Interim 2 review

Meiosis- forming sex cells Process in which haploid cells are formed from diploid cells In humans: Parent 46 46 Parent Diploid (2N) Diploid (2N) Ovum 23 23 Sperm Haploid (N) Haploid (N) Zygote 46 Diploid (2N) Chromosome number cut in half Fertilization

Mitosis vs Meiosis Characteristic Mitosis Meiosis Cells produced Body cells (somatic cells) Sex cells (gametes) Chromosome number Same as parent cell Diploid 2N Half number of parent cell Haploid N Number of divisions 1 2 Number of cells produced 4

Meiosis Meiosis I Meiosis II

Meiosis homologous Cut in ½ chromatids During meiosis I, the ______________________ chromosomes separate. What does this do to the chromosome number? During meiosis II, the sister ____________________ separate. homologous Cut in ½ chromatids

Meiosis I

Meiosis II Prophase II Metaphase II Anaphase & Telophase II

Meiosis in Males and Females Males- results in 4 sperm cells Females- results in one ovum (egg) and 3 polar bodies MALES FEMALES 1st cell division 2nd cell division 4 Sperm cells 3 polar bodies 1 ovum

If three cells undergo meiosis in males, how many sperm cells will be produced? _____________ If four cells undergo meiosis in females, how many ova (eggs) will be produced? _____________ How many polar bodies would be produced for the same 4 cells? __________________ 12 4 12

16 32 16 16 32 If the 2N number of an organism is 32; how many chromosomes are found in a sperm cell? _______ how many chromosomes are found in a diploid cell? _______ how many chromosomes are found in an ovum? _______ how many chromosomes are found in a haploid cell? _______ how many chromosomes are found in a skin cell?________ 16 32 16 16 32

. Sexual reproduction is important to the survival of the species because it adds genetic _________________________ to the population. variation

Genetic variation Crossing Over- exchange of genetic information by non- sister chromatids during meiosis.

Mistakes in the Meiosis Nondisjunction- failure of chromosomes to separate properly

Genetics Vocabulary ________________- the passing of traits from parents to offspring ________________- the study of heredity _________________- rod-shaped structures in the nucleus that transmits genetic information _________________- units of hereditary information found on the chromosomes heredity genetics chromosomes genes

Genetics Vocabulary __________________- a gene that masks the expression of another gene in a pair ( Symbol- capital letter) __________________- a gene in a pair that is hidden by the dominant gene (Symbol- lower case letter) ___________________- two genes in a pair that are identical. (RR or rr) _____________________- individual with one dominant and one recessive gene in a pair. (Rr) dominant recessive homozygous heterozygous

Genetics Vocabulary ______________________- either member of a pair of genes that determines a single trait. ____________________- the pair of alleles represented by the capital and lower case letters. ______________________- the trait that is actually expressed in an organism allele genotype phenotype

Immunity to poison ivy is a dominant trait while those people who get poison ivy show the recessive trait. Diagram a Punnett Square for a man who is heterozygous and a woman who get poison ivy. I i 1. What is the man’s genotype? ___________ 2. What is the woman’s genotype? ____________ 3. What is the probability of producing a child who gets poison ivy? __________ 4. What is the genotypic ratio?___________ Ii i Ii ii ii Ii ii 50% 1:1

Feather color in birds is an incomplete dominant trait Feather color in birds is an incomplete dominant trait. Genes for blue feathers and genes for white feathers combine to form birds with silver feathers. Diagram a cross for two silver feathered birds. B W 1. What is the parent’s genotype? ___________ 2. What is the phenotypic ratio? ____________ 3. What is the probability of producing bird with blue feathers? __________ 4. What is the probability of producing a bird with silver feathers?___________ BW B W BB BW 1:2:1 25% BW WW 50%

AA, AO, AB, BO A O 1:1:1:1 2:1:1 A B AA AO 50% AB BO Blood type is a codominant trait. A man with blood type AO marries a female with blood type AB. 1. What are the genotypes in the offspring? ___________________ 2. What is the genotypic ratio? ____________ 3. What is the phenotypic ratio? __________ 4. What is the probability of producing a child with blood type A? _______ 5. What is the probability of producing a child with blood type O? ______ AA, AO, AB, BO A O 1:1:1:1 2:1:1 A B AA AO 50% AB BO

XBY Xb Xb Xb Xb XB Y XBXb XBXb 50% XbY XbY 50% Eye color in canaries is a sex-linked trait. Black eyes are dominant and red eyes are recessive. A red-eyed female is crossed with a black-eyed male. What is the male’s genotype? __________ 2. What is the female’s genotype? _________ What is the probability of producing a 3. black-eyed female? _______ 4. black –eyed male? _______ 5. red-eyed female? ________ 6. red-eyed male? __________ XBY Xb Xb Xb Xb XB Y XBXb XBXb 50% XbY XbY 50%

phosphate sugar base Label the three parts of the nucleotide below. ______________ B.______________ C.______________ sugar base

In DNA, how do the bases bond? _____________ bonds with ____________ and Adenine Thymine Cytosine Guanine

What is the name of the process in which DNA makes an exact copy of itself? __________________________ Replication

3 1 2 4 Put the steps of DNA replication below in order. 1. Free floating nucleotides attach to complementary bases on both sides 2. Sugars and phosphates join together on the new strands 3. DNA molecule unzips 4. Two DNA molecules are produced each made of one new strand and one template ________→ ________→ ________→ ________ 3 1 2 4

Comparison of DNA and RNA Strands Sugar Base Pairs Location 2 1 deoxyribose ribose A with T C with G A with U C with G Nucleus to cytoplasm nucleus

Transcription nucleus Translation cytoplasm ribosome Protein Synthesis is divided into two processes. Process 1- _____________________________-mRNA is made by copying the code from a DNA molecule. This process occurs in the __________. Process 2-_____________________________- a protein is assembled from amino acids. This process occurs in the _______________ at a _____________________. Transcription nucleus Translation cytoplasm ribosome

Genetic information usually follows in one specific direction (Central dogma of biology). Which of the following BEST represents this flow? A.) DNA-->Protein-->RNA B.) Protein-->RNA-->DNA C.) RNA-->Protein-->DNA D.) DNA-->RNA-->Protein

Three bases on the mRNA molecule that code for one amino acid is a(n) A.) anti-codon. B.) codon. C.) tRNA. D.) protein.

C U G A A U G U C Transcribe the section of DNA below. G A C T T A C A G C U G A A U G U C

5 4 1 3 2 tRNA Amino acid mRNA Protein ribosome Label parts 1 through 5 in the diagram. 1. _______________ 4. _______________ 2. _______________ 5. _______________ 3. _______________ 5 4 1 3 2 tRNA Amino acid mRNA Protein ribosome

5 4 1 3 2 Translation What is the name of the process in the picture? _____________________ 5 4 1 3 2 Translation

Mutation Insertion Deletion Substitution A mistake in the genetic code is called a ____________________. Name the type of mutation in the DNA sequences below. Use these choices Substitution Insertion Deletion Original strand – CTGACT New strand CTAGACT ___________________ New strand CTGCT ___________________ New strand CTGAGT ___________________ Mutation Insertion Deletion Substitution

Gel Electrophoresis DNA fingerprinting ___________ ____________________ is a method used to separate and analyze DNA fragments. __________ ____________________ is the analysis of DNA fragments to identify an individual. DNA fingerprinting cs s1 s2 s3 s4 s5 CS= crime scene DNA s1= suspect 1 s2= suspect 2 s3= suspect 3 s4= suspect 4 s5= suspect 5