1. Genetics Crash Course
7th grade science

2. Traits
Physical Characteristics

3. Genes
Bits of information in DNA that control traits

4. Heredity
The passing of traits from parents to offspring

5. Chromosomes “Containers” of genes. Humans have 46 chromosomes
Half come from mother, half come from father.

6. Checkpoint What is heredity?
How many total chromosomes do humans have?
Why are your chromosomes arranged in pairs?

7. Two Types of Reproduction
Asexual and Sexual

8. Asexual Reproduction Reproduction involving one parent
Offspring is genetically identical to parent
Budding
Cell division
Splitting

9. Sexual Reproduction Reproduction involving two parents
Genetically unique offspring
Half chromosomes from mom, half from dad

10. Fertilization
A sperm and egg unite to form a zygote

11. Checkpoint
Which type of reproduction results in genetically identical offspring?
Which type of reproduction involves two parents?
Which type of reproduction? A red flower is bred with a white flower in hopes of producing a pink flower.

12. Mitosis The way eukaryotic cells divide Asexual reproduction
Results in exact copy of parent cell (same number of chromosomes)

13. Meiosis The way gametes (sex cells) divide
Offspring has half the number of chromosomes.
Why is this important?

14. Checkpoint Mitosis or Meiosis? New human cells have 23 chromosomes
Makes exact copies
New human cells have 46 chromosomes
Makes gametes

15. Patterns of Inheritance
Gregor Mendel – studied the heredity of pea plants

16. Allele
Different variations of genes

17. Dominant
Hides the recessive allele
Always expressed if present

18. Recessive
Only shows up if there is no dominant

19. Genotype
The genetic makeup of an organism

20. Phenotype
The physical expression of the genes

21. Homozygous
Both alleles are the same TT tt

22. Heterozygous
Both alleles are different Tt

23. Punnett Squares
T T Tt Tt
t t Tt Tt

24. Checkpoint Indicate if each is heterozygous or homozygous TT Pp dd
If orange tail (T) is dominant to blue tail (t), what would be the phenotypes for each genotype? TT Tt tt

25. Checkpoint
If orange tail is dominant to blue, what are the chances of two heterozygous parents producing an orange tail offspring?

26. Genetic Diseases Some diseases are spread through genes Not contagious
Cystic fibrosis
Sickle cell anemia

27. Pedigrees
Chart used to track genetic history through families

28. Checkpoint How many males? How many females?
How many have the condition?
How many carriers?

29. Nature vs. Nurture Not all traits are controlled only by genes
It is a combination of genes and environment.