Flashcards in Genetics Deck (21):
What are the four phases of Mitosis?
Prophase, Metaphase, Anaphase, Telophase
What is a sister chromatid?
two identical chromosomes joined at centromere
What are homologous pairs?
equivalent but non identical and don't come near each other during mitosis
What happens during prophase?
Chromosomes condense, nucleolus disappears, spindle and kinetochore fibers appear, and centriole pairs move to opposite ends of cell.
What happens during metaphase?
chromosomes line up at center of cell.
What happens during Anaphase?
Spindle fibers shorten and sister chromatid pairs are pulled apart. Cell elonges and cleavage furrow formed
What happens during telophase?
nuclear membrane forms around chromosomes at each end of cell, nucleolus becomes visible. Cell splits in two
How many reading frames does a chromosome have?
What are the three reading frames?
Centromere, promoter, and regions of replication
What are protooncogenes
normal versions of genes thatallow for regular growth patterns but can be converted to oncogenes
What is a locus?
Specific location of gene on chromosome
What are alleles?
different versions of gene
What is a heterozygote?
a person carrying two different alleles at a given locus
What is a homozygote?
individual carrying two identical alleles
What happens during Prophase I of Meiosis?
homologs pair and recombination occurs
What happens in Metaphase I of Meiosis?
Tetrads are aligned on metaphase plate
What happens during Anaphase I of Meiosis?
Homologs separate. Sister Chromatids stay together
Describe Telophase I of Meiosis
Two haploid cells are made. Each cell has single set of chromosomes which exist as sister chromatids
What is the purpose of Meiosis II?
Just to separate sister chromatids
When are sister chromatids not identical?