Genetics and Evolution Lecture Review

A set of practice flashcards based on the lecture notes covering genetics, evolution, embryonic development, animal features, and physiological systems.

What are the traditional Linnaean taxonomic categories in order?

Kingdom, Phylum, Class, Order, Family, Genus, Species.

What can be used instead of Linnaean taxonomic categories for any genetic group?

Clade or Taxon.

What is the difference between phylogenetic trees and cladograms?

Phylogenetic trees show evolutionary time and amount of change; cladograms show only relative relationships.

Why are embryos useful when comparing phylogenetic relationships?

Similarities in embryonic development can show evolutionary connections that aren't obvious in adult forms.

What does 'morphology' mean?

The study of the form and structure of organisms.

What are the three domains of life?

Bacteria, Archaea, and Eukarya.

Who proposed the endosymbiosis theory and what is the story behind it?

Lynn Margulis proposed that ancestral wall-less archaeans engulfed bacteria that became mitochondria and, in some cases, chloroplasts.

What is some evidence supporting the theory of endosymbiosis?

Mitochondria and chloroplasts have their own DNA, double membranes, and reproduce independently.

What is the clade 'Protists' and how are protozoans and algae categorized?

Protists are eukaryotes that are not plants, animals, or fungi; protozoans are predatory or parasitic, while algae are photosynthetic.

Which protozoan group did animals evolve from?

Choanoflagellates.

What is a scientific theory?

A scientific theory is extremely well-documented, broad-based, and actively investigated.

How do all evolutionary changes begin?

All evolutionary changes start with new gene mutations.

Do mutations arise because an individual or species 'needs' a new adaptation?

No, mutations arise at random and not because of need.

Do individuals evolve?

No, individuals do not evolve — populations or species do.

Can evolution occur because organisms learn to do new things?

No, evolution happens due to genetic mutations, not because of learning.

Over what time frame does evolution occur?

Evolution occurs over many generations, and the time periods can vary.

What are the three levels of evolution?

Microevolution, Speciation, and Macroevolution.

What is microevolution?

Microevolution is genetic shifts within a population over many generations; it is measurable and always happening.

What are examples of mechanisms that drive microevolution?

1. Artificial selection 2. Natural selection 3. Gene flow 4. Non-random mating 5. Unintended selection.

What is speciation?

Speciation is the formation of new species, commonly through isolation and genetic divergence.

What is macroevolution?

Macroevolution is large-scale evolutionary changes, such as the appearance of new groups or mass extinctions.

Who was Charles Darwin?

A British scientist who proposed natural selection as the main mechanism of evolution.

What influenced Darwin's thinking about Earth's age?

Geologists who presented compelling evidence that Earth is very old.

Who developed the idea of natural selection at the same time as Darwin?

Alfred Russel Wallace.

What is the name of Darwin's famous book, and when was it published?

On the Origin of Species, published in 1859.

What did Darwin's book propose?

It provided evidence for natural selection and suggested that processes could lead to new species.

Did Darwin and Mendel know about each other's work?

There is no evidence that Darwin knew about Mendel's work.

What are the stages of early embryonic development?

Zygote → Morula → Blastula → Gastrulation → Formation of three germ layers (Endoderm, Mesoderm, Ectoderm).

What is the function of the endoderm, mesoderm, and ectoderm in embryos?

Endoderm: forms digestive tract and organs; Mesoderm: forms muscles, skeleton, circulatory system; Ectoderm: forms skin and nervous system.

What does 'true tissues' mean and which animals lack them?

True tissues are organized layers of specialized cells; sponges lack true tissues.

What is the difference between Radiata and Bilateria?

Radiata have radial symmetry, Bilateria have bilateral symmetry.

What does diploblastic vs. triploblastic mean?

Diploblastic animals have two germ layers, and triploblastic animals have three germ layers.

What are ecdysozoans and lophotrochozoans?

Both are protostomes; Ecdysozoans include arthropods and nematodes, Lophotrochozoans include mollusks and annelids.

What is protostome development?

Mouth forms first; includes some acoelomates, pseudocoelomates, and coelomates.

What is deuterostome development?

Mouth forms second; includes echinoderms and chordates.

What key cell type helps sponges feed?

Choanocytes — create water currents and trap food particles.

What special cells do cnidarians have and what are their two forms?

Cnidocytes (with nematocysts); Polyp and Medusa forms.

What is a lophophore and which three phyla have it?

A lophophore is a ciliated feeding structure; found in Bryozoa, Brachiopoda, Phoronida.

What are the key features of flatworms?

Bilateral symmetry, cephalization, simple or absent digestive system.

Why are rotifers called 'wheel animals'?

They have a ciliated structure that looks like spinning wheels.

What are common features of mollusks?

Mantle, muscular foot, radula, many have shells.

How is segmentation useful in annelids?

Allows for flexibility and complex movement.

How do nematodes differ from flatworms and annelids?

Nematodes have a complete digestive tract, non-segmented bodies, and are covered by a cuticle.

What is the predator strategy of velvet worms?

They shoot sticky slime to trap prey.

What does 'Arthropod' mean and what do all arthropods have?

'Jointed foot'; All have exoskeletons, segmented bodies, and jointed appendages.

How can you tell an insect from an arachnid?

Insects have 6 legs and 3 body parts; arachnids have 8 legs and 2 body parts.

What are echinoderms' key features?

Radial symmetry, water vascular system, endoskeleton.

What is the water vascular system in echinoderms?

A hydraulic system used for movement, feeding, and respiration.

Why are echinoderms grouped with chordates?

Both are deuterostomes.

What features do all chordates have at some point?

Notochord, dorsal nerve cord, pharyngeal slits, post-anal tail.

Who are the two invertebrate chordate groups?

Tunicates (sea squirts) and lancelets.

What is the defense strategy of hagfish? Do they have teeth?

Produce slime; no true teeth.

What do lampreys have that hagfish don’t?

Vertebrae.

What did jaws evolve from?

Modified gill arches.

What are some adaptive features of cartilaginous fish?

Lateral line system, electroreceptors, constantly replaced teeth.

What are features of ray-finned fish?

Evolved in freshwater; bony skeleton protects gills.

Why are lobe-finned fish important to evolutionary biologists?

They are the ancestors of tetrapods.

Who are the tetrapods?

Four-limbed vertebrates — amphibians, reptiles, birds, mammals.

How do amphibians breathe and reproduce?

Breathe through skin and lungs; reproduction requires water.

What are amniotes and what is special about their eggs?

Reptiles, birds, mammals; have shelled eggs or placentas.

Which amniotes are ectotherms and which are endothermic?

Ectotherms: reptiles; Endotherms: birds and mammals.

What is the purpose of feathers other than flying in birds?

Insulation, display, waterproofing.

Which bones are part of a bird’s wing?

Modified forelimb bones.

What are key features of mammals?

All give milk, have hair, and three middle ear bones.

What are the three types of mammals?

Monotremes (lay eggs), Marsupials (pouch), Placentals (develop fully in uterus).

What are the four types of adult animal tissues and their functions?

Epithelial (covering), Connective (support), Muscle (movement), Nervous (communication).

What is homeostasis?

Maintaining a stable internal environment.

What is a negative feedback loop?

A process where the body reverses a change to maintain balance.

What are major functions of the integumentary system?

Protection, temperature regulation, sensory input, vitamin D production.

What glands are in the integumentary system and their functions?

Sweat glands (cooling), sebaceous glands (oil), mammary glands (milk).

What structures are part of animal integumentary systems?

Scales, feathers, hair, shells.

What is the difference between homeothermy and poikilothermy?

Homeothermy means maintaining a constant body temperature, poikilothermy means body temperature varies.

How does endothermy differ from ectothermy? Give examples.

Endotherms generate internal heat; ectotherms rely on external heat sources.

Can you name some invertebrates that are endothermic?

Certain bees and some large moths.

How can an ectotherm maintain homeothermy?

By using behavioral strategies like basking or seeking shade.

How do ectothermic animals adjust their temperatures behaviorally?

Basking in the sun, burrowing, seeking shade.

Why is it advantageous to store energy as fat instead of carbs or proteins?

Fat stores more energy per gram and is lighter to carry.

What is an essential nutrient?

A nutrient that must be obtained from the diet.

How can vegans get all essential amino acids without supplements?

By combining whole plant foods.

What is the difference between a vitamin and a mineral?

Vitamins are organic; minerals are inorganic.

What are examples of fluid feeders, suspension feeders, and detritivores?

Fluid feeders: mosquitoes; Suspension feeders: clams; Detritivores: earthworms.

Name two animals that rely on mutualistic symbionts for nutrition.

Cows and corals.

How do some simple animals obtain nutrition without a complete digestive tract?

By absorption through their body surface.

List unique digestive adaptations in vertebrates not found in humans.

Baleen (whales), pharyngeal jaws (some fish), crop and gizzard (birds).

Describe the route and functions of the human GI tract.

Mouth → Esophagus → Stomach → Small Intestine → Large Intestine → Rectum.

What is bile, where is it made, and what does it do?

Bile is made in the liver and emulsifies fats.

What is the main role of the pancreas in digestion?

It secretes digestive enzymes and bicarbonate into the small intestine.

What is peristalsis?

Muscular contractions that move food through the digestive tract.

Trace a glucose molecule from the small intestine to a body cell.

Absorbed into the bloodstream → Insulin helps glucose enter cells.

Why do cells need oxygen during aerobic respiration?

To accept electrons for ATP production.

When is CO₂ released during aerobic respiration?

During the Krebs cycle.

What prevents moist lungs from sticking together?

Surfactant.

How does counter-current exchange in fish gills work?

Blood flows opposite to water flow, maximizing O₂ diffusion.

How do insects breathe?

Through spiracles connected to trachea.

Describe the bird respiratory system.

Air flows one-way through lungs using air sacs.

Name the main parts of mammalian lungs.

Pharynx → Larynx → Epiglottis → Trachea → Bronchi → Bronchioles → Alveoli.

What carries oxygen in the blood?

Hemoglobin in red blood cells.

How is most CO₂ carried back to the lungs?

As bicarbonate ions in the blood plasma.

List five functions of a circulatory system.

Transport O₂/CO₂, nutrients, hormones, immune cells, waste removal.

Name animals with an open circulatory system.

Insects and mollusks.