Mitosis
What type of reproduction is mitosis
asexual
What is the goal of meiosis?
create four genetically unique cells (gametes)
True or False: Mutations can lead to genetic variation.
true
What stage is considered the "resting phase"
G0
What connects to chromosomes together?
Centromere
What is the phase called that includes mitosis and cytokinesis?
m phase
What is special about Prophase I?
crossing over
What is the most common cause of genetic variation?
Sexual reproduction
What phase is DNA reduplicated in?
S phase
What is cellular senescene?
- Irreversible loss of the ability
to divide
- Response to DNA damage
- Alternative to apoptosis
- Related to changes associated with aging
What gets separated in anaphase?
sister chromatids
What gets pulled apart in Anaphase I?
Homologous chromosomes (have to say homologous for it to be correct!)
What is the change in the structure and or number of chromosomes in a cell?
Chromosomal aberrations
What is chromatin
loosely packed DNA
Brown eyes- B
Blue eyes- b
parent 1: Bb parent 2: BB
What are the chances of the offspring having blue eyes?
0%
What is the goal of mitosis
two genetically IDENTICAL daughter cells
How many chromosomes are in the final product gametes of meiosis? AND what are these specific cells called?
23 & haploid (must get both for full credit)
what is crossing over?
the exchange of genetic information in prophase I
True or False: The cell spends most of its time in mitosis.
False - interphase!
What did Mendel's study prove?
That offspring carry the same genotypes as parents even if they are not always expressed.
Describe the main events that occur during anaphase of mitosis. How does this phase contribute to the equal distribution of genetic material between the two daughter cells?
Separation of sister chromatids: The sister chromatids, which were previously held together at the centromere, are separated when the centromere splits. Each chromatid is now considered an individual chromosome.
Movement toward opposite poles: The separated chromatids (now individual chromosomes) are pulled toward opposite poles of the cell. This movement is facilitated by the spindle fibers (microtubules), which shorten and pull the chromosomes toward the centrosomes at each pole.
Ensuring equal distribution: As the chromosomes are pulled apart, the genetic material is evenly distributed between the two sides of the cell. This ensures that each daughter cell will receive an identical set of chromosomes.
Contribution to equal distribution: Anaphase is crucial for ensuring that each daughter cell ends up with the correct number of chromosomes. The separation and movement of sister chromatids ensure that both daughter cells receive an exact copy of the genetic material from the parent cell, contributing to the maintenance of genetic stability.
Describe the difference between meiosis I and meiosis II. How does each division contribute to the formation of genetically diverse gametes?
Meiosis consists of two divisions: Meiosis I and Meiosis II. In Meiosis I, homologous chromosomes are separated, reducing the chromosome number by half, and genetic diversity is introduced through crossing over (exchange of genetic material between homologous chromosomes) and independent assortment (random distribution of chromosomes). In Meiosis II, which resembles mitosis, the sister chromatids of each chromosome are separated into four haploid gametes. While Meiosis II doesn't directly contribute new genetic variation, it ensures that each gamete contains one copy of each chromosome. Together, these processes create genetically diverse gametes, which, when combined during fertilization, lead to offspring with unique genetic combinations.
List the three most common causes of genetic variation (MUST GET ALL 3)
-independent assortment
-crossing over
-random fertilization
What stage is the final stage of interphase? AND what is the purpose of this stage?
G2
further prepare for division by ensuring proper growth and nutrients are present in the cell as well as check for mutations in the DNA
_____ is when characteristics of both parents mix together to create their offspring.
incomplete dominance
Why not blending?