What is genetics?

1. What is genetics? 01. Genetics is the study of inherited traits.

2. Where is genetic information stored? 02. Genetic information is stored in the nucleus.

3. What is DNA? 03. DNA is a biological molecule that has atoms arranged in a code for inherited traits.

4. How many chromosomes are in each somatic (body) cell? 04. There are 46 chromosomes in each somatic cell.

5. How many chromosomes are there in each germ (sex) cell? 05. There are 23 chromosomes in each germ cell.

6. What is a karyotype? 06. A karyotype is arranged pictures of chromosomes.

7. If a mother and father have a baby boy, how did the boy inherit his gender? 07. A baby boy inherits its gender by getting a Y chromosome from the Dad and an X chromosome from the Mom.

8. 01. What is an allele? 01. An allele is a variation of a gene.

9. 02. Define the word homozygous. 02. Homozygous is having two or more alleles that are all the same.

10. 03. Define the word heterozygous. 03. Heterozygous is having two or more alleles that are different from each other.

11. 04. Define the word genotype. 04. A genotype is a list of alleles that an organism has.

12. 05. Define the word phenotype. 05. A phenotype is what an organism looks like.

13. 06. Define the word dominant, as it pertains to genetic traits. 06. Dominant is a trait that is always expressed when present. Only one allele is needed for the trait to be expressed.

14. 07. Define the word recessive, as it pertains to genetic traits. 07. Recessive is a trait that is hidden by the dominant trait when the dominant trait is present. The recessive trait is only expressed when homozygous.

15. 01. Explain a co-dominant pattern of heredity. 01. A co-dominant pattern is when both alleles for a gene are expressed at the same time.

16. 02. Explain a sex-linked pattern of heredity. 02. A sex-linked pattern is when the alleles for a trait are on the sex chromosomes and are inherited with the sex chromosomes.

17. 03. Explain a pattern of heredity that results from multiple alleles. 03. When more than two alleles produce numerous variations in a gene, this pattern of variations is the result of multiple alleles.

18. 04. Explain a pattern of heredity that results from polygenic inheritance. 04. Polygenic inheritance is when more than two genes are needed in order for a trait to be expressed.

19. 05. Define the word pedigree. 05. A pedigree is a graphic representation of an individual’s inherited traits.

20. 06. Define the word carrier. 06. A carrier is an individual who has a recessive trait that can be passed to offspring.

21. 07. Name a genetic disorder and explain how it is inherited. 07. Cystic Fibrosis is inherited by receiving a recessive allele from each parent (so are Parkinson’s and PKU; Huntington’s is an inherited dominant trait).

22. 01. What is a diploid number of chromosomes and where are they found? 01. A somatic cell with two of each kind of chromosome, or 2n number of chromosomes, is called a diploid cell.

23. 02. What is a haploid number of chromosomes and where are they found? 02. A germ cell with one of each kind of chromosome, or n number of chromosomes, is called a haploid cell.

24. 03. Homologous chromosomes are similar, paired chromosomes that have the genes in the same order, but may have different alleles for the same genes. 03. What are homologous chromosomes?

25. 04. What is a zygote? 04. The cell that results from the sperm fertilizing an egg; it has a diploid number of chromosomes.

26. 05. What is the result of meiosis? 05. The result of meiosis is genetic recombination and a haploid number of chromosomes in specialized cells called gametes.

27. 06. What are the four basic stages of cell division? 06. The four basic phases of cell division are prophase, metaphase, anaphase, and telophase.

28. 07. What is “crossing over” and during what phase of meiosis does crossing over occur? 07. When homologous chromosomes come together in tetrads, sometimes they exchange genetic information. This happens during prophase I in meiosis.