CELL DIVISION INTRODUCTION
________________
- the study of how ________________ or ________________
are passed on from one ________________ to another.
________________
- to be passed on from one generation to ________________.
i.e. Inherited from your ________________
________________
-(________________________________) - a complex double
helix molecule made up of ________________, sugars and
________________ pairs. This molecule carries the genetic
information that determines ___________________________
________________
- a sequence on a piece of ________________ that controls a
particular ________________. A ________________ is at least
3 ________________ long ( may be much longer)
________________
- a ________________ unit in the cell ( usually seen during cell
________________) that contains a strand of ________________
and protein wound together. It has ________________ of genes in
it.
CHROMOSOME TRIVIA:
- Humans have ________________ of chromosomes:
_____ somatic pairs
_____ of sex chromosomes
( ___ = female, ___ = male)
- There are ________________ possible chromosome combinations ( ___ )
- Humans have about ________________ genes on these chromosomes
- About ________________ nucleotide pairs in our DNA
________________
- a single ________________ from a chromosome _____________
________________
- where 2 ________________________________ are connected
________________
- structure inside the cells used to help cells and _______________
________________.
________________
- sex cell (________ or _______) made by ________________.
REASONS FOR CELL DIVISION:
1. ________________ - as an organism grows it must produce _______________or
if a cell gets too large it must ________________.
2. ________________________________ - when cells or tissues are damaged or die
they must be replaced by ________________ cells or at least cells that do the
identical ________________.
3. ________________ - when cells or organisms want to reproduce they must divide
or produce cells that are the ________________.
4. ________________________________ - in sexually reproducing organisms the
production of ________________ or sex cells occurs. ________________ or
________________.
________________
- a cellular division where 2 new cells are made that are
________________________________. Each new cell has
it’s own ________________ with a full set of
________________.
________________
- a cellular division where new cells are produced that have
________________ of chromosomes. This produces
________________ (sex cells) and occurs only in the
________________ organs of sexually reproducing
organisms.
CELL DIVISION INTRODUCTION
GENETICS
- the study of how TRAITS or CHARACTERISTICS
are passed on from one GENERATION to another.
HEREDITARY
- to be passed on from one generation to THE NEXT.
i.e. Inherited from your PARENTS
DNA
-( DEOXYRIBONUCLEIC ACID ) - a complex double
helix molecule made up of PHOSPHATES, sugars and
NUCLEOTIDE pairs. This molecule carries the genetic
information that determines ALL CHARACTERISTICS
GENE
- a sequence on a piece of DNA that controls a
particular TRAIT. A GENE is at least
3 NUCLEOTIDES long ( may be much longer)
CHROMOSOME
- a ROD-LIKE unit in the cell ( usually seen during cell
DIVISION) that contains a strand of DNA
and protein wound together. It has THOUSANDS of genes in
it.
CHROMOSOME TRIVIA:
- Humans have 23 PAIRS of chromosomes:
22 somatic pairs
_1 PAIR of sex chromosomes
( XX = female, XY = male)
- There are 8 388 608 possible chromosome combinations ( 223 )
- Humans have about 100 000 genes on these chromosomes
- About 8 BILLION nucleotide pairs in our DNA
CHROMATID
- a single STRAND from a chromosome PAIR
CENTROMERE
- where 2 SISTER CHROMATIDS are connected
Chromatid
Chromosome
Centromere
SPINDLE APPARATUS
- structure inside the cells used to help cells and
CHROMOSOMES DIVIDE
Spindle Apparatus
Centriole
GAMETE
- sex cell ( EGG or SPERM ) made by MEIOSIS
REASONS FOR CELL DIVISION:
1. GROWTH - as an organism grows it must produce MORE CELLS or if a cell
gets too large it must DIVIDE.
2. REPAIR AND REPLACEMENT - when cells or tissues are damaged or die they
must be replaced by IDENTICAL cells or at least cells that do the identical JOB.
3. REPRODUCTION - when cells or organisms want to reproduce they must divide
or produce cells that are the SAME.
4. PRODUCTION OF GAMETES - in sexually reproducing organisms the
production of GAMETES or sex cells occurs. EGGS or SPERM.
MITOSIS
- a cellular division where 2 new cells are made that are
GENETICALLY IDENTICAL. Each new cell has it’s own
NUCLEUS with a full set of CHROMOSOMES
MEIOSIS
- a cellular division where new cells are produced that have
½ A SET of chromosomes. This produces GAMETES (sex
cells) and occurs only in the REPRODUCTIVE organs of
sexually reproducing organisms.