The Cell Cycle Flashcards
what is cell division
-ability of organisms to reproduce
-continuity of lifeis based on the reproduction of cells (passing on genetic info)
roles of cell division
reproduction
growth and development
tissue renewal and repair
what is a chromatin
dna when the cell is not dividing (present in long thin threads)
what is a chromosome
dna during cell division (chromatin tightly coils around histones)
what characteristics are controlled by genes
hair
skin
flower color
where are genes located
on the chromosomes
what are genomes
all the genetic material in a cell
what does each chromosome contain
huge molecule of dna and proteins
contains a larger number of genes
what is the gene locus
the specific place on a chromosome where a gene is located
where does each gene occur
occurs on a specific chromosome at a specific site on the chromosome
how many are in a human
46 (23 from mom and 23 from dad)
true or false: number of chromosomes doesn’t mean how advanced the species is
true
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 (non sex)
1 sex chromosomes
what are karyotypes used for
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
it is sex defining
what does karyotype arrangement do
helps scientists quickly identify chromosomal alterations that may result in gentic disorders
what does having an extra chromosome lead to
Down syndrome (trisomy 21)
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 are non reproductive chromosomes called
autosomal or autosomes
what do autosomes do
-they don’t code for sex characteristics (m/f)
-found in somatic cells and gametes (but in diff quantities)
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 = zygote
what is a zygote
a fertilized egg
when does the cell cycle happen
between the time a cell is formed and when it divides into two daughter cells
what is the cell cycle
describes the series of events that occur in nearly every cell
what is the process that follows after a zygote is formed
-initial cell divides into 2 then those 2 into 4 then those for into 8…
-basically the og genetic info is copied (cloning)
what are the characteristics of mitosis
-results in 2 identical body cells
-occurs during growth and repair
in somatic cell division
what is the purpose of meiosis
gives rise to gametes that hav half the number of chromosomes as the og cell