Chapter 8/11 review test for Biology

what was the dominant idea introduced by Gregor Mendel

The theory of blended inheritance

what is blended inheritance

Traits of both parents are “blended” in the offspring

what is a gene

The basic unit of inheritance

how did Gregor Mendel follow traits

He did experimental crosses

What does a single chromosome contain

contains hundreds of genes

what is a Gene on DNA

A portion of DNA that governs one ore more genetic traits

what is an allele

Alternative version of a gene

how many alleles do each gene usually have

each gene has two or more

what is a genotype

allelic makeup responsible for the phenotype

what is a phenotype

physical expression of a genetic trait

what is a dominant Allele

variation of a gene that has complete control influencing the phenotype

how can a dominant allele be expressed as a phenotype

the allele needs only one copy of the dominant allele to be expressed

what is a recessive allele

an allele that requires two copies of the allele to be represented within the phenotype

what is a homozygous in alleles

Individual has two copies of the same allele

what does it mean to be heterozygous in alleles

individual has two different alleles (Aa)

how do different alleles from mutations arise

Changes in DNA sequence form random occurrence and not because needed

What does a harmful mutation mean

recessive alleles in which heteros are not affected but have negative impact on function

what does a neutral mutation mean

a new allele protein identical to original in which does nothing

What does a beneficial mutation mean

rarest of mutations, improve functionality

what is a genetic cross

A cross is a controlled mating experiment for examination of particular traits from inheritance

what is true breeding in genetic cross

homo dom and recessive bred together and kids have same phenotype as dom parent

what is the F1 generation

A heterozygous gen from P gen and look like dominant parent

what is the F2 gen

bred from F1 gen to get a predictable gen that is 3:1 dom to recessive

what is the Law of Dominance

a Dominant allele will have exclusive control over the phenotype of an organism when paired with others

what is the Law of Segregation

two copies of the gene will separate in meiosis and end u pin different gametes

what is the Law of independent Assortment

Genes do not influence each other with regard of the assortment of alleles into gametes

what is Incomplete Dominance

A heterozygous results in a blend of the traits being mixed together

what is the definition of multiple Alleles

occurs when 3 or more alleles are present for a gene not just 2

what is co dominance

the phenotype displays both alleles like in zebras

what is Epistasis

the phenotype display is based off the results of other alleles

what is a polygenic trait

a trait that is determined by two or more genes (height)

how can a disorder be inherited by offspring the three reasons

show and have the disorder

be asymptomatic but a carrier for the disorder

the disorder is on the chromosome itself (X chromosomes)

where can mutations on individual genes be found

on autosomes or the sex chromosomes

what does it mean to be autosomal recessive for a disorder

the person has to be recessive or two recessive alleles

what are the parents of autosomal recessive disease pts

the parents are heterozygous for the disorder and have 25% of passing gene

what are autosomal dominant conditions

one copy of the gene causes the disease

what determines the sex of a child

The SRY (Sex-determining Region of the Y chromosome)

what are sex-linked disorders referring to

disorders found on the X chromosome

who will usually give the Child the male the disease

the Mother usually

why is inbreeding bad

increases the risk that recessive alleles remain within the population

what is Evolution

the gradual genetic change that occurs in populations of organisms over time

what is the inheritance of acquired characteristics

organisms physically develop traits that are unknowingly passed onto offspring

what is natural selection introduced by Darwin

genes that display for traits fit better for survival result in those individuals having a better chance to reproduce

what is the term survival of the fittest mean

those with the greatest chance to have babies and spread their genes into the environment

what an Adaptation

a heritable trait that aids in the survival and reproduction of an organism in present environment

what is acclimation

acclimation Is the process of the body currently responding to stressors within environment itself, happen individually

how does adaptation or evolution occur within natural selection

pressures from environment result in traits that excel within particular organisms that will then pass the trait onto the next generation

where does change like evolution usually start at

evolution starts at the population level

what are the three evolutionary forces that create change

Mutation

natural Selection

Genetic Drift

what do mutations do for evolution

introduce a new source of alleles that can create change in positive negative or neutral ways

what does predation have to do with natural selection

form of natural selection as those not best with defense are picked off an those with better defense will live to reproduce

What is directional natural selection

individuals of one extreme phenotype are favored

what are the conditions necessary for evolution

traits must be heritable

more offspring are produced than can survive

natural variability in traits

What is Genetic Drift

difference in traits that Arise in organisms as a results of random events leading to random changes in allele frequency

what is the definition of genetic bottleneck

the population is forced into a small population and only those that survived pass their genes (from large to small)

what are homologous structures

a sharing of structure as in anatomy not in function

what are vestigial structures

leftover parts that are not used in modern day but still appear within the body

what are analogous structures

structures of anatomy that are used in the same function but not made out of the same material (wings of a butterfly VS wings of a bat)

what is convergent evolution

similar environmental pressures lead to distinctly shared features among distant organisms

what is an evidence of evolution through stones

the use of fossils give description

what is the chemical way in which we can observe evolution

through the use of DNA and is molecular biology

what is artificial selection

humans direct impact on genetic change through purposeful breeding on organisms