3 4.1 VocabSexual reproduction – a cell containing genetic information from the mother and a cell containing genetic information from the father combine into a completely new cell, which becomes the offspring.
4 4.1 Vocab Cont.Gene – the basic unit of heredity that consists of a segment of DNA on a chromosomeHeredity – the passing of genes from parents to offspringAlleles – various forms of a gene. Can be dominant or recessive.
5 Genotype – genes an organism has. Phenotype – the actual characteristics that can be observedDominant allele – can be observed in the phenotype even if only one copy is present in the genotypeRecessive allele – only observed in the phenotype if two copies are present in the genotype
6 Living things inherit traits in patterns. allelesa geneOffspring inherit alleles, which are forms of genes, from their parents. Alleles come on chromosome pairs and can be dominant orrecessive.The alleles you have are your genotype; the observable characteristics that come from your genotype are your phenotype.SIMULATIONTry a virtual version of Mendel’s experiment.CLASSZONE.COMCHAPTERRESOURCESSECTIONOUTLINE
7 Bell Work 10/1/10 Please use complete sentences What is the difference between a genotype and a phenotype?Explain why a person with an allele for a particular trait may not have a phenotype that shows the trait.
8 4.2 NotesPunnett square – illustrates how the parents’ alleles might combine in offspring (ratio, percentage)BbB = black furb = brown furBBBbbb
9 Homozygous – both traits are the same (both dominant or both recessive) Heterozygous – traits are different (one dominant one recessive)
10 Bell Work 10/4/10Draw a punnett square for the following cross then write down the phenoype and genotype ratios and percentages.Y = yellow flower y = white flowerA heterozygous yellow flower is crossed with a homozygous white flower.
11 Read page 116 and answer #1-3 at the bottom (not the example) Bell Work 10/5/10Read page 116 and answer #1-3 at the bottom (not the example)
12 Vocab 4.3Gametes – cells that contain half the usual number of chromosomes. (one chromosome from each pair) 1n cell or haploid cellsEgg – a gamete that forms in the reproductive organs of a female. 1n cell or haploid cellsSperm – a gamete that forms in the reproductive organs of a male. 1n cell or haploid cellsFertilization – the process that takes place when a sperm and egg to form one new cell. 2n cell
13 Bell Work 10/6/10Write each sentence, then decide if these statements are true. If not true, correct them.Mitosis produces four genetically identical daughter cells.In sexual reproduction, offspring inherit traits from both parents.Genetic traits are inherited in random patterns.
14 Meiosis Takes place in the reproductive tissues of an organism A single cell goes through two cell divisions (meiosis I and meiosis II)
15 Meiosis IStep 1 - Prophase IChromosomes condenseDuplicated chromosomes pair up with their partnersThe nuclear membrane disappears
16 Meiosis IStep 2 - Metaphase IChromosome pairs line up in the middle of the cell
17 Meiosis IStep 3 - Anaphase IChromosome pairs separate and are pulled to opposite ends of the cell
18 Meiosis IStep 4 - Telophase I and CytokinesisNuclear membranes formCell divides into two daughter cells