M&RLifeCyclesLEC5 Flashcards
Is interphase part of Mitosis, or Meiosis?
Neither! Both of then start with Prophrase.
So what is meiosis?
When diploid somatic cells are divided up, and turn into haploid gametes. This takes place in the gonads!
What separate during Meiosis I?
Homologous Pairs! Which are two chromosomes that control the same trait. One from mom, the other from dad.
What separate in Meiosis II?
Sister chromotids!
What helps gives us the variation that are seen among offspring?
Meiosis, and independant assortment!
Each pair of chromomes sorts into daughter cells (independently) of the other pairs. What is this process called?
Independent assortment!
During Metaphase I:
・Homologous pairs of chromosomes orient randomly.
・So as cell divison commences, they split up and shuffle. Like a square dance.
How many different siblings can a person have from the fusion of gametes?
It can produce zygotes with as many as 64 trillion different combination of genes.
What genetic variation contributes to evolution?
Mutations, and Sexual reproduction!
What are the original source of genetic variation?
Mutations!
What produces new combinations of genes, adding more diversity?
Sexual reproduction! Meiosis!
What is a visual representation of the chromosomes?
Karyotype!
Do other organisms also follow the human’s reproduction process?
No! They do it differently.
Ex: Honey bee males are haploid and females are diploid. The queen can choose to fertilized an egg or not.
What can lead to conditions like Down syndrome, which involves an extra copy of a chromosome?
Nondisjunction in Meiosis I! Incidence of down syndrome increases dramatically with age.
What is this called where one set of homologs does not separate?
Nondisjunction! This is what makes seedless watermelons.
