lecture 8- mitosis Flashcards
what is cell division
organisms ability to reproduce
continuity of life through reproduction
roles of cell division
reproduction
growth and development
tissue renewal/repair
what is a chromatin
dna when the cell is not dividing
what is a chromosome
dna during cell division
(chromatin tightly coiled around histones)
what is a genome
all the genetic material in a cell
what does each chromosome contain
huge molecule of dna and proteins
what is the gene locus
the specific place where a gene is located on a specific chromosome
how many chromosomes are there in the human genome
46 (number of chromosomes doesn’t mean how advanced a species is)
what is a karyotype
organized profile of a person’s chromosomes
how is a karyotype arranged
stained
arranged by size (largest to smallest)
photographed
what are the 23 pairs of chromosomes
22 autosomes
1 sex chromosomes
what is the use of karyotypes
to check irregularities in the number or structure of chromosomes
why do you need an x sex chromosome
it has important genes for blood clotting and eyesight
what does having an extra chromosome lead to
potentially down syndrome
what is a haploid cell and examples
cell that has 23 chromosomes
egg and sperm
N
what are diploid cells and examples
23 pairs of chromosomes
all somatic cells
2N
what is a somatic cell
cell that isn’t gametic
what happens when the sperm and egg cell unite
the nuclei fuse together to form a single nucleus
when does the cell cycle happen
between the time a cell is formed and when it divides into two daughter cells
what are the characteristics of mitosis
results in two identical cells
occurs during growth and repair
in somatic cells
what are the stages in the cell cycle
interphase (G1, S, G2)
mitotic phase (mitosis, cytokinesis)
how long does interphase happen compared to the mitotic phase
interphase is most of the cells lifespan (95%)
what are the phases of interphase
growth 1
dna synthesis
growth 2
characteristics of growth 1
period of active growth (increases in size until it reaches mature size for cell type)
synthesis of new organelles
dna is in chromatin form
what happens during dna synthesis
the chromatins are copied