Exam Review: Biology for Non-Science Majors II

A comprehensive set of flashcards covering key concepts from Chapters 18 and 19 relevant to the exam.

Definition of Animals

Animals are multicellular, eukaryotic organisms that are characterized by their ability to move, consume organic material, breathe oxygen, and reproduce sexually.

Origin of Animals

Animals likely originated from a variety of organisms, particularly from single-celled eukaryotes such as choanoflagellates.

Cambrian Explosion

The Cambrian Explosion refers to a period approximately 541 million years ago when there was a rapid diversification of life and the appearance of many major groups of animals.

Abundance of Invertebrates

Invertebrates make up about 95% of all animal species, showcasing their immense diversity and abundance in various ecosystems.

True Radial Symmetry

True radial symmetry is a body plan in which body parts are arranged around a central axis, allowing for symmetry in multiple directions.

Choanocytes

Choanocytes are specialized flagellated cells found in sponges that create water currents for filtering food particles.

Nutrient Transport by Sponges

Sponges transport nutrients through the movement of water, allowing them to filter feed while facilitating gas exchange.

Cnidarians

Cnidarians are a group of animals that includes jellyfish, corals, and sea anemones, characterized by the presence of cnidocytes, which are specialized cells for capturing prey.

Similarities between Tapeworms and Fungi

Both tapeworms and fungi feed by absorbing nutrients from their host or the environment, exhibiting a parasitic or saprophytic lifestyle.

Characteristics of Mollusks

Mollusks typically possess a soft body, a muscular foot, a mantle that may produce a shell, and a radula for feeding.

Characteristics of Earthworm, Polychaetes, and Leeches

These annelids show segmentation, have a coelom, and possess various adaptations for their environments, such as setae in polychaetes.

Segmented Animals with Exoskeleton

Examples include arthropods like insects and crustaceans, which have a chitinous exoskeleton and exhibit segmentation.

Spiders and Horseshoe Crab

Both belong to the phylum Arthropoda, with spiders categorized as arachnids and horseshoe crabs classified as chelicerates.

Three Parts of an Adult Insect

An adult insect is comprised of three main body regions: the head, thorax, and abdomen.

Complete Metamorphosis

Complete metamorphosis is a developmental process in insects where the organism undergoes distinct life stages: egg, larva, pupa, and adult.

Difference between Lampreys and Fishes

Lampreys lack jaws and have a circular mouth, while fishes possess jaws and typically have paired fins.

Evolution of Jaws

Jaws evolved from modifications of gill arches in early vertebrates, allowing for improved feeding capabilities.

Characteristics of Finned Fish

Finned fish usually have a streamlined body, scales, gills for breathing underwater, and fins for propulsion and maneuvering.

Carboniferous Era Divergence of Amphibians

During the Carboniferous era, vertebrate evolution led to the divergence of amphibians from their fish ancestors as they adapted to life on land.

Adaptation of Replies for Life Cycle on Land

Key adaptations include the development of lungs and skin that prevents desiccation, allowing amphibians to thrive in terrestrial environments.

Flightless Birds Adaptation

Flightless birds such as penguins and ostriches lack the adaptation of wings for flight, relying on other physical adaptations for survival.

Defining Mammals

Mammals are characterized by the presence of mammary glands, warm-blooded metabolism, and typically hair or fur.

Lemurs and Natural Habitat

Lemurs are primates native to Madagascar, primarily inhabiting forests and play a crucial role in their ecosystem.

Define Anthropoids and Primates

Anthropoids are a subgroup of primates that include monkeys, apes, and humans, distinguished by traits such as larger brains and greater social complexity.

Functions of Prehensile Tails

Prehensile tails are used for grasping and holding onto branches, aiding in mobility and stability in arboreal environments.

Animal Groups without Tails

Some animal groups, such as certain apes and frogs, can be classified as tail-less, adapting to their environments.

Animals Capable of Making Simple Tools

Certain species, including some primates and birds, have been observed using simple tools to assist in foraging and survival.

Closest Relatives of Humans

The closest living relatives of humans are chimpanzees and bonobos, sharing a common ancestor from about 6 to 8 million years ago.

Difference between Chimp and Human DNA

Humans and chimpanzees share approximately 98-99% of their DNA, with differences attributed to specific genetic modifications over time.

Bipedalism as a Hominin Trait

Bipedalism is the ability to walk on two legs, a key characteristic that differentiates hominins from other primates.

First Hominins Group Using Stone Tools

The first group of hominins recognized for using stone tools are known as the Oldowan hominins.

Origin of Genus Homo

The genus Homo is believed to have originated around 2.8 million years ago, with Homo habilis being one of the earliest species.

Best Description of Neanderthals

Neanderthals were a species of archaic humans known for their robust build and adaptation to cold environments in Europe.

Evolution of Humans according to Fossil and Genetic Evidence

Fossil and genetic evidence suggest that modern humans evolved in Africa and migrated outwards, with some interbreeding with Neanderthals.

Origin of Modern Mitochondrial DNA

Modern mitochondrial DNA traces back to a single female ancestor, often referred to as 'Mitochondrial Eve', who lived approximately 150,000 to 200,000 years ago.

Human Skin Color as Adaptive Compromise

Human skin color varies as an adaptation to UV radiation levels, balancing the need for vitamin D synthesis with protection against skin damage.