Unit 8: DNA and cell division Flashcards
nucleotide
the subunit of DNA a sugar, phosphate, and a base
Where the DNA is in the cell
nucleus
chromosome
one DNA molecule tightly packaged
double helix
the shape of the two DNA strands when they wind around each other
gene
a piece of a DNA molecule / chromosome hundreds or thousands of nucleotides the information to build one protein
genome
the entire set of DNA inside the nucleus (for humans, 46 chromosomes)
karyotype
a medical test which looks at all your chromosomes to see if they look healthy
DNA replication
takes place in the nucleus builds new strands of DNA against the old strands
helicase
an enzyme which unwinds the DNA double helix
DNA polymerase
an enzyme which builds the new DNA strand against the old DNA strand
Cell cycle
The stages a cell goes through before dividing: G1, S, G2, M
interphase
the time in which the cell functions, grows, and builds new parts before dividing
prophase
the DNA condenses into chromosomes (X shaped) the nucleus dissolves the spindle starts to form
metaphase
The chromosomes line up at the cell’s equator the spindle is fully formed
anaphase
The spindle contracts, pulling apart the chromosomes. The sister chromatids move towards opposite ends of the cell.
telophase
Two nuclei begin to form, at opposite ends of the cell. The spindle starts to break down.
cytokinesis
the cell divides into two daughter cells
many chromosomes
the genome
the cell cycle
one chromosome
containing replicated DNA (2 sister chromatids)
A karyotype
diploid
Containing two complete sets of chromosomes, one from each parent.
A cell containing two complete sets of chromosomes, one from each parent.
diploid
All of our cells are diploid except for our eggs (or sperm in men).
Haploid
Having a single set of unpaired chromosomes.
Having a single set of unpaired chromosomes, which is a product of meiosis.
haploid (our eggs are haploid and sperm in men are haploid)
What do meiosis and mitosis have in common?
Both replicate cells. Both go through Interphase, Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis
What are the important differences between mitosis and meosis?
Meiosis makes eggs and sperm ( unique, haploid cells), while mitosis makes typical body cells (identical, diploid cells)
Mitosis is 1 division, Meiosis is 2 divisions
What is this image showing? How do you know?
This is Meiosis because it is cell division that produces 4 unique cells (gametes)
What is this image showing and how do you know?
Mitosis because it produces 2 identical cells
