Medical Biology Chapters 4-6 Quizlet

Telophase I

Telophase I

Cell divides into two diploid daughter cells

Prophase II

Nuclear membrane breaks, spindle fibers form

Telophase II

Cell divides into two haploid daughter cells

Independent Assortment

Homologous chromosomes pair randomly during metaphase I

Autosomes

Chromosomes #1-22 in human body cells

Trisomy X

XXX chromosome condition in females

Klinefelter Syndrome

XXY chromosome condition in males

Jacob's Syndrome

XYY chromosome condition in males

Geologic Time Scale

Chronological scale of Earth's history

Phylogenetic Tree

Model showing evolutionary relationships between species

Genetic Variation

Differences in DNA contributing to evolution

Chromosomes

Thread-like structures carrying genetic information

Prophase I

Chromosomes pair up and spindle fibers form

XX Chromosomes

Female sex chromosome pair

XY Chromosomes

Male sex chromosome pair

Anaphase I

Spindle fibers separate homologous chromosomes

Haploid

Single set of chromosomes (e.g., sperm or egg)

Meiosis

Process of creating gamete cells for sexual reproduction

Homologous Chromosomes

Inherited pairs from each parent in sexual reproduction

Sister Chromatids

Identical copies of a chromosome created during interphase

Crossing Over

Exchange of chromosome segments during prophase I

Fertilization

Mixing genetic material from egg and sperm for offspring

Gametogenesis

Final stage for haploid sex cells to be fertilized

Monohybrid Cross

Cross involving one trait

Dihybrid Cross

Cross involving two traits

Translocation

Segment of one chromosome moves to another non-homologous chromosome

Balanced Translocation

Exchange reciprocated, genetic material amount remains constant

Gene Mutation

Changes in DNA sequence of a single gene

Silent Mutations

Alter codon but not amino acid produced

Missense Mutations

Change codon and amino acid produced

Nonsense Mutations

Change codon, create STOP codon halting amino acid production

Frameshift Mutation (Insertion)

Addition of nucleotides to codon

Frameshift Mutation (Deletion)

Deletion of nucleotides from codon

Trinucleotide Repeat Expansions

DNA polymerase duplicates DNA segments repeatedly

Gene Deletion

Missing gene from chromosome

Gene Translocation

Segment of chromosome moves to non-homologous chromosome

Rock Cycle

Process changing physical and chemical structure of rock

Erosion Forces

Agents like water, ice, wind, and gravity shaping land

Sedimentary Rocks

Formed from compressed sediments over time

Index Fossils

Short-lived, widespread, easily identifiable fossils

Sediments

Small rock or mineral pieces

Fossil Record

Preserved traces or remains of ancient organisms

Strata

Layers of sedimentary rock indicating different time periods

Homologous Structures

Similar structures with different functions indicating evolution

Analogous Structures

Different structures with similar functions

Vestigial Structures

Remnants of structures hinting at organism's past

Exponential Growth

Rapid growth due to surplus resources

Natural Selection

Survival of individuals with adaptive traits

Gametes

Sex cells with half the number of chromosomes

Interphase

Phase where chromosomes duplicate before cell division

Metaphase I

Homologous chromosomes line up at the equator

Y Chromosome

Determines male sex in offspring

Metaphase II

Sister chromatids align randomly for genetic variation

Anaphase II

Spindle fibers separate sister chromatids

Diploid

Two sets of chromosomes (e.g., body cells)

Centromere

Links sister chromatids in the center of a chromosome

Karyotype

Stained image showing homologous chromosomes

Intersex

Individuals with atypical sex chromosome numbers

Mutagen

Environmental factor altering DNA, increasing mutation risk

Chromosomal Mutations

Mutations in chromosome segments or full chromosomes

Gene Duplication

Chromosomes receive extra copy of existing gene

Gene Pool

Collection of alleles in a population

Allele Frequency

Proportion of a specific allele in a gene pool

Hardy-Weinberg equation

p^2 + 2pq + q^2 = 1

Microevolution

Observable allele frequency changes in a population

Stabilizing Selection

Intermediate phenotypes favored over extremes

Directional Selection

One extreme phenotype favored over others

Disruptive Selection

Both extremes favored over intermediates

Gene Flow

Genes moving in/out of a population

Genetic Drift

Allele frequency change due to chance events

Founder Effect

Genetic drift in small isolated populations

Sexual Selection

Mating preference influencing evolution

Intrasexual Selection

Male-male competition for mating success

Intersexual Selection

Male traits attracting females for mating

Adaptive Radiation

Diversification of a species into many

Kin Selection

Nature selecting traits in a kin group

Altruism

Self-sacrificing behavior for kin group benefit