Cells and Cell Division Flashcards
What are cells constructed from?
Four macromolecules: carbs, proteins, lipids, nucleic acid
What is the basic structural and functional unit in all organisms?
Cells
All cells are the same structurally.
False. All cells are structurally similar but not the same.
where is the genetic information of an organism stored?
in the nucleus
what is the function of the endoplasmic reticulum?
protein synthesis
golgi complex
packaging and transport of different products
mitochondria
produces energy for the cells
centrioles
important for cell division. helps chromosomes divide.
what is molecular identity?
helps body identify the cell/organize body
what is the function of the smooth ER?
lipid and steroid synthesis and carbohydrate metabolism
what happens to the body if the lysosome isn’t working?
Then the body wouldn’t receive fuel/food; therefore, degradation would occur.
interphase
- longest phase
- recovery period where the focus is on growing
what is mitosis and it’s stages?
division of the nucleus and segregation of chromosomes into future daughter cells.
- prophase
- metaphase
- anaphase
- telophase
when are chromosomes replicated?
during interphase (S phase)
What are sister chromatids are joined by?
They are joined by a common centromere and each carry identical genetic info
Prophase
- Chromosomes condense and become visible
- Nuclear envelope disappears
- Centrioles divide and migrate to opp poles
- Sister chromatids joined at centromere
- Spindle fibers form and attach to centromeres.
Metaphase
- Chromosomes move to the middle of cell
- Line up along the metaphase plate
Anaphase
- Centromeres split as sister chromatids are pulled to opp poles
- Sister chromatids are identical meaning that both daughter cells receive identical genetic info
Telophase
- Chromosomes of the daughter cells decondense
- nuclei reform in daughter cells
- end of mitosis
How does cytokinesis divide the cytoplasm?
The cleavage furrow divides the cytoplasm equally into 2 daughter cells (identical).
What is mitosis essential for?
For growth and cell replacement.
How does a cancerous tumor form?
When cells escape from the cell cycle regulation and grow uncontrollably.
What is progeria and it’s effects?
Children the age of 7 or 8 look 70. Cells aren’t going through the cell cycle quickly enough and affected individuals usually die of coronary heart disease in their teens.
What are the 2 types of cells in meiosis?
Somatic cells: In G0 or actively going through mitosis
Germ cells: become incorporated into reproductive organs
what is meiosis?
It produces 4 haploid cells containing only one copy of each chromosome.
why is halving essential?
to produce eggs/sperms & for transmission of genetic info to the next generation.
how are interphases alike for mitosis and meiosis?
chromosomes replicate in both.
How are the rounds of division for meiosis different?
Meiosis 1 separates homologous chromosomes (diploid > haploid). Meiosis 2 separates the sister chromatids.
How does the metaphase differ for meiosis and mitosis?
In mitosis, the chromatids line up randomly and do not pair with homologue. In meiosis, the chromatids stick together to ensure that the chromosomes divide the way you want them to.
what is interkinesis?
no DNA reply audio between the two nuclear division.
What are the two genetic variation of meiosis?
- Crossing over/recombination
- in prophase 1, exchange genetic info by breaking and reforming with a piece of non sister chromatid - Independent assortment
- number of chromosome combinations produced by independent assortment is 2^n
What are the 2 kinds of haploid sexual gametes formed by meiosis?
- Sperm
- Oocytes
Comparison of sperm and egg production
Sperm is continually produced from puberty until death while there is a finite number of oocytes. Four mature sperm in one spermatocyte while only one mature ovum from 1 oocyte.
