Scribd
Upload
4 views5 pages

Bio Finals

The document covers key concepts of cell biology, including chromosomes, chromatids, diploid and haploid cells, and the cell cycle phases (G1, S, G2, M, and G0). It details the processes of mitosis and meiosis, including their phases and checkpoints that ensure proper cell division. Additionally, it highlights the importance of genetic variation through recombination and crossing over during meiosis.

Uploaded by

Mardie Ramos
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
4 views5 pages

Bio Finals

The document covers key concepts of cell biology, including chromosomes, chromatids, diploid and haploid cells, and the cell cycle phases (G1, S, G2, M, and G0). It details the processes of mitosis and meiosis, including their phases and checkpoints that ensure proper cell division. Additionally, it highlights the importance of genetic variation through recombination and crossing over during meiosis.

Uploaded by

Mardie Ramos
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 5

Lesson 1:

Chromosome

- Threadlike
- Nucleic acids & proteins
- Found in nucleus
- Carries genetic info

Chromatid

- Divided chromosome

*Dot in the middle of chromatids is called a centromere

Diploid

- Paired/two sets of chromosomes, one from each parent

Haploid

- AKA Monoploid
- 1 chromosome copy

Cell Cycle

- Growing and division of cells

PHASES

G1

- Cell grows
- Organelles get copied

- Synthesizes DNA copy in nucleus


- Duplicates centrosome (microtubule-organizing structure)

G2

- Cell grows more


- Cell organizes contents
- Mitotic(M) Phase
- Cell divides DNA and cytoplasm to make two new cells
- Mitosis
- DNA condenses into chromosomes that is pulled apart by mitotic spindle
- Prophase = DNA -> Chromosomes
- Metaphase = Chromosomes arrange at middle and attach to centrosome
- Anaphase = Chromosomes split apart
- Telophase = New nuclear envelope forms
- Cytokinesis
- Cell splits apart

G0

- Cell not preparing to divide


- Could be permanent for some cells

Cell Cycle Checkpoints

-Checks if cellular activities are complete

G1 Checkpoint

- Size (is it big enough?)


- Nutrients (Does it have enough energy?)
- DNA integrity (Is DNA damaged?)
- Molecular signals (Was it told to divide?)
- If the conditions are not met, the cell will enter G0

G2 Checkpoint

- DNA integrity (Is DNA damaged?)


- DNA replication (Was DNA replicated?)
- If the conditions are not met, the cell will repair itself. IF cell damage is irreparable, APOPTOSIS
(death)

Metaphase/Spindle Checkpoint

- Are chromosomes attached to spindle fibers?


- If the conditions are not met, the cell will repair itself.
Lesson 2:

Cell division

Mitosis

- Two daughter cells (Genetically identical)


- Eukaryotes use this, except germline cells (they use meiosis to produce gametes [eggs and
sperm])

Meiosis

- Single cell divides twice to make 4 cells that have half the genetic info (sex cells)

PHASES

Meiosis I

1. Interphase
- Preparing for division
2. Prophase I
- Exchanging bits of DNA through recombination/crossing over
- Recombination
- Recombining genes to produce different gene variations
- Crossing Over
- AKA Chromosomal Crossover
- DNA exchange between chromatids
- Point of attachment = chiasma
3. Metaphase I
- Chromosomes line up in pairs and attach to spindle fibers
4. Anaphase I
- Pair is split
5. Telophase I and cytokinesis
- Chromosomes move to opposite poles
Meiosis II

6. Prophase II
-Two daughter cells

7. Metaphase II
- Chromosomes line up and attach to spindle fibers
8. Anaphase II
- Chromatids are split
9. Telophase II and cytokinesis
- Same as telophase in mitosis but theres two of em
Not enough caffeine in me to write all of that out

You might also like