Test Review

How do cell replicate?
Mitosis is how body cell duplicate, skin, muscle, neurons. 

Meiosis is how sex cells duplicate, ova (egg), sperm.

Cell division type	Mitosis	Meiosis
Function	Replicate body cells skin, muscle, bone	Replicate sex cells ovum (egg), sperm
Reproduction	Asexual	Sexual
Genetically	Identical	different
# of daughter cells	2 diploid cells	4 haploid cells
# of divisions	1	2
Chromosome #	46	23

Stages of Mitosis and Meiosis
 Deoxyribonucleic acid (DNA) is a molecule encoding the genetic instructions used in the development and functioning of all known living organisms. Heredity is how we pass these coded traits on to our children. Genetic information is encoded as a sequence of nucleotides ( adenine, thymine, and cytosine, guanine,) recorded using the letters 
A,T & C, G for the base pairs with backbones (side of double helix) made of alternating sugars (deoxyribose) and phosphate groups Most 

DNA molecules are double-stranded helices.








Heredity is how we pass these coded traits on to our children.


Homozygous are alleles of the same type, such as RR, rr.
Heterozygous  are combinations with both a dominant and recessive allele, such as Bb.

A dominant (D) allele will be expressed or seen (in phenotype) if it is homozygous (RR) or if it
        is heterozygous (Rr)
    A recessive (r)  allele is expressed (seen in phenotype) when it is paired (2) with another recessive 
       allele of the same type (such as LL, ll). It is masked when combined with a dominant allele (such
       as in Ll).
Phenotype - Physical appearance
Genotype - Genetic makeup

 Homozygous Dominant
    PP = Dominant color

Heterozygous
   Pp = Dominant color


Homozygous recessive
    pp = recessive color

 

The History of Heredity

Modern genetics begins with the work of Gregor Mendel, an Austrian monk whose breeding experiments with garden peas led him to formulate the basic laws of heredity.

In one experiment, Mendel cross-pollinated smooth yellow pea plants with wrinkly green peas.

Mendel postulated that there are dominant and recessive traits in heredity.

In his experiment Mendel marked with capital letters dominant traits and with small letters recessive traits.
R = dominant round shape
r = recessive wrinkly shape



                                                                   Heterozygous (Aa)
                                                        1  Parents Genes Aa

2 Parent Genes AA
Homozygous (AA)     Result: All offspring's phenotype will have allergies. 2 offspring will be homozygous for the dominant trait Allergies, the other 2 heterozygous for allergies.


Homozygous alleles are purebred, HH, hh.
Heterozygous alles are hybrid, ex. Hh, Rr,

Trait	Phenotype - Physical appearance	Genotype - Genetic makeup
1. Hair color	brown, black, or red hair DOMINANT	LL or Ll
	blond hair                         recessive	ll
2. Hair type	naturally curly             DOMINANT	TT or Tt
	naturally straight            recessive	tt
3. Tongue curling	can curl tongue            DOMINANT	CC or Cc
	cannot curl tongue         recessive	cc
4. Mid-digital hair	hair present, middle digit of finger	MM or Mm
	hair absent, middle digit of finger	mm
5. Pigmented iris	eyes not blue	EE or Ee
	blue eyes	ee
6. Widow's peak	peak in center of hairline	WW or Ww
	no peak in center of hairline	ww
7. Bent finger	little finger curves toward others	BB or Bb
	little finger straight	bb