Biology Chapter 6

Genome

The complete set of genes or genetic material present in a cell or organism.

Genetics

the study of heredity

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

Ribosome

Cytoplasmic organelles at which proteins are synthesized.

Amino Acid

Building blocks of protein

Protein

A three dimensional polymer made of monomers of amino acids.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Centromere

Area where the chromatids of a chromosome are attached

Chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

DNA replication

The process in which DNA makes a duplicate copy of itself.

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.

homologous pair

a pair of chromosomes, one from each parent, that have relatively similar structures and gene values

Cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

Mutation

A change in a gene or chromosome.

Proto-oncogenes

the corresponding normal cellular genes that are responsible for normal cell growth and division

Oncogenes

cancer causing genes

tumor suppressor genes

A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer.

Karyotype

A picture of all the chromosomes in a cell arranged in pairs

Mitosis

part of eukaryotic cell division during which the cell nucleus divides

cell cycle

series of events that cells go through as they grow and divide

Cytokinesis

Division of the cytoplasm during cell division

Interphase

the resting phase between successive mitotic divisions of a cell, or between the first and second divisions of meiosis.

mitotic phase

stage of the cell cycle when a cell is actively dividing

Microtubules

Spiral strands of protein molecules that form a tubelike structure

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

spindle apparatus

structure made of spindle fibers, centrioles, and aster fibers that is involved in moving and organizing chromosomes before the cell divides

Kinetochores

The structures on sister chromatids where microtubules attach

metaphase plate

Plane midway between the two poles of the cell where chromosomes line up during metaphase.

mitotic spindle

a structure made of microtubules that controls chromosome movement during mitosis

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Metaphase

Chromosomes line up in the middle of the cell

Telophase

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin

cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Cell plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

Binary Fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Clone

An organism that is genetically identical to the organism from which it was produced

sex chromosomes

Chromosomes that determine the sex of an individual

reasons cell divide.

To grow and develop, you must form new cells. Imagine how often your cells must divide during a growth spurt. ...
Cell division is also necessary to repair damaged cells. ...
Your cells can also simply wear out.

Differentiate between prokaryotic and eukaryotic cell division.

Prokaryotic cells have a single circular chromosome, no nucleus, and few other cell structures. Eukaryotic cells, in contrast, have multiple chromosomes contained within a nucleus, and many other organelles.

Outline binary fission.

Binary fission, asexual reproduction by a separation of the body into two new bodies. In the process of binary fission, an organism duplicates its genetic material, or deoxyribonucleic acid (DNA), and then divides into two parts (cytokinesis), with each n

Purpose of mitosis and how it is accomplished.

Mitosis is a process where a single cell divides into two identical daughter cells (cell division). During mitosis one cell. Divides once to form two identical cells. The major purpose of mitosis is for growth and to replace worn out cells.

Describe the structure of a eukaryotic chromosome.

one very long linear DNA molecule associated with many proteins

Compare and contrast sister chromatid and homologous pairs.

Sister chromatids are 2 copies of a single chromosome and so are genetically identical
Homologous chromosomes are 2 physically different chromosomes that have the same genes but are not genetically identical

Describe the role of microtubules in mitosis.

Microtubules attach to the to a structure on the sister chromatids called the kinetochore. Throwing the chromosomes into an agitated motion moving them towards the center of the cell. Then during anaphase they will help with the migration of chromosomes t

Compare and contrast cytokinesis in animal and plant cells.

Cytokinesis occurs in mitosis and meiosis for both plant and animal cells. The ultimate objective is to divide the parent cell into daughter cells. In plants , this occurs when a cell wall forms in between the daughter cells. In animals , this occurs when

Describe how the cell controls division.

Tight regulation of this process ensures that a dividing cell's DNA is copied properly, any errors in the DNA are repaired, and each daughter cell receives a full set of chromosomes.

Identify the checkpoints and describe the role each checkpoint plays in control of the cell cycle.

The cell cycle is controlled at three checkpoints. The integrity of the DNA is assessed at the G1 checkpoint. Proper chromosome duplication is assessed at the G2 checkpoint. Attachment of each kinetochore to a spindle fiber is assessed at the M checkpoint