BIO 101 Chapter 8 Obj jc

What is DNA Replication

The cell copies its DNA so each new cell gets a complete set of genetic instructions. Transcription > Translation > DNA Replication

What is meant by a semiconservative model of DNA replication

Each new DNA double helix has 1 old and 1 new strand

What are the functions of DNA helicase

Unwind the DNA, open up the double strand

What are the functions of DNA polymerase

Enzyme that makes new DNA strands

What are the functions of DNA ligase

Form bonds between DNA segments, binding them

What are the functions of binding proteins

Stabilize each strand

What are the functions of primase

Enzyme that adds primers

What are leading strands

Replication is continuous

What are lagging strands

Replication is discontinuous

What is a replication fork

Results from helicase splitting open a double strand

What are Okazaki fragments

Fragments created from the lagging strand

In which direction is DNA replication continuous

5’ to 3’

What are parent strands

Original DNA

What are daughter strands

New copy made from DNA

What is a replication “bubble”

Where DNA is being opened up to be copied

What is binary fission

How prokaryotes divide their cells

What are the four stages of binary fission of prokaryotes

Duplication, Elongation, Pinching/Deposition, Division

What is mitosis

Makes 2 identical body cells. Each new cell has the same number of chromosomes as the original

What is meiosis

Makes 4 unique haploid sex cells (sperm and eggs). Each new cell has half the number of chromosomes

What are functions of cell division

Growth, replace/repair cells, reproduction

What are reasons that chromosomes condense before cell division

To be easier to move and prevent tangling and less likely to break during cell division

What are histones

Proteins that DNA wraps around to stay organized and compact

What are nucleosomes

DNA wrapped around histones

What are centromeres

Middle point that joins chromatids

What is the cell cycle

Series of events a cell goes through to grow and divide into two identical daughter cells

What is interphase

G1, S, G2. Growth

What generally occurs during G1

Growth

What generally occurs during S

DNA Synthesis/DNA Replication

What generally occurs during G2

Growth, prepare for division

What is the difference between mitosis and cytokinesis

Mitosis, division of the nucleus
Cytokinesis, division of the cell itself

When does cytokinesis begin

After mitosis

What general events occur during prophase

Nucleus dissolve, chromosomes condense

What general events occur during prometaphase

How chromosomes are lined up towards the middle of the cell

What general events occur during metaphase

Chromosomes lined up, chromosomes are thickest

What general events occur during anaphase

Copies of chromosomes are pulled apart

What general events occur during telophase

Nucleus reforms, chromosomes decondense, two new nuclei form

What is the mitotic spindle and when does it form

fibers that move and separate chromosomes during cell division, forms in prophase

What are kinetochores

Attachment points for microtubules during cell division, help pull sister chromatids apart to opposite sides of the cell

How do animal cells undergo cytokinesis?

A cleavage furrow (pinch) forms as the cell membrane pulls inward. The cytoplasm splits in two, forming two new cells

How do plant cells undergo cytokinesis?

A cell plate forms in the middle of the cell because the cell wall is too rigid to pinch. The cell plate grows into a new cell wall that separates the two cells

What is cleavage

The process of splitting the cytoplasm during cytokinesis in animal cells

What is cleavage furrow

The indent or pinch that forms in the cell membrane during cytokinesis in animal cells

What is cell plate

A new wall-like structure that forms in the middle of a plant cell during cytokinesis, eventually becomes the new cell wall between two cells

Where in the cell cycle are the four major checkpoints?

After G1, After S, After G2, After Metaphase

What are tumors

Out of control cell growth

What are benign tumors

No negative effects, localized

What are malignant tumors

Negative effects, spread