1. Genetics and Heredity Review

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8 brown, two: 4white, three: 2 brown, three: 2 white two
6BbYY:2BbYY:2bbYY:2Bbyy:2bbyy:2bbYy BY By bY by
BbYY
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3. Chromosomes Each of our body cells contain 23 pairs of chromosomes.
And, so, logically it follows that each of our body cells contains 46 chromosomes. (MATH!? In Science? I know… it’s simply madness…)
So, how many chromosomes are in any sperm or egg cell??? 23!!!

4. Karyotypes are KOOL A Karyotype is the number
and appearance of chromosomes in
the nucleus of a eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism. Karyotypes describe the number of chromosomes, and what they look like under a microscope.

5. Sexual vs. Asexual Reproduction
Uniform Offspring
Asexual
Diverse Offspring
Sexual
Single Parent
More than one parent
Like a clone
Sperm and egg unite
Sperm and egg not involved

6. Genes that Determine Sex/Gender
An X-Shaped structure is called a CHROMOSOME
Genes within your body code for a specific TRAIT.
The 23rd pair of chromosomes in your body determine your sex.

7. What about heredity?
The scientific study of heredity is called genetics.
So, when traits pass from parents to children, we call that heredity.
The "Father of genetics" is Gregor Mendel
He used pea plants to perform his research
We know that TRAITS are controlled by genes located in the DNA.

8. Alleles •ALLELES are just different forms of a gene
•Because of this, every person inherits one ALLELE from the mother and one ALLELE for that same trait from the father.
•We call strong alleles the DOMINANT allele.
•Weaker alleles are called the RECESSIVE allele.

9. The letters inside a Punnett square represent GENOTYPES.
SpongeBob SquarePants recently met SpongeSusie Roundpants at a dance. SpongeBob is homozygous dominant for two big front teeth, but SpongeSusie has small front teeth. Create a Punnett square to show the possibilities that would result if SpongeBob and SpongeSusie had children. HINT: Large teeth are dominant.
Possible Genotypes for their Children: Tt
Possible Phenotypes for their Children: Large Front Teeth
Their children have a 4 out of 4 or 100% chance to have large front teeth.
The children have a 0 out of 4 or 0% chance to have SMALL front teeth.
!*Remember*!--> A Hybrid is an organism with a dominant AND a recessive allele
The letters inside a Punnett square represent GENOTYPES.

10. Genes that Determine Sex
If the 23rd pair of chromosomes is an XX, the gender is FEMALE
If the 23rd pair of chromosomes is an XY, the gender is MALE
The number of chromosomal pairs that a species has does NOT correlate with specific levels of intelligence or size with the organism.

11. Genotype vs. Phenotype rr = Genotype Red Hair = Phenotype
Rolling Tongue = Phenotype
Tt = Genotype

12. ALLELLES Recessive Alleles
•Recessive alleles are HIDDEN, but may be passed down from parents to their offspring.
•A recessive allele can ONLY show up if another RECESSIVE ALLELE is also present. We need TWO (2) recessive alleles to see them show up.