chromosome
made of DNA, which carries genetic information in the form of genes.
genes
is a length of DNA that codes for a protein.
allele
An allele is an alternative form of a gene
How many pairs of chromosomes are in each body cell of a human?
23 pairs
one pair that determines sex:
XX=female
XY=male
who always contribute X chromosome?
mom
who contribute X or Y chromosome?
dad
a haploid nucelus
A haploid nucleus (n) contains one set of chromosomes (e.g., gametes like sperm and egg).
haploid nucleus example
gametes like sperm and egg
diploid
A diploid nucleus (2n) contains two sets of chromosomes
diploid examples
all body cells
mitosis
a type of nuclear division that produces genetically identical cells.
roles of mitosis
Growth
Repair of damaged tissues
Replacement of old cells
Asexual reproduction
meiosis
a nuclear division that produces four genetically different haploid cells
roles of meiosis
-genetic variation
-production of gametes
-supports sexual reproduction
inheritance
the transmission of genetic information from one generation to the next.
genotype
the genetic makeup of an organism
phenotype
the observable traits or characteristics of an organism
homozygous
having two identical alleles of a gene.
heterozygous
having two different alleles of a gene.
