If a single gene has more than 3 alternative forms, it is called:
Multiple alleles
Mendel's Principle of Independent Assortment states that different pairs:
Alleles segregate independently of each other.
A cross where we follow the inheritance of two pairs of alleles is called
Dihybrid cross
Within the human body, different cells have different characteristics or phenotypes. For example, neurons look and behave very differently from hepatocytes (liver cells). How can this be explained considering that all cells within a person were derived fr
Each cell type within a person must contain different proteins.
Traits controlled by organellar DNA do not show Mendelian inheritance because
organellar DNA is not partitioned with the nuclear genome by the process of meiosis. Mendelian inheritance depends on the orderly segregation of alleles during meiosis, followed by the random combination of gametes to which each contributes half the genet
Genomic imprinting leads to non-Mendelian inheritance because in genomic imprinting
In genomic imprinting,the phenotype caused by a specific allele is exhibited when the allele comes from one parent, but not from the other. The basis for genomic imprinting is the expression of a gene depending on passage through maternal or paternal germ
The distances between gene loci measured in terms of the frequency of recombination is indicated by a genetic ______.
map
The number of allele pairs that assort independently in an organism is generally much higher than the number of chromosome pairs. This phenomenon is due to
Crossing over
Huntington's disease is caused by a single dominant allele. It is a lethal disease, yet it persists in the human population. Which of the following statements best describes why?
Huntington's disease presents symptoms in mid-life, after most people have already had offspring.
Occasionally, chromosomes fail to separate during meiosis, leading to daughter cells that have an abnormal number of chromosomes. This phenomenon is called
Nondisjunction
A DNA specimen that contains 30% guanine has ________ thymine.
20%
The mechanism of DNA replication is
semiconservative
Eukaryotic cells store their DNA in the form of linear chromosomes. This creates problems for replication of DNA at the ends of the chromosomes because
DNA polymerase can only synthesize DNA in the 5' to 3' direction.
______________ are made in replicating the lagging strand of DNA, but are not made during leading strand DNA replication.
Okazaki fragments
During DNA replication, the enzyme ___________, catalyzes the elongation of new DNA by adding, to the 3' end of the previous nucleotide, new nucleotides that are complementary to a DNA template.
DNA polymerase
Which molecule catalyzes covalent bond formation between fragments of DNA
Ligase
DNA consists of two antiparallel strands of nucleotides held together by
Hydrogen bonds
Epigenetics
Exceptions to chromosomal inheritance. DNA sequence does not change, but the genome is modified by adding a methyl (CH4) or acetyl group, which silences genes to not be expressed, forcing the genome to compact very tightly.
Methylation of DNA
In normal people, hyper methylation turns off igf2. In famine like conditions, hypo methylation occurred, turning on the igf2. Methylation patterns are inherited.
What charge is on the phosphate group of a DNA molecule?
Negative charge
Describe the characteristics of a nucleotide.
Polar, net negative charge, soluble in water (cells are 60% water)
Difference between RNA and DNA
RNA has an OH at 2'. DNA has a H at 2'.
Where will the purine base attach?
OH- at 3' end.
How do bases match up perfectly in DNA?
Due to their antiparallel structure.
In what stage of mitosis is DNA replicated?
S Phase
What happens at the G2 phase?
Once DNA has been replicated in S phase, at the G2 phase DNA is separated and replicated.
How does thiropurine work?
Purines are modified with a sulfur base instead of an O group. This makes the molecule not stable enough, preventing it from base pairing and thus halting DNA replication. The cell will then go through apoptosis and die.
What is the difference in DNA replication between eukaryotes and prokaryotes?
In eukaryotes, DNA is linear. In prokaryotes, DNA is circular, with multiple origins of replication.
In Mendelian genetics, are genes linked or non linked?
Linked
What is true of genes if they are on the same chromosome and close together?
Inherited together more frequently.
If genes are inherited together, what is true of the phenotype of the offspring?
They will look similar to their parents.
If the offspring look dissimilar to their parents, what is true of their gene inheritance pattern?
Their inherited genes were most likely recombinants or cross over occurred.
If the inherited genes are recombinants, is the offspring parental or non-parental?
Non-parental
Which is smaller, the X or Y chromosome?
Y chromosome, therefore there is much less genetic information on it.
What are trisome chromosomes an example of?
Aneuploidy
What chromosome are most male dominant disorders located on?
The X chromosome.
What is the ratio of genotypes for a cross between two heterozygotes?
9:3:3:1
How is DNA read?
3' to 5'
How is DNA generated?
5' to 3'
What is the purpose of RNA primase on the Okazaki fragments?
Primase adds the nucleotides, then polymerase can start.
What is the purpose of multiple origins of replication?
DNA is super long, and with only one origin, DNA would not be replicated fast enough and the cell would die.