Biology Chapter 32: Animal Characteristics

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Questions and Answers

Which of the following is NOT a characteristic of animals?

No cell walls

Autotrophic (correct)

Heterotrophic

Multicellular

What defines specialization in cells?

Performing a specific function

What is the term for where similar cells connect to form tissues?

Cell junctions

What do organs consist of?

Similar tissues joining together Signup and view all the answers

What forms an organ system?

Similar organs Signup and view all the answers

What is ingestion?

How animals obtain complex organic molecules by eating food Signup and view all the answers

What happens during digestion?

Organic molecules are extracted from ingested materials Signup and view all the answers

What is a zygote?

The result of two haploid cells coming together, typically with 46 chromosomes Signup and view all the answers

What process does a zygote undergo to form tissues and organs?

Mitotic division Signup and view all the answers

What is differentiation in cells?

Becoming different and specialized Signup and view all the answers

What is the nervous system primarily made up of?

Neurons Signup and view all the answers

What leads to movement in the muscular and nervous systems?

The result of the coordination between these two systems Signup and view all the answers

What are invertebrates characterized by?

Not having a backbone Signup and view all the answers

What do chordates possess at some point in their development?

Notochord, dorsal nerve cord, pharyngeal pouches, postanal tail Signup and view all the answers

What term refers to identical body arrangement on opposite sides of an axis?

Bilateral Symmetry Signup and view all the answers

What does cephalization refer to?

Concentration of brain and sensory structures near the head Signup and view all the answers

What are germ layers?

Tissue layers in embryos Signup and view all the answers

What type of circulatory system do vertebrates have?

Closed circulatory system Signup and view all the answers

What do hermaphrodites do?

Produce both types of gametes for asexual reproduction Signup and view all the answers

What is direct development in vertebrates?

Developing through life with the same body form/structure Signup and view all the answers

What happens during cleavage?

A series of divisions increases the number of cells without growing in size at first Signup and view all the answers

What is the function of the endoderm?

Forms internal organs Signup and view all the answers

What is the mesoderm responsible for?

Forms muscles, skeleton, and circulatory system Signup and view all the answers

Study Notes

Animal Characteristics

Multicellular organisms that are heterotrophic, consuming food rather than producing it.
Lack cell walls, distinguishing them from plants and fungi.
Classified into vertebrates, which possess a backbone, and invertebrates, which do not.
Reproduce sexually, forming a zygote when haploid cells combine.

Cell Structure and Function

Specialization allows cells to perform specific functions.
Cell junctions connect similar cells to form tissues.
Organs arise from the combination of similar tissues, allowing for specific functions.
Organ systems are composed of groups of similar organs working together.

Nutrition and Energy

Ingestion refers to how animals consume complex organic molecules through eating.
Digestion is the extraction of organic molecules from ingested materials.

Developmental Biology

A zygote undergoes mitotic division to develop tissues and organs.
Differentiation transforms mass cells into specialized cells, enabling specific functions.
Embryonic development involves stages including cleavage, blastula formation, and gastrulation to create germ layers.

Nervous and Muscular Systems

The nervous system consists of neurons responsible for conducting electrical signals and processing information.
The muscular system enables movement through muscle contraction stimulated by nerves.

Invertebrate Characteristics

Invertebrates represent the majority of animal species and exhibit various symmetries like radial or bilateral.
Simple forms include sponges, whereas complex forms include arthropods like spiders.
Common body features include segmentation, fluid pressure for support, and varying nervous system complexity.

Chordate Characteristics

Chordates possess a notochord, dorsal nerve cord, pharyngeal pouches, and a postanal tail at some point in development.
The notochord develops into the spinal column, while the dorsal nerve cord forms the brain and spinal cord.
Other structures evolve from the germ layers: endoderm, ectoderm, and mesoderm.

Symmetry and Body Plan

Body plan describes an organism's shape, symmetry, and internal organization, including anatomical orientation (dorsal, ventral).
Cephalization is significant in bilaterally symmetrical animals, concentrating sensory organs near the head.

Support Systems

Invertebrates often rely on an external skeleton or fluid pressure for body support, while vertebrates possess an endoskeleton.
Body coverings, or integument, protect and maintain moisture.

Circulatory and Respiratory Systems

Invertebrates may have open circulatory systems, where blood flows freely, while vertebrates have closed systems with blood contained in vessels.
Gas exchange methods vary: gills for aquatic vertebrates and lungs for terrestrial vertebrates.

Excretory Systems

Invertebrates typically have digestive tracts and excrete waste primarily as ammonia.
Vertebrates have complex excretory systems to filter and remove waste.

Reproductive Strategies

Reproduction can occur via asexual means in hermaphrodites or through direct and indirect development stages.
Fertilization methods vary: external in aquatic species and internal in many terrestrial species.

Cell Types and Division

Sperm and egg cells contain a haploid number of chromosomes; sperm are motile while eggs provide nourishment during early development.
Cleavage increases cell quantity without size growth initially, leading to the hollow blastula stage.
Gastrulation results in a multilayered embryo with distinct germ layers for further organ formation.

Germ Layers and Their Functions

Endoderm: develops into internal organs.
Ectoderm: forms skin, nails, hair, and the nervous system.
Mesoderm: creates muscles, the skeleton, and systems like circulation.

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Description

This quiz focuses on the key characteristics of animals as outlined in Chapter 32 of Biology. It includes essential definitions such as multicellularity, heterotrophy, and the distinction between vertebrates and invertebrates. Perfect for students wanting to reinforce their understanding of animal biology.