7-Science-Genetics Quiz-StudyGuide1 Flashcards
Trait
characteristic of an organism
Inherited trait
trait that is passed down from parents to offspring
acquired trait
a trait that is obtained or acquired during someone’s lifetime
asexual reproduction
one parent, creates clones (except mutations)
sexual reproduction
two parents, sperm and egg, genetic diversity
mutation
random change in DNA
fertilization
union of sperm and egg during sexual reproduction
breeding
deliberate breeding of two organisms
allele
a version of a gene, two passed down per trait
dominant
gene that will be expressed if present
recessive
gene that will be masked if paired with a dominant gene
homozygous
genotype with two of the same alleles
heterozygous
genotype with two different alleles
genotype
combination of two alleles
phenotype
physical trait that is expressed
Traits can be influenced by genes and the…
environment
two examples of traits:
at least two: hair or skin or eye color, muscles or a tan or a scar
With a larger sample size, variations…
increase with the amount of unique organisms
Three advantages of studying plants or other simple organisms for heredity instead of humans are…
at least three: short generation time; produce many offspring; easy to obtain and maintain; many observable traits; more ethical
Marfan syndrome affects the body’s…
connective tissue
Some signs of Marfan syndrome are…
a long face, near sight, tall, curved spine or chest bone, thin, disproportionately long limbs, loose or double joints
Marfan syndrome can/cannot be fought from another person because…
the syndrome is genetic, not infectious, and therefore can’t be spread to another person, except to offspring
Marfan syndrome is caused by…
a single gene change in chromosome 15
Advantages of asexual reproduction are…
that it is quicker and more efficient than sexual reproduction
that it doesn’t require a mate
Disadvantages of asexual reproduction are…
a lack of genetic variation
Advantages of sexual reproduction are…
that it provides genetic variation (offspring is never identical to parent).
Disadvantages of sexual reproduction are…
that it requires a mate
that it is slower and less efficient than asexual reproduction
Examples of asexual reproduction in multicellular organisms are…
at least two: Hydras- budding; Geraniums- cuttings; strawberries- runners; starfish- regeneration
What can cause offspring of asexual reproduction to have a trait different from the parent?
a mutation
Identical are more similar than fraternal twins because…
Identical twins are from one zygote that split (identical DNA)
Fraternal twins are from two different zygotes (as similar as normal siblings)
Breeding is preformed to…
produce desired traits
increase an endangered population (maintain a species)
study genetics
The Rules of Inheritance are…
offspring receives equal DNA from both parents
offspring gets one gene per characteristic per parent
some genes are dominant and will be expressed
How could a recessive trait appear in 25% of the offspring when both parents have the dominant trait?
in this case, the parents must have been heterozygous for the dominant trait, meaning that there would be a 25% change for a offspring to get a recessive allele from both parents.
Blue tail color is dominant to orange tail color, which means…
Blue tail color will be expressed if the allele for it is present
In the breeding model between two heterozygous parents, the offspring or results were not exactly 3:1 because…
our sample size was too small
Mendel studied more than one characteristic in pea plants to…
make sure that his rules applied to all situations
What are the traits for pea seed color?
A good set of letters for the alleles would be…
Because…
Green and Yellow
Y and y
Yellow is dominant
Offspring cannot have a recessive trait if one parent is homozygous for a dominant trait because…
every offspring would get at least one dominant allele from that parent
