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
Replicate body cells
skin, muscle, bone
Replicate sex cells
ovum (egg), sperm
# of daughter cells
2 diploid cells
4 haploid cells
# of divisions
Chromosome #

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

   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 punnett_square.jpg
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,

 Phenotype - Physical appearance
Genotype - Genetic makeup
1. Hair color
 brown, black, or red hair DOMINANT
 LL or Ll

 blond hair                         recessive
2. Hair type
 naturally curly             DOMINANT    
 TT or Tt

 naturally straight            recessive
3. Tongue curling
 can curl tongue            DOMINANT
 CC or Cc

 cannot curl tongue         recessive
4. Mid-digital hair
 hair present, middle digit of finger
 MM or Mm

 hair absent, middle digit of finger
5. Pigmented iris
 eyes not blue
 EE or Ee

 blue eyes
6. Widow's peak
 peak in center of hairline
 WW or Ww

 no peak in center of hairline
7. Bent finger
 little finger curves toward others
 BB or Bb

 little finger straight


Post a Comment