Chapter 9 Flashcards
Chromosomes in a karyotype can be characterized based on
size, shape, banding pattern
Trisomy 21 is more commonly known as
down syndrome
Familial genetic histories are displayed by a series of connected circles and squares called a
pedigree chart
Parents that appear normal but are capable of having a child with a genetic disorder are called
carriers
If both parents have the sickle-cell trait (are heterozygous), what is the chance of a child also having the sickle-cell trait (being heterozygous)?
50%
In snapdragons the allele R produces red flowers and allele W produces white flowers. The genotype RW produces pink flowers. Pure-breeding red-flowing snapdragons are crossed with pure-breeding white-flowering snapdragons. Calculate the proportion of snapdragons with pink flowers in the F1 generation.
100%
What human traits are a polygenic trait?
height, skin color, eye color
All of the offspring of a cross between a green-eyed Lurantis and a red-eyed Lurantis have green eyes. What is the expected phenotypic ratio of a cross between two red-eyed Lurantis
0 green-eyed: 1 red-eyed
Kevin’s parents have normal vision. however, Kevin has a inherited form of vision loss. His vision loss is a recessive trait that is associated with the abnormal allele v. The normal allele at this locus, associated with normal visions is V. Kevin’s parents could have which of the following genotypes?
Vv and Vv
Beak color in the Cramorant is controlled by a single gene. You mate a Cramorant homozygous for yellow (pigmented) beak with a Cramorant homozygous for white (unpigmented) beak and get numerous offspring all of which have a pale, white-yellow beak. This pattern of color expression is most likely to be an example of
incomplete dominance
In the lapra, a long neck (N), large eyes (L), long front flippers (F), and curled ears (C) are all dominant traits. What possible genotype could a long-necked, small-eyed, short front-flippered, curled-eared Lapras have
NnllffCC
Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as
true-breeding
Research since Mendel’s time has established that the law of segregation of genes during gamete formation
applies to all sexually reproducing organisms
Which of the following statements regarding genotypes and phenotypes is FALSE
A) alleles are alternate forms of a gene
B) an organism with two different alleles for a single trait is said to be homozygous for that trait
C) the genetic makeup of an organism constitutes its genotype
D) the expressed physical traits of an organism are called its phenotype
B, an organism with two different alleles for a single trait is said to be homozygous for that trait
What generation needs to be all heterozygous
F1
