Meiosis 1 and Meiosis 2
How many cells are created after Meiosis 1.
2 cells
What does heterozygous mean?
different
Define the word genotype.
The letters when doing a punnett Square.
(Gg, gg, GG)
In humans, free earlobes (E) are dominant over attached earlobes (e). A person has attached earlobes. This must be their genotype.
ee
The chart used to track the inheritance of traits through generations of a family.
Pedigree
4 cells
What does homozygous mean?
the same.
An allele that is only expressed when two copies are present.
An organism that carries one dominant allele and one recessive allele for a trait but shows the dominant phenotype.
A carrier.
A fully shaded symbol in a pedigree usually represents this.
An affected person.
Define what happens during Telophase in Meiosis 1 and 2.
In Meiosis 1 there are 2 new cells created in Meiosis 2 there are 4 new cells created.
In pea plants, purple flowers (P) are dominant over white flowers (p). A heterozygous purple plant (Pp) is crossed with a white plant (pp). This is the expected phenotypic ratio of the offspring.
50% purple, 50% white
The observable trait of a person is called what?
Phenotype
In pea plants, yellow seeds (Y) are dominant over green seeds (y). This is the phenotype of a plant with the genotype Yy.
If two unaffected parents have an affected child, the trait is most likely inherited in this way.
It is recessive
Define what happens in anaphase.
Chromosomes separate and head towards the poles.
If both parents are heterozygous (Aa × Aa), this is the probability of producing a homozygous recessive offspring.
25% chance or 1 out of 4.
An allele that is expressed whenever it is present.
Two purple-flowered plants produce some white-flowered offspring. This must be the genotype of both purple parents if purple (P) is dominant.
Pp and Pp
If an affected father passes a trait to all of his daughters but none of his sons, the trait is most likely inherited in this way.
It is most likely x-linked
Define what happens during Metaphase.
Chromosomes line up in the middle at the equator.
If a heterozygous tall plant (Tt) is crossed with a short plant (tt), this percentage of offspring is expected to be tall.
50% chance
The type of cell division that produces gametes with half the number of chromosomes.
Meiosis
A child shows a recessive phenotype, but both parents show the dominant phenotype. This must be true about both parents’ genotypes.
Both parents are heterozygous
A woman who is a carrier for an X-linked recessive disorder has this probability of passing the disorder to her sons.
50% chance