Mitosis + Meiosis Flashcards
Somatic vs. Gametes
Somatic cells are diploid—meaning they have two sets of chromosomes. Gametes are haploids—meaning that have only one set of chromosomes.
somatic vs gametes cells
Somatic cells are body cells. Gametes are sex cells.
What are all stages of mitosis?
Gap 1, synthesis, gap 2, prophase, metaphase, anaphase, telophase, cytokinesis
What is a chromatin?
Loose/unraveled DNA
What is a chromatid?
A newly copied condensed chromosome
What is a chromosome
Two condensed chromatids joined by a centromere
What is a centromere
The center of the chromosome where the chromatids connect
What are spindle fibers made up of?
Tubulin
What are the phases of interphase?
Gap 1, synthesis, gap 2
What happens in gap 1
Cell grows in size. Organelles replicate.
What happens in synthesis?
Replication of DNA. synthesis of proteins associated with DNA
What happens in gap 2?
Synthesis of proteins associated with mitosis
What happens in prophase?
Chromatin condense into chromatids. Spindle fibers form. Chromosomes are captured by the spindles. Nucleolus breaks down.
What are spindle fibers?
Specialized microtubules radiating out from centrioles.
What happens in metaphase?
Chromosomes align along the equator of the cell, with one chromatid facing each pole.
What happens in anaphase?
Spindle fibers shorten and pull chromatids towards opposite poles. Sister chromatids separate to opposite poles.
What happens in telophase?
Spindle fibers disintegrate. Nuclear envelopes form around both groups of chromosomes. Chromosomes revert to chromatid. Cytokinesis occurs.
What is cytokinesis?
Splitting the cytoplasm.
What is mitosis?
The splitting of the nucleus.
Difference of cytokinesis and mitosis
Mitosis is the splitting of the nucleus. Cytokinesis is the splitting of cytoplasm.
What is cleavage furrow?
When animal cells go through cytokinesis.
What is cell plate?
Happens in plant cells when undergoing cytokinesis.
Do plant cells have centrioles?
NO YOU DIMBAT
What organisms go through meiosis?
All sexually producing animals.
Where does meiosis take place? Differentiate between males and females.
Males - tetes, females - ovaries
Why does meiosis happen?
To produce offspring with a combination of genes from both parents. It allows unique offspring.
What are homologous chromosomes?
Similar in size, shape, position of the genetic information. Not identical.
What are the two types of chromosomes from each parent?
One paternal chromosome, one maternal chromosome. Sister chromatids of each.
Paternal vs maternal
Paternal is from a father. Maternal is from a mother.
What is a tetrad?
2 sets of homologous chromosomes connected by a centromere.
Why is crossing over important?
Introduces genetic variety.
When does crossing over happen?
Happens in prophase 1.
What happens in crossing over?
Homologous chromosomes exchange genetic info and produce recombinant chromatids.
What is chiasmata?
The exchange of genetic information from homologous chromosomes.
What is the order in meiosis?
Interphase, prophase 1, metaphase 1, anaphase 1, telophase 1 + cytokinesis, prophase 2, metaphase 2, anaphase 2, telophase 2 + cytokinesis.
How many daughter cells in mitosis vs meiosis?
Mitosis makes 2. Meiosis makes 4.
What are checkpoints used for?
To check that cell division is following through correctly. During these checkpoints, mistakes can be corrected or the cell can be stopped from going through division.
What are the three different checkpoints?
G1/S checkpoint. G2/M (mitosis) checkpoint, spindle checkpoint.
What is the G1/S Checkpoint?
First checkpoint. Decides if a cell will continue through cell division.
What is the G2/M checkpoint?
Checks if a cell went though all stages of interphase correctly. Let’s a cell go through mitosis.
What is the spindle checkpoint?
Checks that all chromosomes have attacked to the spindle for anaphase.
What allows cells to continue cell division?
Growth factors. Size of the cell. Nutritional intake
What is the average cell division for animals?
10-20 hours
