Lab 3 Exam Review

Who is the father of genetics?

Gregor Mendel

What did Gregor Mendel study?

Pea plants to understand pattern of inheritance

Why did Mendel study pea plants?

They self-pollinate, cross fertilize, and have several traits that only have two forms

Heredity

transmission of traits from one generation to the next

Genetics

study of heredity

What was the P generation?

Purple flower and white flower parent pea plants

F1generation

Only purple flower pea plants

F2 generation

705 purple flowers and 224 white flowers

What results did Mendel draw from his results?

Genes are inheritable and one form of a feature always concealed the other form in the first generation after the cross

Alleles

different versions of genes that give it designation

Dominant alleles

the visible form

Recessive allele

the hidden form

Genotype

set of alleles carried by an organism; genetic make-up

Phenotype

physical traits or observable features

Heterozygous

has two different copies of alleles

Homozygous

has two copies of the same allele

Law of Independent Assortment

features are inherited separately

Law of Segregation

two alleles for a character separate during gamete formation

Punnet square

predictions of the genotype and phenotype of offspring

Dihybrid cross

one in which two separate characters are being studied

Pedigrees

used to track genetics traits in a family

Are inherited illnesses dominant or recessive?

Recessive but can be passed down to offspring

Incomplete dominance

both alleles are expressed and will become “blended”

Pleiotropy

one gene influences many characters

Blood types in humans

the result of multiple alleles and codominance

Codominance

neither allele is recessive and the phenotypes of both alleles are expressed

Example of pleiotropy

the sickle cell mutation can cause many physical changes

Polygenic inheritance

the effect of many genes on a single characters; multiple genes controlling one trait

Linked genes

located close together on the same chromosome and tend to be inherited together

Theory or evolution

how we are unite and diverse through our environments

Who is the father of evolution?

Charles Darwin

What did Darwin study?

He observed island finch species to mainland finch species

What did Darwin notice about the finch species?

He noticed how they vary in beak sizes; smaller beaks would burrow their beaks into small crevices to gain access to their food source

What fossil did Darwin observe and what present day animal did it look like?

Glyptodonts; armadillos

Survival of the fittest

the animals that are better suited for their environment will live and mate to deliver offspring that will have the more favorable characteristics

Who was also credited for evolution?

Alfred Russel Wallace

Natural selection

process where organisms have a specific trait that is desirable that will survive an altering environment; causes adaptive evolution

Natural selection in bacterial organisms

has led to an increase in anti0biotic resistance alleles

Descent with modification

all living things have descended from a succession of ancestral species

Fitness

how well one genotype survives and reproduces compared to other genotypes

Adaptation

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

When does adaptation occur?

when a change in genetic variation occurs over time

Variance

difference among individuals in a population

Divergent evolution

when there is a common ancestor

Convergent evolution

when there are no common ancestors but shared similar function and appearance

Population

group of the same species living in the same place at the same time

Gene pool

all forms of genes in a population

Microevolution

a gene that becomes favorable in the natural selection process and will become more frequent in the gene pool

Mutations

can happen spontaneously or when induced

Genetic drift

change in gene pool due to chance; allows for genetic variation to occur

Founder effect

when an organism leaves they become the founding member of the new, isolated population; will have a more uniform gene pool

Bottle neck effect

reduction of certain individuals in a population due to famine, disease, or rapid environmental changes; remaining members are a random sample of original population

Gene flow

changes in allele frequency due to the migration of reproductive individuals from one population to another

Macroevolution

major changes in history as there are formation of new species, occurrence of mass extinctions, and diversification of new forms of life

Speciation

process that separates a single population into two or more isolated populations

Homologous structures

anatomical features that resemble each other but have different functions due to shared ancestry

Analogous structures

anatomical features that resemble each other with similar functions but no shared ancestry; result of convergent evolution

Vestigial traits

non function features that were once functional with our ancestors

Biogeography

geographic distribution of species

Molecular biology

DNA sequences are more similar in closely related species

Sympatric speciation

new species evolve in same geographic area

Allopatric speciation

populations become more geographically separated which prevent gene flow

DNA

deoxyribose nucleic acid; holds instructions for all living things and is a double helix with nucleotides

Nucleotides pieces:

5 carbon sugar, phosphate group, nitrogenous base

DNA pairing rules

Adenine and Thymine; Guanine and Cytosine

The condensation of DNA

DNA → histones → nucleosome → chromatin

Semi-conservative replication

parent strand is preserved

RNA differences

single-stranded, sugar in RNA is ribose, Thymine is replaced by uracil

Transcription

occurs in nucleus and uracil is used instead of thymine

mRNA

messenger RNA; molecule that results from transcription

Translation

occurs in cytoplasm and when an mRNA codon is translated into an amino acid to build a protein

Translation involves the coordination of which kinds of RNA

mRNA, rRNA, tRNA

rRNA

makes ribosomes with protein

mRNA

contains code to make proteins in the form of codons

tRNA

carries amino acids to ribosome

Mutation

any change in the nucleotide sequence of DNA; can be spontaneous and induced

Sexual reproduction

involves haploid cells combining to form a new diploid organism to introduce variation

Haploid

contain only one copy of each chromosome

Meiosis

production of gametes; results in 4 unique haploid cells, two rounds of division, cells are used for sexual reproduction

Mitosis

results in 2 identical diploid cells, one round of division, cells are used for growth and repair

Non-disjunction

occurs when chromosomes or sister chromatids fail to separate properly

Example of nondisjunction

Trisomy 21 which is when a person receives three copies of chromosome 21 aka down syndrome