biol112 final lab exam

How do you calculate the genotypic frequency in a population?

Divide the number of individuals of a specific genotype by the total number of individuals in the population.

What is the formula for calculating the allelic frequency of a specific allele in a population?

(2 * number of homozygous individuals + number of heterozygous individuals) / (2 * total number of individuals).

What is the Hardy-Weinberg Equilibrium?

It is a mathematical model for a sexually reproducing population where allele and genotype frequencies do not change across generations, meaning it is not evolving.

What are the five processes that can alter allele and genotype frequencies in a population, causing evolution?

Natural Selection, Sexual Selection, Genetic Drift, Gene Flow, and Mutation.

The five conditions for a gene to be in Hardy-Weinberg equilibrium are the absence of mutation, no gene flow, random mating, a large population size, and no _.

natural selection

Why is genetic variation considered essential for evolution to occur?

Without variation, there are no traits for natural selection to act upon, leading to either the entire population surviving or the entire population dying.

What are deleterious alleles?

Alleles that result in a net negative impact on an organism's survival or reproductive chances.

What is heterozygote advantage?

A situation where the heterozygous genotype has a higher survival or reproductive rate than either of the homozygous genotypes.

How does heterozygote advantage maintain deleterious recessive alleles in a population?

Heterozygotes survive and reproduce at a higher rate, passing on both the advantageous and the deleterious alleles to the next generation.

If you are using a microscope with a 10x ocular lens and a 40x objective lens, what is the total magnification?

400x (10x ocular lens * 40x objective lens).

What is systematics?

The study of the relationships between different organisms and the evolutionary history that resulted in these relationships.

What is the primary focus of Taxonomy?

Naming, describing, and organizing species into hierarchical categories.

What is the primary focus of Phylogeny?

The ancestral history of organisms, focusing on which species are related and share common ancestors.

In a cladogram, what is the term for the group of organisms currently being studied?

Ingroup.

In a cladogram, the _ is a reference group used as a basis for comparison, representing an ancestral state.

outgroup

A new, derived character state is known as an _.

apomorphy

What is a synapomorphy?

A derived character state that is shared by two or more taxa and is used to define a clade.

What is an autapomorphy?

A derived character state that is unique to a single branch or taxon on a cladogram.

The ancestral character state in a cladogram is referred to as a _.

plesiomorphy

What is a node on a cladogram?

A branching point that represents a common ancestor from which two or more lineages diverge.

What is the principle of parsimony in constructing cladograms?

The idea that the simplest cladogram, with the fewest evolutionary changes, is usually the best hypothesis.

Organisms that are hermaphroditic, possessing both male and female reproductive organs, are described as _.

monoecious

What is meant by the term 'Alternation of Generations' in a plant's life cycle?

The life cycle includes both a multicellular diploid stage (sporophyte) and a multicellular haploid stage (gametophyte).

What is the primary difference between a rhizoid and a true root?

True roots have vascular tissue for transport, while rhizoids are simpler structures that primarily function as anchors.

Why is water necessary for fertilization in both mosses and ferns?

Both have flagellated sperm that must swim through water to reach the egg.

Is the dominant stage in a moss life cycle haploid or diploid?

Haploid, as mosses are gametophyte-dominant.

What cellular process produces spores in plants?

Meiosis.

In plants, what cellular process produces gametes?

Mitosis.

What cellular process produces gametes in animals?

Meiosis.

What are three reasons fungi are considered more closely related to animals than to plants?

They both use chitin, store energy as glycogen, and belong to the Opisthokonta supergroup (ancestor had a single posterior flagellum).

How do fungi obtain their food?

They are heterotrophic decomposers that perform external digestion by secreting exoenzymes and then absorbing the nutrients.

What is the fusion of cytoplasm from two parent mycelia in fungi called?

Plasmogamy.

Plasmogamy in fungi results in a _ cell, often denoted as (n + n).

dikaryotic

What is the fusion of nuclei in a fungal dikaryotic cell called?

Karyogamy.

Karyogamy in fungi results in the formation of a _ (2n) cell.

diploid

Which fungal phylum is characterized by having flagellated spores and gametes (zoospores)?

Phylum Chytridiomycota.

Which fungal phylum forms a thick-walled sexual structure called a zygosporangium?

Phylum Zygomycota.

Which fungal phylum is known for forming arbuscular mycorrhizae and has no known sexual structures?

Phylum Glomeromycota.

Which fungal phylum produces sexual spores (ascospores) in a sac-like cell called an ascus?

Phylum Ascomycota.

Which fungal phylum produces sexual spores (basidiospores) on a club-shaped cell called a basidium and typically lacks asexual reproduction?

Phylum Basidiomycota.

The fruiting body of a mushroom belongs to which fungal phylum?

Phylum Basidiomycota.

A lichen is a symbiotic association between a fungus (mycobiont) and a _ (photobiont).

photosynthetic partner (alga or cyanobacterium)

What is the defining characteristic of animals in Phylum Porifera?

They lack true tissues and have a cellular level of organization.

What is the function of choanocytes (collar cells) in sponges?

They generate water flow through the sponge and capture food particles.

What is the function of the osculum in a sponge?

It is the large exit opening through which water leaves the sponge's body.

The unique ability of sponge cells to transform into any other cell type is called _.

totipotency

What are the two defining features of Phylum Cnidaria?

The presence of cnidocytes (stinging cells) and radial symmetry.

Cnidarians are _, meaning they have two embryonic germ layers: the ectoderm and endoderm.

diploblastic

What are the two main body forms found in Cnidaria?

The sessile polyp form and the free-swimming medusa form.

What is the name of the single-opening digestive chamber in cnidarians that also functions in circulation and as a hydrostatic skeleton?

Gastrovascular cavity.

What are the three types of body cavities found in triploblastic animals?

Acoelomate (no cavity), Pseudocoelomate (partially lined cavity), and Coelomate (fully lined cavity).

During embryonic development in _, the blastopore becomes the mouth.

protostomes

During embryonic development in _, the blastopore becomes the anus.

deuterostomes

What type of cleavage is characteristic of protostome development?

Spiral and determinate cleavage.

What type of cleavage is characteristic of deuterostome development?

Radial and indeterminate cleavage.

What body cavity type is found in Phylum Nematoda (roundworms)?

Pseudocoelomate.

What are three key characteristics of the phylum Arthropoda?

A chitinous exoskeleton, segmented bodies, and paired, jointed appendages.

What are the defining characteristics of Subphylum Chelicerata (e.g., spiders, scorpions)?

They possess chelicerae (fang-like mouthparts), have no antennae, and typically have four pairs of legs.

How do centipedes (Class Chilopoda) differ from millipedes (Class Diplopoda)?

Centipedes have one pair of legs per segment and are carnivorous, while millipedes have two pairs per segment and are herbivorous.

What are the three defining characteristics of Subphylum Hexapoda (insects)?

Three body regions (head, thorax, abdomen), six legs, and one pair of antennae.

What is a key characteristic of Subphylum Crustacea (e.g., crabs, shrimp) that distinguishes them from other arthropods?

They have two pairs of antennae.

What unique system do echinoderms use for locomotion, feeding, and gas exchange?

The water vascular system.

Adult echinoderms typically exhibit _ symmetry, but their larvae are bilaterally symmetrical.

pentaradial

Why are echinoderms, despite their adult radial symmetry, classified within the Bilateria?

Their larval stage is bilaterally symmetrical, indicating a bilateral ancestor.

What are the five hallmark characteristics of all chordates?

A notochord, a dorsal hollow nerve cord, pharyngeal slits, a post-anal tail, and an endostyle/thyroid gland.

Which chordate subphylum retains all five key chordate characteristics in its adult form?

Subphylum Cephalochordata (lancelets).

Adults of which chordate subphylum lose most chordate features, retaining only the pharyngeal slits and endostyle?

Subphylum Urochordata (tunicates).

What two key features define the Subphylum Vertebrata?

The presence of vertebrae and a cranium (skull).

The superclass _ includes jawless fish like hagfish and lampreys.

Agnatha

What is the defining feature of the superclass Gnathostomata?

The presence of jaws.

The class _ includes cartilaginous fishes such as sharks, skates, and rays.

Chondrichthyes

The group _ includes all bony vertebrates, from ray-finned fish to tetrapods.

Osteichthyes

What key adaptation allowed amniotes (reptiles, birds, mammals) to reproduce completely on land?

The amniotic egg.

What are two defining characteristics of Class Mammalia?

The presence of hair and mammary glands.

A _ skull, with one temporal opening, is characteristic of mammals.

synapsid

A _ skull, with two temporal openings, is characteristic of most reptiles and all birds.

diapsid

Trace the path of deoxygenated blood from the body through the right side of the mammalian heart.

Body -> Vena Cava -> Right Atrium -> Right Ventricle -> Pulmonary Artery -> Lungs.

Trace the path of oxygenated blood from the lungs through the left side of the mammalian heart.

Lungs -> Pulmonary Veins -> Left Atrium -> Left Ventricle -> Aorta -> Body.

How many chambers are in the heart of a fish?

Two (one atrium, one ventricle).

How many chambers are in the heart of an amphibian?

Three (two atria, one ventricle).

Most non-avian reptiles have a three-chambered heart, but _ have a true four-chambered heart.

crocodilians

On an ECG, what does the P wave represent?

Atrial depolarization (contraction).

On an ECG, what does the QRS complex represent?

Ventricular depolarization (contraction).

On an ECG, what does the T wave represent?

Ventricular repolarization (relaxation).

What is the formula for calculating Mean Arterial Pressure (MAP)?

MAP = (Systolic Blood Pressure + 2 * Diastolic Blood Pressure) / 3.

What are the three main physiological reflexes that constitute the diving response?

Bradycardia (slowed heart rate), peripheral vasoconstriction, and a blood shift (in deep dives).

What part of the brain processes the stimuli for the diving response?

The brainstem, specifically the medulla oblongata.

What two primary stimuli trigger the dive response in mammals?

Cold water contacting the face and breath-holding (apnea).

Term: A slower than normal heart rate.

Bradycardia.

Term: The maximum time a diving animal can remain submerged before switching to anaerobic metabolism.

Aerobic Dive Limit (ADL).

What are the two primary functions of the excretory system?

To remove nitrogenous wastes and regulate water and salt balance (osmoregulation).

What is the functional unit of the vertebrate kidney?

The nephron.

Where in the nephron does the filtration of blood occur?

The renal corpuscle (which consists of the glomerulus and Bowman's capsule).

Why should large molecules like proteins and blood cells NOT be found in the filtrate?

They are too large to pass through the filtration barrier of the renal corpuscle.

In which part of the nephron does the majority of reabsorption of water, salts, and glucose occur?

The proximal tubule.

The primary function of the descending limb of the Loop of Henle is the reabsorption of , while the ascending limb actively reabsorbs .

water; salt

The final concentration of urine is primarily determined in the _, a process regulated by the hormone ADH.

collecting duct

What is the function of Antidiuretic Hormone (ADH)?

It increases the permeability of the collecting duct to water, leading to greater water reabsorption and more concentrated urine.

What common substances inhibit the release of ADH, leading to increased urination?

Alcohol and caffeine.

What is osmosis?

The movement of water across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.