Genetics Flashcards
Does meiosis or mitosis have PMAT I and PMAT II
Meiosis
Does a cell go back into G1 phase in meiosis like it does in mitosis?
No, the cycle ends at telophase II.
What are homologous chromosomes?
Same genes, same order but different alleles (comes from different parents)
What is the goal of meiosis I?
To separate homologous pairs
What is synapsis in prophase I?
Pairing up of homologous chromosomes
What are the two thing that happen in meiosis I that does not in mitosis?
1) synapsis - pairing of homologous chromosomes
2) crossing over - DNA exchange
What happens in metaphase I?
The tetrads are aligned at cell center
What are tetrads?
Four chromosomes (2 homologous pairs that have sister chromatids attached to each of them)
What happens in anaphase I?
1) Pull homologous pairs apart into different poles
2) Start cytokinesis
What happens in telophase I?
1) Reverse mitotic prophase (eggs do it but not sperm)
2) Finish cytokinesis
Which part (I or II) of meiosis the same as mitosis?
Meiosis II
What is nondisjunction?
The failure to properly separate DNA during gamete formation (meiosis)
How can you tell a nondisjunction in anaphase I vs anaphase II
Anaphase I failure would lead to four abnormal cells at the end
Anaphase II failure would lead to two abnormal cells at the end
What is a trait that comes with many forms (hair color)?
Polymorphic trait
What is a version of a gene?
Allele
What is a trait determined by many genes (height)?
Polygenic trait
What is classical dominance (genetics)?
When one allele is dominant and another one is silent.
What is incomplete dominance (genetics)?
When a new phenotype is seen by a heterozygous due to both the dominant and recessive allele playing a role.
Eg: flower colors (pink flower from red and white)
What is codominance (genetics)?
When the two traits are both seen in the phenotype at the same time.
Eg: blood type (A, B or AB)
What is epistasis?
Dominance between different genes and not between different alleles of the same gene.
Eg: albino gene prevents the expression of pigment genes. Albinos have the pigment gene, it is just suppressed.
Is Rh factor an example of classical dominance?
Yes it is.
Eg: IaiRr = type A+, iiRR = type O+
What is transfusion reactions?
The immune system reacting to foreign proteins due to the wrong type of blood type being transfused to a person.
What is the universal donor?
Type O-
What is the universal recipient?
Type AB+
