Chapter 24: Animal Evolution and Diversity Flashcards
(45 cards)
What are the three main characteristics that all animals share?
Multicellular, Heterotrophs, Eukaryotes
These characteristics define the biological classification of animals.
What are the two categories of animals?
Invertebrates, Chordates
Invertebrates lack a backbone, while chordates include all vertebrates.
What percentage of animal species are invertebrates?
More than 95%
Invertebrates are the most diverse group of animals.
What are the three main characteristics that all chordates have at some point in their life?
- Nerve cord
- Notochord
- Pharyngeal pouches
What is homeostasis?
Stable internal conditions in an organism
Animals maintain homeostasis through various physiological processes.
How do animals gather and respond to information?
Using receptors and nerve cells
The nervous system plays a crucial role in responding to stimuli.
What systems do animals use to obtain and distribute oxygen and nutrients?
Circulatory, Respiratory, Digestive systems
These systems work together to ensure cellular respiration occurs.
What is the process by which most animals reproduce?
Sexual reproduction
This process promotes genetic diversity among offspring.
Fill in the blank: The _______ is the innermost germ layer that develops into the digestive tract and respiratory system.
Endoderm
What type of body symmetry do animals with radial symmetry have?
Round shape with multiple equal halves
Radial symmetry is common in aquatic animals.
What is cephalization?
Concentration of sense organs and nerve cells at the anterior end
This trait is typically found in bilaterally symmetrical animals.
What are the two major types of feedback involved in maintaining homeostasis?
Negative feedback, Positive feedback
What is a cladogram?
A diagram that shows relationships among animal clades
Cladograms illustrate evolutionary relationships based on body plans.
What are the major groups of modern invertebrates?
- Sponges
- Cnidarians
- Arthropods
- Roundworms
- Flatworms
- Annelids
- Mollusks
- Echinoderms
What is the main adaptation of sponges?
Have cells and tiny openings all over their bodies
They are considered the most ancient animals.
What type of symmetry do cnidarians exhibit?
Radial symmetry
Cnidarians include jellyfish and corals.
What are the two types of bony fishes?
- Ray-finned fishes
- Lobe-finned fishes
What is the significance of the notochord in chordates?
It becomes the backbone
The notochord is a defining feature of chordates.
What adaptations do amphibians have for life on land?
- Lungs for breathing
- Stronger limbs
- Moist skin with mucous glands
True or False: All vertebrates are chordates.
True
Fill in the blank: The _______ is the outermost germ layer that develops into the nervous system and outer skin layer.
Ectoderm
What is the primary characteristic of arthropods?
Segmented bodies and jointed appendages
Arthropods are the most abundant group of animals.
What is a characteristic of roundworms?
Unsegmented bodies and a digestive tract with two openings
Roundworms are also known as nematodes.
What do all worms have in common?
- Cells
- Tissues
- Organs
- Organ systems
- Bilateral symmetry
