Download Cellular Reproduction Life Structure and Function

Cellular Reproduction
Life Structure and Function
Atoms & Molecules make up the
components of DNA
Chromosomes are structures in the nucleus that contain hereditary material.
Chromosomes consist of large amounts (one molecule) of DNA wrapped around
histone proteins, coiled up and condensed in the nucleus
The centromere is the part of the chromosome that links sister
chromatids together
They serve as a checking point in mitosis to ensure the proper
separation of the chromosomes
Homologous chromosomes pair up based on similar size, shape, and genetic
information (traits)
One chromosome comes from the maternal parent (mom) & the other chromosome is from
the paternal parent (dad)
DNA is copied for
two main reasons:
1) Cell division
(growth, repair, &
replacement of cells)
2) Making proteins
(proteins regulate cell
processes &
make cell structures)
The cell cycle consists of 3 main
stages
• Interphase (longest stage)
• Mitosis
• cytokinesis
Cell Cycle
The cycle begins with
one diploid cell and ends
with two daughter cells
(A diploid cell has paired
chromosomes one from
each parent)
Interphase
During this stage of the cell cycle, chromatin, nuclear envelope and nucleolus are
clearly visible
(In animal cells the centrioles are also visible)
Mitosis (mitotic phase)
There are four phases in mitosis….
Prophase
Metaphase
Anaphase
Telophase
Prophase
(1st stage of mitosis)
The chromosomes condense and become visible in the nucleus of the cell and the
spindles begin to form in the cytoplasm
Metaphase (2nd stage of mitosis)
Spindle fibers connect to the centrioles that are at opposite poles from each other. The duplicated chromosomes are lined up in the middle
along the metaphase plate