1. 32. Cell Cycle Events Interphase Cell Division
Longest phase of the cell cycle.
DNA is in chromatin form
G1- Growth (organelles duplicate)
S- replication (duplication) or DNA
G2- Cell Growth
Prophase- chromosomes
Metaphase- Chromosomes align along the metaphase plate (middle)
Anaphase- sister chromatids separate
Telophase- Cleavage furrow begins and nuclear envelopes reform.
Cytokinesis- division of the cytoplasm (two new cells)

2. 33.
If a skin cell had 52 chromosomes, how many chromosomes would be found in an egg cell? 26

3. 34.) Compare and contrast mitosis and meiosisds ds
Only once through division cycle
Goes through division cycle twice
Go through interphase (cell growth) majority of time
At anaphase 1, Homologous chromosomes separate
At anaphase, sister chromatids separate
Go through PMAT (second division of meiosis is similar to mitosis)
At cytokinesis, two identical cells separate
At cytokinesis 1, two haploid daughter cells are formed
Chromosome # is identical as the original cell
Chromsosome # is half of the original cell and a UNIQUE combination
TWO IDENTICAL DIPLOID CELLS
Makes BODY (somatic) cells
FOUR UNIQUE HAPLOID CELLS
Makes GAMETES (egg and sperm)

4. 35. Non-disjunction
Nondisjunction is the failure for duplicated chromosomes to separate
Generally during Meiosis II
Down syndrome is also known as TRISOMY 21.
Three copies of the 21st chromosome

5. 36. Describe the shape and composition of a DNA molecule
Shape: Double Helix
Composition:
Phosphate group
Deoxyribose sugar
1 of 4 nitrogen bases

6. 37. What is the function of DNA?
The function of DNA is to store heredity information that will be passed down to generations. It also contains the code for generating mRNA; this will eventually lead to tRNA, rRNA, and eventually proteins.

7. 38) Base Pairing A-T (adenine to thymine) C-G (cytosine to guanine)
Bonded by hydrogen bonds
2 bonds between A and T
3 bonds between C and G

8. 39) DNA vs. RNA DNA RNA A,T,C,G Deoxyribose sugar Double helix
More complex
A,U,C,G
Ribose sugar
Single Strand
Less complex

9. 40) Codons Set of three nucleotides on the mRNA strand
Instructions for amino acids which then leads to protein production
Codes for amino acids
3 letters make up a codon

10. 41) mRNA sequence mRNA: UUC GUU GGA ACC DNA: AAG CAA CCT TGG
Amino acid: Phe-Val-Gly-Thr

11. 42 a. Point Mutations Substitution
Point where one nitrogen base is substituted for another
Sickle Cell Anemia: substitute A for T

12. 42 b. Frame Shift Mutations
Deletions and Insertions
When a nitrogen base is deleted or added
Frame shift mutations- because it moves the
codon up or down
Changes the sequence of amino acids after the mutation

13. 43) Transcription vs. Translation
DNA to RNA
Occurs in nucleus
RNA to protein
Occurs in cytoplasm

14. 44.) Define the following terms:
Genotype: The genetic makeup of an organism
Phenotype: The physical traits of an organism
Homozygous: Having two identical alleles for a given gene
Heterozygous: Having two different alleles for a given gene
Dominant: In a heterozygote, the allele that determines the phenotype with respect to a particular gene (the larger letter)
Recessive: In a heterozygous individual, the allele that has no noticeable effect on the phenotype (the smaller letter)

15. 45. How are the following words related? DNA, gene, RNA, protein, trait
Gene (stretch of DNA) that is transcribed into RNA, that is translated into PROTEIN, that is expressed as a TRAIT

16. 46. Punnett Square
tool used to determine the probability of traits being passed on to offspring based on parents genotypes
Parents genotypes represent egg and sperm
Offspring's genotypes represent body cells

17. 47. a)Monohybrid Heterozygote Parents (Tt x Tt) b) Blonde hair is dominant to brown. Two parents are mated one with blonde hair and one with brown, and some of their children end up with blonde and some with brown. a) b)
Parent 1- Bb
Parent 2- bb

18. 48.
Children born with a recessive genetic disorder can have parents that do not express the disorder, because the parents are heterozygous.
The parents have the gene for the disorder, but it is masked by the dominant gene.
This is how some traits can “skip” a generation.

19. 49. Gene Pool
Gene pool is the available genes in a breeding population.

20. 50.
Species can achieve genetic variation over many generations by breeding outside of the immediate family.
No inbreeding
This allows new genes to be introduced

21. 51.
A species can loose genetic diversity overtime by not “adding” to the gene pool.
Inbreeding
No gene shuffling