Chapter 5 Biology Test Review

prophase

the nucleolus begins to disintegrate

anaphase

chromatids separate at the beginning of this stage

metaphase

chromosomes move toward center of cell

anaphase

a chromatid from each pair is attracted to each pole of the cell

telophase

the reappearance of the nucleolus can be noticed and a nuclear membrane forms around each set of chromosomes

telophase

nuclear membrane forms from ER

metaphase

separate spindle fibers become attached to the centomeres of each chromosome

prophase

separate chromosomes are not clearly visible but the chromatin has become thicker and shorter

prophase

in the middle of this stage, the nucleolus has completely disappeared

anaphase

in animal cells, the cell membrane begins to pinch together at the cell’s center

telophase

the chromosomes lose their distinct forms and once again reappear as a mass of chromatin

prophase

microtubules form as tiny fibers between the poles

cytokinesis

in animal cells, the cell membrane pinches together completely so that the single cell is separated into two daughter cells

telophase

in plants, the cell plate begins to appear midway through the cell

cytokinesis

in plants, the cell plate is completed to form daughter cells

prophase

in animal cells, the centrioles seperate

telophase

the cell plate forms membranes of golgi bodies or ER

G1

cells grow, carry out normal functions, and replicate their organelles.

Synthesis

DNA is replicated

G2

additional growth occurs

G0

Cells that divide rarely are considered to be in what phase?

external factors

come from outside the cell, either from nearby cells or from another part of the organism's body

internal factors

come from inside the cell and include several types of molecules found in the cytoplasm

kinase

an enzyme that, when activated, transfers a phosphate group from ATP to a specific target molecule

cyclins

a group of proteins that are rapidly made and destroyed at certain points in the cell cycle

apoptosis

programmed cell death; occurs when internal or external signals activate genes that help produce self-destructive enzymes

cancer

a class of diseases characterized by uncontrolled cell division

cell theory

all organisms are made of cells; all existing cells are produced by other living cells; the cell is the most basic unit of life

robert hooke

created the name “cell”

DNA

molecule that stores genetic information in all organisms

chromosome

long, continuous thread of DNA that consists of numerous genes and regulatory information

chromatid

one half of a duplicated chromosome

chromatin

the material that chromosomes are composed of; contains proteins, DNA, RNA

centromere

the region of a chromosome to which the microtubules of the spindle fibers attach during cell division

mitosis

process by which a cell divides its nucleus and contents

centrosomes

small region of cytoplasm that produces protein fibers called microtubules

Centrioles

minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division

sex cells

which cells do not go through the cell cycle

sexual reproduction

involves the joining of two specialized cells called gametes (eggs and sperm cells), one from each of two parents

sexual reproduction

produces offspring that are genetically unique because they have a mixture of genes from both parents

true

true or false: prokaryotes and some eukaryotes reproduce asexually

binary fission

asexual reproduction in which a cell divides into two equal parts

cell differentiation

process by which unspecialized cells develop into their mature form and function

stem cells

cell that can divide for long periods of time while remaining undifferentiated

gene

specific region of DNA that codes for a particular protein