Biology Chapter 8 Review

Both Mitosis and Meiosis are preceded by what?

Interphase

Review Key Terms.

Notes

What occurs during interphase?

- cell's metabolic activity is very high and the cell performs its various functions - a cells makes more cytoplasm - it increases its supply of proteins, creates more cytoplasmic organelles, and grows in size

What is the difference between asexual and sexual reproduction?

Asexual- the creation of genetically identical offspring by a single parent, without the participation of sperm and egg. Sexual- requires fertilization of an egg by sperm.

What is binary fission (prokaryotic) and cytokinesis (eukaryotic)?

Binary fission- the process by which prokaryotes reproduce asexually Cytokinesis- division of cytoplasm, produces two genetically identical daughter cells

Concerning chromosomes, what is "deletion"? What is "duplication"? What is "inversion"? What is a "translocation"?

Deletion- a segment of a chromosome is removed (most harmful) Duplication- a segment of a chromosome is copied and inserted into the homologous chromosome Inversion- a segment of a chromosome is removed and then reinserted "backward" to its original orientation (least harmful) Translocation- segments of two non homologous chromosomes swap locations with each other

Review terms diploid and haploid as they apply to mitosis and meiosis.

Diploid- a cell containing two homologous sets of chromosomes, one set inherited from each parent; a 2n cell Haploid- a cell containing a single set of chromosome; an n cell

Eukaryotic cells spend most of their cell cycle in what phase?

Interphase

Compare prokaryotic and eukaryotic complexities.

Prokaryotic- binary fission (prokaryotes, bacteria and archaea, reproduce), smaller, distributing the copies equally to two daughter bacteria is still a formidable task. Eukaryotic- more complex, larger, have more genes, genes are found in the nucleus.

How do eukaryotic and prokaryotic chromosomes differ?

Prokaryotic- smaller chromosomes, difficult to divide the chromosomes up evenly. Eukaryotic- chromosomes found in the nucleus, number of chromosomes depends on the species, contain protein, which help maintain the chromosome's structure and control the activity of its genes, chromosomes are duplicated and divided before the cell divides.

During which stage of meiosis does synapsis and the formation of tetrads occur?

Prophase I- homologous chromosomes each composed of two sister chromatids, come together as pairs

Review the "cell cycle control system", how does it work? What is happening when cells seem to fail to exhibit density-dependent inhibition?

a cyclically operating set of molecules in the cell cycle, a checkpoint in the cell cycle is a critical control point where stop and go-ahead signals can regulate the cell cycle

Review density-dependent inhibition. What is it?

a phenomenon in which crowded cells stop dividing

What is a karyotype?

an ordered display of magnified images of an individual's chromosomes arranged in pairs

What is a special feature to plant mitosis, as compared to animal mitosis?

cell wall

Review interphase. What genetic material is duplicated? When does the cell grow/synthesize materials?

chromosomes, G₁, S, G₂- the cell grows S- DNA synthesis

When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of what?

density-dependent inhibition

What is a sister chromatid? What does it look like on a chromosome (where do sister chromatids attach?)

each chromosome consists of two copies, they are attached at the center (centromere)

"Like begets like" refers to what?

the ability of organisms to reproduce their own kind (this is the one characteristic that best distinguishes living things from nonliving matter)

What is "Nondisjunction"?

the members of a chromosome pair fail to separate

What is special about human nerve cells and muscle cells?

they don't need to be replaced as often as other cells

Cancer is NOT usually inherited because...?

we get our DNA from sperm and egg cells, cancer often happens because of a DNA accident in a cell other than an egg or a sperm, it is not passed down.