Presentation on theme: "Patterns of Heredity 4.1 Living things inherit traits in patterns. 4.2"— Presentation transcript:
1 Patterns of Heredity 4.1 Living things inherit traits in patterns. 4.2 the BIG ideaIn sexual reproduction, genes are passed from parents to offspring in predictable patterns.4.1Living things inherit traits in patterns.4.2Patterns of heredity can be predicted.4.3Meiosis is a special form of cell division.
2 Living things inherit traits in patterns. sexual reproductionsexual reproductionA type of reproduction in which male and female reproductive cells combine to form offspring with genetic material from both cells.genehereditygeneThe basic unit of heredity that consists of a segment of DNA on a chromosome.hereditydominantThe passing of genes from parents to offspring; the genes are expressed in the traits of the offspring.recessive
3 Living things inherit traits in patterns. dominantsexual reproductiongeneA term that describes the allele that determines the phenotype of an individual organism when two different copies are present in the genotype.heredityallelephenotyperecessivegenotypeA term that describes an allele that is not expressed when combined with a dominant form of the gene.dominantrecessive
4 Patterns of heredity can be predicted. 4.2Patterns of heredity can be predicted.Punnett squares show possible outcomes of heredity.Punnett squareRatios and percentages can be used with Punnett squares to express the probability of particular outcomes.ratioprobabilitypercentageBbB = black furb = brown furBBBbbb
5 Meiosis is a special form of cell division. 4.3Meiosis is a special form of cell division.• At the beginning of meiosis I, the parent cell has two copies of each chromosome pair.gamete• During meiosis I, the homologs of the chromosome pair separate; there are two cells, each with two copies of one homolog from each pair.eggsperm• During meiosis II, the two copies of each homolog separate; each daughter cell has one homolog.fertilizationmeiosisMeiosis I1nMeiosis II
6 gameteA sperm or egg cell, containing half the usual number of chromosomes of an organism (one chromosome from each pair), which is found only in the reproductive organs of a plant or animal.eggA female reproductive cell (gamete) that forms in the reproductive organs of a female and has just a single copy of the genetic material of the parent.spermA male reproductive cell (gamete) that forms in the reproductive organs of a male and has just a single copy of the genetic material of the parent.
7 fertilization meiosis Part of the process of sexual reproduction in which a male reproductive cell and a female reproductive cell combine to make a new cell that can develop into a new organism.meiosisA part of sexual reproduction in which cells divide to form sperm cells in a male and egg cells in a female. Meiosis occurs only in reproductive cells.
8 4.1 Living things inherit traits in patterns. I. Living things inherit traits in patterns.sexual reproductionA. Parents and offspring are similar.geneB. Genes are on chromosome pairs.heredityC. Gregor Mendel made some important discoveries about heredity.allelephenotype1. One Examplegenotypedominant2. Mendel’s ConclusionsrecessiveD. Alleles interact to produce traits.1. Phenotype and GenotypeCHAPTERRESOURCES2. Dominant and Recessive AllelesKEY CONCEPTSUMMARY
9 Patterns of heredity can be predicted. 4.2Patterns of heredity can be predicted.II. Patterns of heredity can be predicted.Punnett squareA. Punnett squares show possible outcomes for inheritance.ratioprobabilityB. Ratios and percentages can express the probability of outcomes.percentageCHAPTERRESOURCESKEY CONCEPTSUMMARY
10 Meiosis is a special form of cell division. 4.3Meiosis is a special form of cell division.III. Meiosis is a special form of cell division.gameteA. Meiosis is necessary for sexual reproduction.eggB. Cells divide twice during meiosis.sperm1. Meiosis Ifertilization2. Meiosis IImeiosisC. Meiosis and mitosis differ in some important ways.CHAPTERRESOURCESKEY CONCEPTSUMMARY