Biology Unit 3 Flashcards
Unit 3 - SAQs
What does a longer Nasal Passage mean on a skeleton?
The Longer the nasal passage means that linked to increase reliance of olfactory sensitivity.
What does the orbital bone signify?
Larger orbital bones may indicate bigger eyes, improving vision in low-light environments, useful for nocturnal or deep-sea species.
What is the function of the Incisors?
Smaller incisors suggest a diet focused on softer foods, while larger, robust incisors indicate adaptation for cutting or gnawing tougher materials like meat or fibrous plants.
What is the function of the Canines?
Larger canines suggest a diet or behavior involving tearing flesh or display for dominance, while smaller canines indicate a diet less reliant on meat or reduced aggression.
What is the function of the Premolars?
Broad, flat premolars suggest a diet involving grinding or crushing plant material, while sharper, more pointed premolars indicate a role in shearing or processing meat.
What is the function of the Molars?
Large, flat molars with complex cusps indicate a diet heavy in grinding tough plant material, while smaller, simpler molars suggest a softer diet or more carnivorous habits.
What is the function of the Auditory Bulla?
A large, robust auditory bulla suggests acute hearing adaptations, often for detecting predators or prey, while a smaller bulla may indicate less reliance on auditory senses.
Skull function?
Protects the brain; supports facial structures.
Mandible function?
Lower jaw; holds lower teeth; allows for chewing.
Clavicle function?
Collarbone; connects the shoulder blade to the sternum.
Scapula function?
Shoulder blade; provides attachment for muscles.
Elbow function?
Allows for flexion and extension of the forearm.
Ribs function?
Protect the heart and lungs; aid in breathing.
Humerus function?
Upper arm bone.
Radius function?
Forearm bone; rotates the forearm.
Ulna function?
Forearm bone; forms the elbow joint with the humerus.
Vertebrae function?
Vertebrae protect the spinal cord and support the body.
Carpals function?
Wrist bones; allow for wrist movement.
Metacarpals function?
Hand bones; connect the carpals to the phalanges.
Pelvis function?
Supports the lower body; protects internal organs.
Sacrum function?
Fused vertebrae; forms part of the pelvis.
Phalanges (Hand) function?
Finger bones; allow for fine motor skills.
Phalanges (Foot) function?
Toe bones.
Femur function?
Thigh bone; longest bone in the body.
Tibia function?
Shin bone; weight-bearing bone of the lower leg.
Tarsals function?
Ankle bones; allow for ankle movement.
Patella function?
Kneecap; protects the knee joint.
Fibula function?
Smaller bone of the lower leg; provides stability.
Metatarsals function?
Foot bones; connect the tarsals to the phalanges.
Pairetal Bone function?
One of two bones forming the sides and roof of the cranium.
The Mandible function?
The lower jawbone; the only movable bone in the skull.
The Mental Foramen function?
A small hole on the mandible that allows passage of the mental nerve and blood vessels.
The nasal bone function?
Two small bones forming the bridge of the nose.
The Frontal bone function?
Forms the forehead and upper part of the eye sockets.
The Sphenoid Bone function?
A complex, bat-shaped bone located in the middle of the skull base; contributes to several structures.
The Zygomatic Bone function?
Cheekbone; forms part of the eye socket.
The Optic Canal function?
Opening in the sphenoid bone through which the optic nerve passes.
The Temporal Bone function?
Forms part of the side and base of the skull; houses the inner and middle ear structures.
The Vomer Bone function?
Forms the posterior and inferior part of the nasal septum.
AHow do scientist compare evolutionary relationships?
- DNA Sequence
- Anatomy
- Physiology
The function of the Maxilla?
Upper jawbone; holds the upper teeth.
What are the 4 fossil types?
- Body Fossils
- Trace Fossils
- Cast Fossils
- Petrified Fossils
- Amber
- Ice
- Tar
- Tools
Description of Bone Fossil?
Mineralized remains of an organism’s skeletal system.
Description of Shells Fossils?
Mineralized remains of an organism’s outer protective layer.
Description of Rock Imprints Fossils?
Impressions or molds left in rock by organisms.
Description of Exoskeleton Fossils?
Mineralized remains of an organism’s external skeleton.
What is the Rock Cycle?
- Molten rock cools
- Rocks break down
- Sediments piles up and squeeze together
- Rocks get squeezed and heated deep underground
- Metamorphic rocks can melt
- Its a cycle where rocks cahnge from one type to another and back again many times
What is Selective Breeding?
The process of humans breeding organisms with desired traits to produce offspring with those traits.
What is Artificial Selection?
A form of selective breeding where humans intentionally choose which organisms reproduce to enhance specific traits.
what is Natural Selection?
The process where organisms with advantageous traits survive and reproduce more successfully, leading to evolutionary change over time.
What is Adaptation?
A trait or behavior that improves an organism’s ability to survive and reproduce in its environment.
What is relative dating?
A method used by scientists to determine the age of fossils or rock layers by comparing them to other known layers.
What are transitional fossils?
Fossils that show intermediate traits between ancestral and modern species, providing evidence of evolution.
What are adaptive traits?
Inherited characteristics that increase an organism’s chance of survival and reproduction in a specific environment.
What is a homologous structure?
Similar anatomical structures shared by related species, inherited from a common ancestor. Anatomically similar, different function, divergent evolution.
What is a Analogous feature?
Anatomically different structures with similar functions, resulting from convergent evolution.
What is a Node?
Hypothetical ancestor giving rise to two or more daughter taxa; represents a point of divergence in a cladogram.
What is a Clade?
Group of species or organisms sharing similar features, representing all descendants of a common ancestor.
What is a Taxon/Outgroup?
Most distantly related group in a cladogram; serves as a reference point for comparison. Not necessarily a clade.
What is a Brand?
Line connecting nodes and taxa in a cladogram, representing evolutionary lineages.
What is a Root?
Starting point of a cladogram, representing the initial common ancestor.
What is the T.O.E?
Evolution explains how species change over time. Organisms with helpful traits survive and pass them to their offspring, leading to new species.
What are the 4 pieces of evidence for T.O.E?
- Fossils show species change.
- Similar DNA points to common ancestry.
- Embryos of different species look alike early on.
- Similar body structures show adaptation.
What is Divergent Evolution?
Related species become different (e.g., finches).
What is Convergent Evolution?
Unrelated species develop similar traits (e.g., bird and bat wings).
What is Gene Flow?
gene migration is the result of the movement of individuals into or out of populations (migration, translocation, mating between diff pop)
What is Mutation?
Change in DNA sequence; source of new genetic variation.
What is Genetic Bottleneck?
Sharp reduction in population size, reducing genetic diversity.
What is Genetic Drift?
Random fluctuations in allele frequencies, especially in small populations.
What is Stabilizing Selection?
Natural selection favoring intermediate phenotypes.
What is Sexual Selection?
Natural selection based on mate attraction and reproduction success.
What is Directional Selection?
Natural selection favoring one extreme phenotype.
What is Disruptive Selection?
Natural selection favoring both extreme phenotypes, potentially leading to speciation.
What are the four mechanisms of Evolution?
- Genetic Mutation
- Gene flow
- Genetic Drift
- Natural Selection
Explain Gene Mutation?
- DNA Mutation is random
- Natural Selection acts of the favored trait or eliminates unfavored traits
New Alleles are formed
Explain Genetic Drift?
- Alteration in allelic frequency by chance or random events
- Genetic Bottleneck and Founders Effect
What does is a Body Fossil?
These are the actual remains of the organism, such as bones, teeth, shells, and plant material.
What is a Trace Fossil?
These provide evidence of the activities of ancient organisms, including footprints, burrows, and coprolites (fossilized dung).
What is a Petrified Fossil?
These occur when organic material is replaced with minerals, turning it into stone-like structures, often seen in trees (petrified wood).
What is speciation?
How does isolation affect speciation?
What are the 6 pieces of evidence for T.O.E.?
- Fossil Record
- Comparative Anatomy
- Molecular Biology
- Embryology
- Biogeography
- Observational Evidence
Explain Fossil Records?
Shows gradual changes and transitional forms between species.
Explain Comparative Anatomy?
Similar structures (e.g., forelimbs) indicate common ancestry.
Explain Molecular Biology?
DNA similarities (e.g., humans and chimpanzees) suggest shared ancestry.
Explain Embryology?
Similar early developmental stages across species indicate common origins.
Explain Biogeography?
Unique adaptations in isolated environments (e.g., Darwin’s finches) reflect evolutionary processes.
Explain Obersevational Evidence?
Real-time examples, like natural selection in peppered moths, demonstrate evolution in action.
What is a Common Ancestor?
Look for the point at which all the branches split; this represents the common ancestor of the organisms.
4 Different Mechanisms for Evolution
- Natural Selection
- Genetic Drift
- Gene Flow
- Mutation
Explain Natural Selection?
Process where organisms with favorable traits survive and reproduce more successfully.
Types of Natural Selection?
- Directional Selection – Favors one extreme trait (e.g., giraffes with longer necks).
- Stabilizing Selection – Favors the average trait (e.g., human birth weight).
- Disruptive Selection – Favors both extremes (e.g., black and white moths).
What is Genetic Drift?
Random changes in allele frequency due to chance, affecting small populations.
Types of Genetic Drift?
- Bottleneck Effect – Population size is drastically reduced (e.g., cheetahs).
- Founder Effect – Small group colonizes a new area, reducing genetic diversity (e.g., Amish communities).
What is Gene Flow?
Movement of alleles between populations, increasing genetic diversity (e.g., pollen transfer, human migration).
What is Mutation
Random changes in DNA that create new alleles, providing genetic variation.
Types of Mutations
- Beneficial Mutation – Provides an advantage (e.g., antibiotic resistance in bacteria).
- Neutral Mutation – Has no significant effect.
- Harmful Mutation – Reduces survival (e.g., genetic diseases).
What is Microevolution?
Small-scale changes in allele frequencies within a population over a short period (e.g., antibiotic resistance in bacteria).
What is Macroevolution?
Large-scale evolutionary changes that lead to the formation of new species over long periods (e.g., evolution of whales from land mammals).
What is Coevolution?
The process where two or more species evolve in response to each other (e.g., bees and flowers adapting together for pollination).
