Test 1 Genetics

Timeframes for early genetics

10,000-12,000 years ago shows evidence of plant and animal domesticantion

Aristotle’s theory of inheritance

• Daughters = Mothers

• Sons = Father

what is the pangenesis theory

every part of the body contains genetic information that is transfered by gemmules (particles) from that body part to the embryo

what is preformationism

inside the egg and sperm is a fully formed tiny human that enlarges and develops over time

explain inheritance of aquired characterists

traits that an organism aquired in their life time passes to their off spring

what is blending inheritance

traits given to offspring are 50/50 from parents

Darwin discovered what theory in 1859

theory of evolution

describe Schleiden Schwann’s cell theory

1939-

• all life is made up of cells

• all cells come from preexisting cells

• cells are the fundemental function of living things

Who is the father of Modern Genetics

1822-1884 Greggor Mendel

What is Mendel’s discovery

the basic principles of heredity

In 1879 Walther Flemmind discoverd…

the division of chromosomes

Who discovered Germ-plasm theory

Weismann 1982

In 1902 Sutton located..

genes on chromosomes

In 1982 Katy Mullis discovered

polymerase chain reaction

Who beat the goverment in 2003, and cost billions

Craig Venter, human genome sequence

who discovered grough breaking gene editing

In 2012 Jennifer Doundna developed CRISPER editing

What is a genome

complete set of genetic instructions

Genome is like a…

Blueprint

• eithr RNA and DNA ( mostly DNA )

What are DNA wrapped around

Histomes

• specialized proteins

Alleles

different forms of genes

DNA structure

• A: adenine

• T: thymine

• G: guanine

• C: cytosine

Charguff’s Rule -

A=T

G+C

Central dogma is..

Theory of how information flows from DNA to RNA to proteins

DNA —→ RNA —> Protein

what are the three divisons of genetics

• Transmission : how genes are passed down

• molecular : studies function and structure of genes

• population : how groups of the same species makeup change over time

characteristics of a model organism

• ability to be reared in a lab environment

  • short generation time

  • cheap

• production of multiple progney

• ability to carry out controlled genetic crosses

• having previous knowledge about their genetic systems

Similarities of Eukaryotes & Prokaryotes

• contain DNA

• have plasma membrane

What cell is

• circular

• small

• no ordered arrangement

• no nucleus

prokaryotes

What cell is

• linear

• larger

• wrapped around histones

• genetic material around nuclear envelope

• has nucleus

Eukaryotes

What are homologous pairs

two sets of chromosomes

• humans have 23 pairs of chromosomes

describe the structure of a chromosome

• Centromere: point of attachment 

• Telomere : tips of linear chromosomes

• Sister chromatids: identical copy of chromosome

What would be the result if a chromosome did not have a kinetochore?

• Spindle microtubules would not attach to the chromosome.

• Some daughter cells would be missing a chromosome, others would have double

describe interphase

stage in the cell cycle where a cell grows, replicates DNA, and prepares cell division

what are the phases in Interphase

• G1: grows cell

• “Synthesis” S: DNA replication

  • sister chromatids

• G2: more growth and prep for cell division

• M phase: meiosis/mitosis

  • separation of cytoplasm

what is mitosis

separation of sister chromatids

What is phase 1 of mitosis

Interphase: centromeres form to pull DNA

What is phase 2 of mitosis

Prophase: condenses chromosomes

What is phase 3 of mitosis

Prometaphase: breaks down nuclear envelope

What is phase 4 of mitosis

metaphase: lines up in middle

Phase 5 of mitosis

Anaphase: separates sister chromosomes

What is phase 6 of mitosis

Telophase: creates cleave to separate cells

• begins cytokinesis

during meiosis I what happens

homologous chromosome pairs seperate

During Meiosis II

Sister chromosomes separate

Define male gamete production

Spermatogenesis

What is oogenesis

female gamete production

Reasons for Mendel’s Sucessn

1. had a good experimental model

2. took an experimental approach and analyzed results mathematically

What is a gene

inherited factor that determines a trait

Define allele

different variates if genes

Where do you locate an allele

locus

describe a set of alleles

genotype

heterozygous

2 different alleles at a locus

homozygous

2 of the same alleles at a locus

monohybrid crossed

a genetic cross where two parents differ in a single trait

Dominant is …

a version of a gene that is expressed, even with one copy

• AA Aa

Recessive is…

2 copies from each parent to express trait

• aa Aa

What is the principle of segregation

a living organism has 2 versions of each gene. when gametes are produced the 2 versions separate and each cell gets one version of the gene

What is the addition rule

the “or” rule

• it can be this “OR” this

What is the multiplication rule

the “and” rule

• it can be this “and” this

dihybrid crosses

examines 2 traits at a time

describe independent assortment

the way one gene is inherited from parent doesn’t affect how another gene is inherited

What is the Chi-square goodness of fit test

indicates the probability between observed (O) and expected (E) values are due to chance

What is the formula and steps for the Chi-square goodness of fit test

1. calculate chi-square

2. find chi-square value on table

3. interpret p-values

x²= (E+O)²/E

sexual determination

Sexual reproducing organisms have cells that go between haploid and diploid

explain what chromosomal is

X and Y chromosomes pair during meiosis, although they are not homologous

what do you call chromosomes that don’t determine sex

autosome

what is essential for chromosome paring in meiosis for men?

pseudoautosomal essential for XY chromosomes

explain genic

no distinct chromosomes determined by genes on undifferentiated chromosomes (plants, fungi, fish, protozoans

can sex be determined by environmental factors

yes

XX

females

XY

males

What organisms can you find XX&XY?

Insects, fish, amphibians, reptiles, mammals, humans

XO

Male

XX-XO chromosomes can be found in…

insects

ZW

Females

ZZ

Males

ZZ & ZW chromosomes

• Butterflies, birds some reptiles and amphibians 

Pseudoautosomal regions

short regions on the X and Y chromosomes that recombine during meiosis

What is SRY gene

sex-determining region Y gene

what is the role of SRY gene

produces a cascade of other gene products, and is the primary on-switch for male sex trait determination

what causes abnormal chromosome numbers

Non-disjunction of homologous chromosomes/ sister chromatids fail to separate correctly

what is the job of a Punnett Square

to determine the probability of progeny

What is a Barr body

dark spots in cells that are caused by a inactivation of the X-chromosome from having too many X’s

What are the types of dominance

1. Complete

2. Incomplete

3. Codominance

What is complete dominance

heterozygous phenotype is similar to one homozygous phenotype

what is incomplete dominance

homozygous and heterozygous mix to create a new phenotype

describe codominance

heterozygous phenotype includes phenotype of both homozygous

describe expressivity

the intensity in which a trait is being expressed

• everyone has a genotype that is expressed differently

What is penetrance

percentage of individuals is having a specific genotype that is expressed the expected phenotype

what are lethal alleles

alleles that cause death in early development

what is the ratio of lethal alleles

2/3 to 1/3

describe multiple alleles in a population

for one locus, more than two alleles are present within a group

What is gene interaction

effects of alleles at one locus influence alleles at another loci

Ratio of gene interaction

9:3:3:1

only one trait in gene interaction phenotype

What is epigenetic modification

inheritable changes in gene expression that doesn’t alter DNA

describe imprinting

process that controls gene expression based on whether if the gene is inherited from mom or dad

what is sex-influence

autosomal genes are expressed differently in male and female

what is sex-limited

autosomal gene expression is limited to one sex

describe Sex-linked

genes located at the sex chromosomes

What is the maternal effect

genotype of mother determines phenotype of offspring

what is cytoplasmic inheritance

genes typically inherited from one parent, usually mother, and result in extensive phenotypic variation in one family

what is a pedigree

pictorial representation of a family history, outline inheritance of characteristics

5 types of pedigrees

1. Autosomal recessive

2. Autosomal dominant

3. X-linked recessive

4. X-linked dominant

5. Y-linked traits