HW 12 monohybrid dihybrid crosses, probability

From Gregor Mendel's experiments with pea plants it is concluded that: 1.only ___ allele determines the phenotype in heterozygous individuals 2.the inheritance of alleles of __ gene does not affect the inheritance of alleles of another gene

1. 1 2.1

Gene therapy steps (6)

1. a functioning gene is inserted into the DNA of an inactivated virus 2. the viral vector is presented to the affected cells in a specific tissues 3. the vector is enclosed in a vesicle and moved into the cell 4. the vesicle breaks down and releases the vector with the host cell 5.the viral vector injects its DNA into the nucleus of the host cell 6.the new gene is transcribed by the cell in order to make protiens

The environment can affect a genetic trait in 2 ways: 1. can limit the available ______________ required by an organism for normal development 2. increased exposure to certain environmental factors can increase the risk of developing a specific ___________.

1. resources 2. disease

Diploid organisms, such as humans and other mammals, have two copies of their genetic material in the form of homologous chromosomes. One copy of each homologous chromosome is passed to the organism from each of its parents during the process of fertilization. For many genetic traits, a diploid organism is said to be either homozygous or heterozygous at a particular locus, depending on whether its parents passed down two of the same or two different alleles for that specific sequence. What 2 things describe a heterozygous locus? 1. ______ different alleles are found in a particular position on homologous chromosomes 2. the alleles at a particular position on homologous chromosomes of an individual with two ______-___________ parents for different alleles.

1.2 2.true breeding

Mendel's Law of segregation says : 1. gametes carry _____ allele for each trait 2.each parent provides ______ allele for each gene

1.one 2.one

4 Mutations if occur in a protein-coding gene 1. 2. 3. 4.

1.silent 2.nonsense 3.missense 4.nonsense

3 basic types of DNA mutations 1. 2. 3. -

1.substitution 2.insertion 3.deletion -inversion

What 3 things can lead to mutations in the DNA? 1. 2. 3.

1.uncorrected DNA replication errors 2.exposure to x-ray radiation 3.chemicals in some pesticides

Incomplete dominance occurs when a HETEROZYGOTE displays a phenotype that is intermediate between the phenotypes of both HOMOZYGOTE parents. The blending that occurs from incomplete dominance results in a phenotype in the offspring that is distinguishable from the parents, such as a gray sheep or an orange-colored moth.

A BLACK sheep and a WHITE sheep produce a GREY lamb. A moth with RED wings and a moth with YELLOW wings produce a moth with ORANGE wings

Codominance occurs when BOTH ALLELES in a HETEROZYGOTE are simultaneously expressed and the offspring's phenotype is distinguishable from that of both homozygous parents. Since both traits are expressed at the same time in an individual with blood type AB and in roan colored cows, these are examples of codominance

A mother with type A blood and a father with type B blood have a daughter with AB blood. A WHITE cow and a RED bull have a calf that is WHITE with RED spots

Complete dominance occurs when the phenotype of the heterozygote is indistinguishable from that of the HOMOZYGOUS RES&DOM parent, as is the case with the pea plant example.

A pea plant with SMOOTH seeds and a plant with WRINKLED seeds produce a plant with SMOOTH

_________________ is the addition of genetic material to a chromosome through extra replication of a chromosomal section.

Duplication

A ____________ is a heritable phenotype that can differ between two individuals.

character

Examples of character:

color, shape, length

A ______________ mutation occurs when one or more bases are removed from the sequence.

deletion

Insertion and deletion mutations may result in _______________ mutations. In a ______________ mutation, the addition or deletion of a base causes the reading frame to change. For example, if the sequence UCAUCAUCAUCA were mutated into the sequence UCAUCAUUCAUCA by an insertion of a U at the seventh position, the amino acid sequence of the resulting polypeptide would change from Ser-Ser-Ser-Ser to Ser-Ser-Phe-Ile. Notice that every amino acid following the frameshift mutation is mutated.

frameshift

A genotype is the ________ makeup of an organism. Example: BB

genetic

Dominant alleles are any allele that can ________ the presence of a different allele.

hide

An _____________ mutation occurs when one or more bases are added to the sequence

insertion

An ______________ mutation occurs where a chromosome breaks, and its genetic material is reinserted in a different orientation

inversion

Why are linked genes often inherited together?

linked genes are close together on the same chromosome

A ___________ mutation is a mutation that changes the codon to one that encodes a different amino acid, the mutation is termed A mutation that changes the codon UCA to CCA is a missense mutation because the new codon CCA encodes proline (Pro) instead of Ser.

missense

A ______________ mutation is a mutation that changes a codon to a stop codon, prematurely terminating the translation of the polypeptide. A mutation that changes the codon UCA to UAA is a nonsense mutation because UAA is one of the three stop codons

nonsense

A deletion of a single _____________ is a type of DNA mutation that results in a change in the reading frame of an mRNA.

nucleotide

An allele is ______ version of a gene. Example: B or b

one

Dominance affects the ____________ derived from an organism's genotype.

phenotype

A phenotype is the ___________ expression of a gene. Example: baldness

physical

A locus is the _____________ of a gene on a chromosome

position

Autosomal recessive disorder

rr

A __________ mutation is a mutation that changes a codon to a different codon that encodes the same amino acid. For example,a mutation that changes the codon UCA to UCU is a silent mutation because both codons encode the amino acid serine (Ser).

silent

Using gel electrophoresis, DNA fragments are separated by: ___________ DNA fragments move through the gel more quickly than ____________ fragments move.

smaller, larger

A _________________ mutation occurs when one base is replaced with a different one.

substitution

A ________ is a version of a particular character.

trait

__________________ is the rearranging of genetic material between nonhomologous chromosomes without a net loss or gain of genetic material

translocation

Examples of trait:

white, wrinkled, long

An example of gene therapy is: replacing a disease-causing allele for a gene with a ______-____________ allele (normal allele)

wild-type