Bio Chapter 11-13: Exam 4

First step of cell division

Prophase- the cell prepares for division by condensing its DNA

Second step of cell division

Metaphase- chromosomes line up and spindle fibers attach

Third step of cell division

Anaphase- chromosomes are separated by spindle fibers pulling them apart

Fourth step of cell division

Telophase- chromosomes have arrived at opposite poles, and nuclear envelope forms

Prokaryotic cell division: what is it called?

binary fission (Asexual reproduction)

What are the steps of binary fission?

1. DNA replication

2. Cell growth

3. Septum formation (new cell wall and membrane grow in the middle)

4. Cell splitting

Which is simpler? Prokaryotic or Eukaryotic chromosomes?

Prokaryotic chromosomes

Where is the chromosome found in Eukaryotic cells?

the nucleus

Where is the chromosome found in Prokaryotic cells?

an irregularly shaped area called the nucleoid, not enclosed by a membrane.

Features of Prokaryotic Chromosomes

circular, one main chromosome, loosely packed

Features of Eukaryotic Chromosomes

linear, multiple chromosomes, tightly wrapped around histone proteins

What triggers reproduction in eukaryotic cells?

growth factors, hormones, and proper cell size or DNA integrity

What triggers reproduction in prokaryotic cells?

Environmental conditions (e.g., nutrients, temperature, cell size)

sister chromatids

two identical copies of a chromosome that are formed during DNA replication

homologous pairs

two chromosomes, one from each parent, that have the same size, shape, and genes in the same locations

mitosis

the process of cell division, where a single parent cell divides into two genetically identical daughter cells (babies/growth and repair)

somatic cells

any cell of a living organism other than the reproductive cells

meiosis

a type of cell division that reduces the chromosome number by half, producing four genetically distinct gametes (sperm & eggs)

gametes

Mature haploid male or female germ cell (ex. sperm eggs)

What does mitosis produce?

Mitosis makes 2 identical diploid body cells for growth and repair.

What does meiosis produce?

Meiosis makes 4 unique haploid sex cells for reproduction.

3 Broad stages of cell cycle

1. interphase (longest stage, DNA replication)

2. mitosis (cell's nucleus divides)

3. cytokinesis (physically splitting the cell into two identical daughter cells)

Haploid

One set of chromosomes (formed through meiosis) ex. Sperm and egg cells in humans

Diploid

Two sets of chromosomes, one inherited from each parent (formed through mitosis) ex. somatic cells

What are the 3 subphases of interphase?

G1, S, and G2

What happens during interphase?

the cell grows, replicates its DNA, and prepares for cell division

What happens in G1 interphase?

the cell grows, produces proteins and organelles, and carries out its normal functions to prepare for DNA replication and division

What happens in S interphase

cell replicates its DNA, creating an exact copy of each chromosome

What happens in G2 interphase

cell continues to grow, synthesizes proteins, and produces organelles in preparation for mitosis