Biology Final Exam - Untested Content

what is a pedigree?

a visual representation of how a specific trait is passed down through generations

what is the square symbol in a pedigree?

a male

what is a circle symbol in a pedigree?

a female

what does it mean if the symbol is shaded in a pedigree?

the individual expresses that trait

what do horizontal lines connect in a pedigree?

mating partners

what do vertical lines connect in a pedigree?

connects parents to offspring

autosomal dominant

a pattern of inheritance where a single altered copy of a gene from one parent is sufficient to cause a genetic condition

autosomal recessive

a pattern of inheritance where a genetic trait or disorder appears only when an individual inherits to copies of a mutated gene - one from each parent

What is the expression of a dominant trait?

needs only one allele to be expressed

What is the expression of a recessive trait?

needs two alleles to be expressed

incomplete dominance

neither allele is completely dominant, the heterozygote results in a blend

co dominance

both alleles are expressed equally and simultaneously

polygenetic traits

traits controlled by multiple genes, resulting in a wise range of phenotypes

sex linked traits

genes located located on the sex chromosomes (X or Y)

Aneuploidy

the presence of an abnormal number of chromosomes in a cell

what is the cause of aneuploidy

caused by nondisjunction - failure of chromosomes to separate during meiosis

monosomy

missing a chromosome

trisomy

having an extra chromosome

structural or damage errors to chromosome structure

deletion, duplication, inversion, and translocation

What is the goal of amniocentesis

detect chromosomal abnormalities or metabolic errors before birth

what is the timing of amniocentesis?

14th - 16th week of pregnancy

what is the method/source of amniocentesis?

amniotic fluid

What is the goal of chorionic villus sampling?

detect chromosomal abnormalities, genetic disorders, and metabolic disorders. It is done faster and earlier than amniocentesis

what is the timing of chorionic villus sampling?

8th - 10th week of pregnancy

what is the method/source of chorionic villus sampling

placental tissue

What is the goal of newborn screening?

detects metabolic, genetic, hormone related, or functional disorders that are not otherwise apparent at birth

What were Aristotle and Judeo-Christian Cultures ideas of “evolution”

believed species were fixed (unchanging) and arranged on a scale of increasing complexity

What did carolus Linnaeus develop?

the binomial nomenclature system for naming species

What was Cuvier’s idea?

Catastrophism

Catastrophism

the geological and biological theory that Earth’s features, including mountain building, canyon formation, and mass extinctions, were primarily shaped by sudden, violent, and short lived events rather than slow, gradual processes.

What did Hutton hypothesize?

Gradualism

Gradualism

the theory that change occurs through slow, consistent, and incremental steps over long periods rather than abrupt, massive shifts

What did Lyell hypothesize?

uniformitarianism

uniformitarianism

the foundational principle in geology that states that the same natural laws and processes that operate in the universe today have always operated in the past

Who was Jean Baptiste de Lamarck

first to propose how life changes —> although it was later proved incorrect

use and disuse

body parts that are used extensively become larger/stronger; others deteriorate

inheritance of acquired characteristics

modification gained during an individuals lifetime are passed to offspring

are acquired characteristics passed down?

no not acquired

Components of Baptiste de Lamarcks theory

use and disuse; inheritance of acquired characteristics

What were the two pillars of Darwins logic?

variation and overproduction

variation

individuals in a population are unique

over population

species produce more offspring then the environment can support

what does overpopulation lead to?

competition

what is the sequence of evolution by natural selection?

overproduction —> variation —> selection —> adaptation

what are the four pieces of evidence for evolution?

direct observation, homology, artificial selection, and fossil record

what is an example of direct observation

antibiotic resistance

homology

similarities from common ancestors

homologous structures

some underlying structure but different functions

vestigial organs

remenents of structures that served a purpose in their ancestor but are now useless

molecular homology

all of life uses the same universal genetic code

phenotypic variation

observable differences in physical traits

genetic variation

differences in the actual DNA sequence

artificial selection

humans mimic natural selection by breeding organisms for specific traits proving populations can change overtime based on selective pressures

fossil record

provides a chronological record of how ancient organism gave rise to modern ones; showing the transition of life forms over millions of years

what is the flow of pheno and geno typic variation

genetic variation —> phenotypic variation —> natural selection acts on the phenotype

allele frequency

proportion of a specific allele

what equation is used for allele frequency?

p + q = 1

genotypic frequency

proportion of specific combination of alleles

what equation is used for genotypic frequency?

p² + 2pq + q² = 1

what are the five factors affecting allele frequency?

genetic drift, gene flow, mutation, non random mating, natural selection

types of genetic drift

founder effect and bottleneck effect

founder effect

a few individuals start a new colony. their small set of genes doesn’t represent the original group

the bottleneck effect

a disaster kills most of the population. Survivors are there by luck, changing the gene pool

Gene flow

the movement of alleles into or out of a population. this increases genetic diversity and reduces differences between populations

mutation

raw material for evolution. while rare, it is the only way to get a brand new allele.

non random mating

inbreeding - does not change allele frequencies but increases homozygous genotypes

natural selection

only factor that is adaptive. It accumulates favorable genotypes by ensuring the best fit individuals have offsprings

what are the three species concepts?

biological, morphological, and ecological

biological species concept

a species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups

what is the biological species concept best applied to

living, sexually reproducing organisms

what is the limitation of the biological species concept

it cannot be applied to asexual organisms, fossils, or many plants that freely hybridize

morphological species concept

defines a species based on shared observable physical traits, such as shape, size, color, and anatomical structures

what are the limitations of the morphological species concept?

subjectivity

what is the morphological species concept best applied to?

fossil records, asexual organisms, and field studies where reproductive or genetic data is unavailable

ecological species concept

defines a species as a set of organisms adapted to a specific, unique ecological niche

ecological species concept limitations

flexibility in life history, difficulty determining competitive boundaries, and subjectivity in defining niche gaps

what is the ecological species concept best applied to?

asexual organisms and species with high rates of hybridization or limited reproductive date

what are the five prezygotic barriers

habitat, temporal, behavioral, mechanical, and behavior isolation

habitat isolation

they live in different places

temporal isolation

they mate at different times

behavioral isolation

they have different courtship rules

mechanical isolation

differences in reproductive structures prevent successful mating

gametic isolation

sperm cannot fertilize the egg due to biochemical incompatibility

what are the post zygotic barriers

reduced hybrid viability, reduced hybrid fertility, and hybrid breakdown

reduced hybrid viability

genetic incompatibilities between two species cause hybrid offspring to be frail, unhealthy, or die before reaching reproductive maturity

reduced hybrid fertility

hybrid offspring from two different species are sterile or have significantly reduced fertility

hybrid breakdown

first generation offspring of two different species are viable and fertile, but subsequent generations are sterile, weak, or inviable

allopatric speciation

process by which new species arise when a population is geographically separated by a physical barrier preventing gene flow

sympatric speciation

the process by which new species evolve from a single ancestral population while inhabiting the same geographic location, without physical barriers

gradualism

evolution is a small steady crawl. species accumulate small changes over vast periods of time

punctuated equilibrium

evolution happens in fits and starts. Long periods of no change are punctuated by brief rapid bursts of change

taxonomy

the science of naming, describing, and classifying organisms based of shared characteristics

phylogeny

focuses on evolutionary history and the actual genetic relationships among organisms based on shared ancestry

binomial nomenclature

the formal, two part scientific naming system for living organisms

example of binomial nomenclature

Tyto alba (T. alba)

Hierarchical classifications

1. domain

2. kingdom

3. phylum

4. class

5. order

6. family

7. genus

8. species

root

earliest common ancestor of all organisms in a tree

nodes (branch points)

represent a point where a lineage split into two

sister taxa

two organisms that share an immediate common ancestor. they are each others closest relatives

basal taxon

a lineage that evolved early from the root and remains unbranched