Genetics: Meiosis, Traits, and Inheritance

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

Meiosis Meiosis I Meiosis II

Meiosis • 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 • 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?________ 32 16 16 32

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

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 dominant • __________________- 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) 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 i Ii ii ii 50% Ii ii 1:1

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%

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? ______ • Blood type is a codominant trait. A man with blood type AO marries a female with blood type AB. AA, AO, AB, BO A O 1:1:1:1 2:1:1 A B AA AO 50% AB BO 0

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% 0 XbY XbY 0 50%

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

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

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

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 2 1 deoxyribose ribose A with T C with G A with U C with G Nucleus to cytoplasm nucleus

Transcription • 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 _____________________. 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.

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

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

Mutation • 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 ___________________ Insertion Deletion Substitution

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

Genetics: Meiosis, Traits, and Inheritance

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