Chapter 2

Question 1

Prokaryotes

Answer 1

archaic, has a cell wall, plasma membrane and ribosomes

some DNA don’t have genes arranged in chromosomes, they go thru binary fission

cells do not contain a membrane-bound nucleus

have singular circular chromosome

Question 2

Eukaryotes

Answer 2

Have nuclear DNA, go thru mitosis and sometimes meiosis

focus primarily on animal genetics

DNA is complexed with histone proteins to form chromatin

multiple, linear chromosomes within nucleus

Question 3

The Cell Cycle

Answer 3

stages in the life of a cell

Question 4

Mitosis

Answer 4

asexual reproduction - produces genetically identical daughter cells

prophase
prometaphase
metaphase
anaphase
telophase

Question 5

Meiosis

Answer 5

produces haploid gametes

I - reduction (produces 2 haploid cells)
II - equational (produces 4 haploid cells)

Question 6

Gametogenesis

Answer 6

processes of creating a sperm or an egg

sperm - generic meiosis and creates 4 sperm cells at the tend

egg - meiosis but doesn’t make 4 unique things at the end due to the size of eggs needing to be big, the go through cannobilizing the cytoplasm of the other “eggs”. 1 egg cell at the end is viable

Question 7

How do histones and chromatin impact gene expression?

Answer 7

DNA of eukaryotic cells are complexed with histone to form a chromatin

they must be compact enough to fit in the nucleus, and this limits the accessibility of DNA to proteins in terms of RNA polymerase

gene expression in the cell is dependent on how tightly the DNA is bound to the histones

Question 8

Understand the difference between chromosomes and chromatids and be able to track each through mitosis and meiosis.

Answer 8

duplicated chromosome consists of 2 sister chromatids

mitosis:
prophase - each chromosome contains 2 chromatids
anaphase - chromatids separated

meiosis I:
diploid to haploid (1 -> 2)

meiosis II:
haploid to haploid (2 -> 4)

Question 9

Be able to recognize descriptions and diagrams of all stages of mitosis and meiosis

Answer 9

Mitosis:
Prophase - chromosomes condense. each chromosomes posses two chromatids. The mitotic spindle forms
Prometaphase - the nuclear membrane disintegrates. Spindle microtubules attach to chromatids
Metaphase - chromosomes line up on the metaphase plate
Anaphase - sister chromatids separate and move toward opposite poles
Telophase - chromosomes arrive at spindle poles. The nuclear membrane re-forms and the chromosomes relax

Meiosis I: same as mitosis but 2 major differences. you have 2 x’s that are join together and you have full x’s being pulled together

late prophase I and metaphase I: chiasmata leads to crossing over, the actual shuffling up phase, this is where you make sure each daughter cell is unique

Meiosis II: same as mitosis