Genetics
___ is the scientific study of heredity and variation
What is genetics?
The first diploid cell is called
Stage of mitosis in which the chromosomes are aligned at the center of the cell is called
What is metaphase?
Describe random fertilization
What is adds to genetic variation because any sperm can fuse with any ovum (unfertilized egg
Chromosomes are not...
What is cells?
The union of gametes is called __ and results in a ___.
What is fertilization and zygote
These cytoskeletal elements form the cleavage furrow in animal cells
What is microfilaments?
Crossing over begins as early as
__ is an ordered display of the pairs of chromosomes from a cell
What is karyotype?
The three main types of sexual life cycles differ in the timing of
What are meiosis, fertilization and mitosis?
Cells that receive signals from within the cell are called
What is endogenous?
Crossing over creates ____
What is recombinant chromosomes?
Human somatic cells have ____ pairs of chromosome
23
The phase of meiosis in which crossing over is called
What is prophase 1?
Prokaryotic cells cannot undergo?
What is mitosis
These three events are unique to meiosis and occur in meiosis 1
What is
1)synapsis and crossing over in prophase I
2) At metaphase I à paired homologous chromosomes (tetrads)
3) At anaphase I, homologous chromosomes, NOT sister chromatids, separate
Three mechanisms that contribute to genetic variation
What is crossing over; independent assortment of chromosomes; random fertilization
At what stage is a cell haploid
In binary fission, the chromosome replicates beginning at the ___?
What is origin of replication
Describe independent assortment
What is each pair of chromosomes sorts maternal and paternal homologues into daughter cells independently of the other pairs?