Flashcards in Week 6 Deck (61)
Name the two categories of cells found in multicellular animals:
Reproductive cells (found in ovaries & testicles; divide via meiosis)
Somatic cells (all other cells in body; divide via mitosis)
Interphase, Prophase, Metaphase, Anaphase, Telophase (PMAT is the mitotic phase)
What's the first phase?
Interphase (also known as the resting phase)
- during Interphase, DNA is unwound, so it can replicate
Interphase contains three phases, what are they?
G1 (Growth phase)
G2 (Growth & final prep for division)
- maturing, just divided; has a lot of metabolic activity; it's growing; can double in size
- replicates its DNA
Growth and final prep for division
- brief; getting ready to divide (we need enzymes & proteins); centrioles are ready now/fully grown
Nuclear envelope is breaking down
Now we can see our DNA as the chromatin coils and condenses to form barlike chromosomes.
Composed of two identical chromatids that are linked together in the middle, known as the centromere or kinetochore.
All chromosomes line up in what's called the metaphase plate. The centrioles have to polarize at opposite ends of the cell.
The chromatids are pulled apart.
Each chromatid becomes its own chromosome.
Shortest phase of mitosis.
It's the final stage of mitosis.
Chromosomes begin to unravel, elongate, and return to diffuse into chromatin.
A nuclear envelope appears around each new set of chromosomes and nucleoli appear in each nucleus.
Ultimately, cell pinches itself in half; forming two completely separate daughter cells.
Cytokinesis (cytoplasmic division) marks the end of telophase. Now the daughter cells will enter interphase and the cycle starts all over.
A full set of chromosomes (interphase)
unwound DNA (threadlike)
identical sister in a chromosome
Reproduction goes through ...
all the same phases (Prophase, Metaphase, Anaphase, Telophase)
Goes through two stages: Meiosis I & II
Most influental phase in Meiosis
Chromosomes set up in pairs, called a Tetrad.
When they set up in pairs like that, they touch in certain places and even CROSS OVER.
Crossing over = Synapsis
Lining up of the pairs on the metaphase plate
Pulling apart the tetrad
Cell splits in two with same number of chromosomes in each cell.
Now we move onto Meiosis II
The two cells are not identical as in Mitosis. They have exchanged genetic material.
All chromosomes line up on metaphase plate in each cell.
The chromosomes are now pulling apart (as they did in Mitosis' Anaphase)
The cells split in half, leaving us with four cells now, also known as gametes or sex cells.
What are macromolecules?
Long, complex molecules, often with repeating units.
Carbohydrates, lipids, proteins, nucleic acids
Carbs can be ...
Simple or complex sugars
They are composed of carbon, hydrogen and oxygen
Hydrated carbon or water-containing carbon
Glucose is ...
A monosacchride (one sugar)
It has six carbon atoms and is known as a hexose sugar
What are dissachrides?
Two sugars (table sugar is a dissacchride or sucrose
What three elements are found in all carbs?
Carbon, Hydrogen and Oxygen