genetics reveiw Flashcards
take dat test
what name did Mendel give to the characteristic that seemingly disappeared from the generation?
recessive
A gene exists in two different forms (A and a). With respect to the allele present, which type of gamete can a homozygous recessive individual produce?
a
The gene makeup of an organism for a particular trait is its:
genotype
The physical appearance of an organism for a particular trait is its
phenotype
in the cross of Tt x Tt,
the proportion of the offspring that will have the same genotype as the parents is
50%
If an organism of genotype AA
mates with an organism of genotype Aa and 150 offspring are produced, the number of offspring with genotype Aa will most probably be close to:
70
Two parents were known to be right-handed. Assuming that right-handed (R) is dominant to left-handed (r), what would be the genotypes of the parents if their son is left-handed
Rr x Rr
The alleles for blood types A and B are codominant but are dominant over the allele for blood type O. Answer the following question. A female with AB blood type and a male with O blood type have several children. The phenotypic ratio for these children would be:
1/2 type A and 1/2 type B
I^i represents the blood group phenotype.
A
If a human zygote has an X and a Y chromosome, it will normally produce a:
male
A man with red-green colour blindness marries a woman who has normal colour vision and is not a carrier of the gene for this trait. Which of the following statements would best describe their offspring?
no children will be colourblind but daughters will be carriers
color blindness is a sex-linked characteristic because the gene is
carried on a sex chromosome
the rare trait called ocular albinism, an almost complete absence of I pigment, is inherited as a sex-linked recessive trait. If a man with the condition marries a woman who is a carrier of this condition, their offspring will result..
about half the sons and half the daughters will have ocular albinism the other half will just be carriers
a man is a hemophiliac, this indicates that he:
inherited the condition from his mother
an x-linked dominant allele is inherited from a heterozygous female
equally male and female
what is the law of segregation
the separation of paired alleles during meiosis
what is the law of independent assortment
If genes are located on separate chromosomes, they are inherited independently of each other.
what are hybrids
offspring that differ in one or more traits
genes are….
a unit of instruction located on a chromosome, which produces or influences a specific trait in the offspring.
recessive
alleles of this type are overruled when the genotype is not homozygous
inheritance is..
the process of recciving traits from previous generations
what are alleles
two or more alternate forms of a gene
dominant alleles determine the
determine the expression of the genetic trait
a phenotype is..
a type of cross that involves two genes, each consisting of nonidentical alleles.
a Punnett square is
a chart used by geneticists to show the possible combinations of alleles in offspring
a genotype is
the alleles an organism contains
alleles are…
two or more alternate forms of a gene
homozygous is…
a genotype in which both alleles of a pair are the same
what is a monohybrid cross
a cross that involves one allele pair of contrasting traits
heterozygous is
a genotype in which the alleles of a pair are different
a phenotype is
the observable traits of an organism
recessive lethal is
A small, dark spot of chromatin located in the nucleus of a female mammalian cell
mutation means
a heritable change in the molecular structure of DNA
haemophilia is
an example of a sex-linked trait
XX refers to
female sex chromosomes
XY refers to
male sex chromosomes
somatic means
all the cells of an organism other than sex cells
As a result of a mutation, the allele for hemophilia is believed to have been present in Queen Victoria. Hemophilia is a sex-linked trait that affects males more often than females. Leopold, Duke of Albany, one of Victoria’s children, was a hemophiliac. He had two children, one male and one female.
the probability that has brother was also a hemophiliac
If a normal man marries a normal woman whose father was colourblind, what are the chances that their sons and daughters will be colourblind? Colourblindness is a sex-linked trait that affects males more often than females.
their sons will have a high chance of being color blind while their daughter is will be unaffected but be carriers
