and asymmetry.

Define bilateral symmetry in animals.

Bilateral symmetry is a type of symmetry where the body can be divided into two mirror-image halves along a single plane.

Give an example of an animal with bilateral symmetry.

Examples of animals with bilateral symmetry include humans, cats, and butterflies.

Define radial symmetry in animals.

Radial symmetry is a type of symmetry where the body can be divided into similar halves around a central axis.

Give an example of an animal with radial symmetry.

Examples of animals with radial symmetry include jellyfish, sea anemones, and starfish.

What is asymmetry in animals?

Asymmetry refers to a lack of symmetry in an organism's body structure, meaning it cannot be divided into similar halves.

Give an example of an asymmetrical animal.

Examples of asymmetrical animals include sponges and some species of corals.

What evolutionary advantage does bilateral symmetry provide?

Bilateral symmetry allows for streamlined movement and the development of a centralized nervous system.

How does radial symmetry benefit certain animals?

Radial symmetry allows for equal access to the environment from all sides, beneficial for sessile organisms.

What type of symmetry do most animals exhibit?

Most animals exhibit bilateral symmetry, which is more common in mobile organisms.

What is tissue development in animals?

Tissue development refers to the process by which cells differentiate and form various types of tissues during embryonic development.

What are the four primary types of animal tissues?

The four primary types of animal tissues are epithelial, connective, muscle, and nervous tissue.

What role does stem cell differentiation play in tissue development?

Stem cell differentiation is crucial for tissue development as stem cells give rise to specialized cells that form different tissues.

How does the ectoderm contribute to tissue development?

The ectoderm gives rise to epithelial tissues, nervous tissue, and parts of the skin.

What tissues are derived from the mesoderm?

The mesoderm develops into muscle tissue, connective tissue, and the circulatory and excretory systems.

What is the contribution of the endoderm in tissue development?

The endoderm forms epithelial tissues lining the digestive and respiratory tracts and glandular organs.

What factors influence the differentiation of stem cells into specific tissues?

Factors influencing stem cell differentiation include signaling molecules, gene expression, and the cellular environment.

What is the significance of tissue regeneration in animals?

Tissue regeneration is important for healing and recovery from injuries and is seen in various organisms like starfish and salamanders.

How do growth factors affect tissue development?

Growth factors are proteins that stimulate cell growth, proliferation, and differentiation, playing a key role in tissue development.

What is the role of epithelial tissue in animals?

Epithelial tissue serves as protective layers, facilitates absorption, secretion, and sensation, and forms membranes and glands.

What does the ectoderm develop into?

The ectoderm develops into the outer layer of the skin, nervous system, and sensory organs.

What type of tissue is formed from the ectoderm?

The ectoderm forms epithelial tissues and nervous tissues.

What is the role of ectoderm in the nervous system?

The ectoderm gives rise to neural tissues, including the brain and spinal cord.

How does ectoderm contribute to sensory structures?

The ectoderm differentiates to form sensory organs, including eyes and ears.

What are neural crest cells?

Neural crest cells are ectoderm-derived cells that migrate to form various tissues, including peripheral nerves and pigment cells.

What happens if ectodermal development is disrupted?

Disruptions can lead to defects in skin, nervous system, and sensory organs, resulting in various congenital disorders.

What embryonic process forms the ectoderm?

The ectoderm is formed during the process of gastrulation.

What is the significance of ectodermal tissue?

Ectodermal tissue is essential for protection, sensory perception, and communication with the environment.

What other structures do ectodermal cells form besides skin and nerves?

Ectodermal cells contribute to hair, nails, and melanocytes (pigment cells).

What role does ectoderm play in the formation of glands?

The ectoderm develops into glands such as sweat glands and mammary glands.

What is the endoderm?

The endoderm is the innermost germ layer in embryonic development that gives rise to various internal structures.

What organs develop from the endoderm?

The endoderm develops into the lining of the digestive tract, respiratory tract, and organs such as the liver and pancreas.

What type of tissues are derived from the endoderm?

The endoderm gives rise to epithelial tissues that line internal organs and glands.

How does the endoderm contribute to the respiratory system?

The endoderm forms the epithelial lining of the trachea, bronchi, and alveoli in the lungs.

What function do endoderm-derived organs serve?

Endoderm-derived organs are crucial for digestion, respiration, and metabolic functions.