Ch 23 part 1
what is the difference between genotype and phenotype
genotype= the traits in the genes
phenotype= how those genes are expressed
A disorder is autosomal dominant. If 1 parent has the disorder and is a heterozygous and the other has the disorder, what is the chance each child will have the disorder
50%. the 1 disorder parent either will or wont pass the dominant chromosome to each child
If something is sexed linked in humans, which chromosomes is it own
What does it mean if someone has trisomy 4
they have 3 (trisomy) of chromosome 4
What are the 4 nucleotides for DNA?
What is the complementary strand for the following piece of DNA: GATCCAGT
adenine, guanine, cytosine, thymine
CTAGGTCA (A-T, G-C)
What does it mean if someone is heterozygous for a trait
they have both the dominant and recessive trait in their genotype
A disorder is autosomal recessive. Parent 1 has the disorder and is homozygous and does NOT have the disorder. What is the chance a child will have the disorder
0%. Since this is a recessive disorder and the parent 2 has 2 good copies then the children will all be carriers
A disorder is X-linked recessive, the mother has the disorder and the father does not. What chance do the daughters and sons have for having the disease
sons- 100% because the only x they get is from the mom so it will be recessive (disorder)
daughters-0%- they will get 1 good X (dominant) from the father and 1 bad (recessive) from the mother so they will all be carriers
What trisomy causes down syndome
trisomy 21
Explain what it means by DNA replication being semiconservative
What is the complementary mRNA strand for the following DNA strand: ATGACCTGA
after replication the DNA molecules will be made of 1 parent (original) and 1 daughter stand (copy)
UACUGGACU (DNA-RNA: A-U, G-C, C-G, T-A)
There are 2 options for a plants height, short and tall, you arent sure which is dominant or recessive. You find a heterozygous plant that is short. Is tall or short the dominant trait
heterozygous have 1 dominant and 1 recessive trait and always express the dominant. since the heterozygous plant is short then short must be the dominant trait
Explain incomplete dominance and what genotype it affects
The dominant trait is not completely dominant, meaning for heterozygous the recessive trait is partially expressed
A disorder is X linked dominant. The father has the disorder and the mother is heterozygous. What chance do the sons and daughter have for the disorder
sons- 50%. they get 1 X from the mom so it depends on if the get the dominant or recessive X
daughter- 100%. Since the father only has 1 X which is the dominant one, all the daughters will have the disorder. They have a 50-50 chance of being homozygous for it vs carriers because of the mother being a carrier
What chromosomes does someone with turner syndrome have
What enzyme makes the DNA during DNA replication
the 3 letter code on the mRNA is known as? what is the start one?
DNA polymerase
codon, AUG
If you cross a Gg plant with a Gg plant (G-green, g=yellow), what percentage of offspring are expected to be green. What percentage will be heterozygous?
75% green
50% heterozygous
What inheritance pattern has 2 trait that are dominant
codominance
Mistakes in chromosome number are most commonly due to
nondisjunction
What is X inactivation
for those with multiple X chromosomes, only 1 is used and the other turn off (inavtivate)
In what site of the ribosome is the peptide bond made during translation
when will E. coli express its lac operon
P site
when lactose is present
You know that blue flowers is dominant for a plant species. You see a plant of that species with blue flowers. What is its genotype
you cannot determine the genotype just based of the dominant phenotype (they could be BB or Bb)
multiple genes control 1 overall trait. For example skin color is controlled by a variety of genes
explain nondisjunction
during meiosis the chromosomes do not separate evenly so 1 cell has more and 1 cells has less chromosomes
explain the chromosome mutation translocation
a part of one chromosome breaks off and attaches to a different chromosome
What happens to DNA if it mutates
Do all mutations lead to cancer
the sequence of nucleotides has changed
no, only specific mutations