mammal_flashcards
What are the defining traits of mammals?
Hair, mammary glands, middle ear bones, diaphragm, and endothermy.
What is the function of mammalian hair?
Protection, insulation, camouflage, sensory input, and communication.
What is the evolutionary origin of mammals?
Mammals evolved from synapsid ancestors.
What is the significance of mammary glands?
They produce milk to nourish young mammals.
What is the mammalian integument?
The skin, including hair, glands, and specialized structures.
What are sebaceous glands?
Glands producing sebum to keep skin and hair lubricated.
What are scent glands used for?
Communication, marking territory, and defense.
What is keratin?
A protein in hair, nails, and horns providing strength and protection.
What are vibrissae?
Sensory hairs (whiskers) that detect environmental stimuli.
What are quills?
Defensive hairs modified into sharp spines.
What are true horns?
Keratinized sheaths with a bony core found in ruminants.
What are antlers?
Bony structures shed annually, found in deer species.
What types of teeth do mammals have?
Incisors, canines, premolars, and molars.
What are carnassial teeth?
Sharp teeth used for slicing meat in carnivores.
What type of teeth do herbivores have?
Broad, high-crowned molars for grinding vegetation.
What is the dental formula for humans?
2 incisors, 1 canine, 2 premolars, and 3 molars per jaw side.
What are ruminants?
Herbivores with a four-chambered stomach for digesting plant material.
What are omnivores?
Animals that eat both plants and animals, including humans and bears.
What are insectivores?
Animals that feed primarily on insects.
What is filter feeding?
Feeding method used by some aquatic mammals like baleen whales.
How does body size affect metabolism?
Smaller mammals have faster metabolisms and need more food per unit size.
What is endothermy?
The ability to regulate body temperature internally.
Why do small mammals eat frequently?
They have high surface area-to-volume ratios, causing rapid heat loss.
What are monotremes?
Egg-laying mammals like the platypus and echidna.
What are marsupials?
Mammals with pouches for carrying young, like kangaroos.
What are placental mammals?
Mammals with internal gestation supported by a placenta.
What is estrus?
The reproductive cycle when female mammals are fertile.
What are precocial young?
Young born well-developed and able to move shortly after birth.
What are altricial young?
Young born underdeveloped, requiring parental care.
How do mammals nourish their young?
Through milk produced by mammary glands.
What determines litter size in mammals?
Mortality rates and species-specific reproductive strategies.
What is territoriality?
The defense of a specific area for feeding, mating, or raising young.
What is a home range?
An area where an animal lives and forages but does not defend.
What factors affect territory size?
Food availability, body size, and reproductive needs.
What is the evolutionary significance of synapsids?
They are the ancestors of modern mammals.
What are therapsids?
Advanced synapsids that gave rise to mammals.
What are the key mammalian evolutionary traits?
Hair, endothermy, specialized teeth, and live birth.
What are mammalian diaphragm muscles used for?
Breathing by expanding the chest cavity.
What are middle ear bones?
Three small bones (malleus, incus, stapes) for sound transmission.
What are mammalian incisors used for?
Biting and cutting food.
What are canines used for?
Piercing and holding prey.
What is echolocation?
Navigation and hunting using sound waves, found in bats and dolphins.
What is hibernation?
A state of reduced metabolic activity to survive cold conditions.
What is torpor?
Short-term hibernation during cold nights or food shortages.
What are marsupial examples?
Kangaroos, koalas, and opossums.
What are the three mammalian subclasses?
Monotremes, marsupials, and placentals.
What distinguishes placental mammals?
Internal gestation supported by a placenta.
What are insectivores known for?
Eating insects using sharp, pointed teeth.
What is convergent evolution?
Unrelated species evolving similar traits due to similar environments.
What sense is highly developed in most mammals?
Smell, due to well-developed olfactory regions.
What is binocular vision?
Vision with overlapping fields for depth perception.
What is tactile sensing?
Detecting environmental changes using touch-sensitive skin or whiskers.
What adaptations help mammals survive in deserts?
Water retention, nocturnal behavior, and burrowing.
What helps aquatic mammals stay warm?
Thick blubber layers for insulation.
What do hooves help with?
Efficient movement across different terrains.
What is plantigrade locomotion?
Walking with the entire foot touching the ground, like humans and bears.
