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1 Lecture 2 Cell, Genes and phenotype
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2 Cell, Gene expression and phenotype Cellular Organization DNA and RNA Structure and Function Gene expression How is sex determined Chromosomes Genotype & Phenotype Dominant & Recessive traits
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4 Plasma Membrane Model
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5 Nucleus and Nuclear Membrane
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6 Ribosomes Ribosomes are found singly or in groups (polyribosomes) in the cytoplasm. – Function in protein synthesis.
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7 The Endomembrane System- also function in protein synthesis Endoplasmic Reticulum. – System of membranous channels and saccules. Rough ER is studded with ribosomes and synthesizes proteins. Smooth ER synthesizes phospholipids, as well as various other functions.
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8 The Endomembrane System- process final products and monitor incoming vesicles The Golgi Apparatus. – Consists of a stack of three to twenty curved saccules, along with vesicles. Receives protein and or lipid vesicles that bud from the ER. Lysosomes. – Membranous sacs produced by the Golgi apparatus that contain hydrolytic digestive enzymes.
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9 Endomembrane System
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10 Mitochondria- The “powerhouse” Mitochondria are double-membrane organelles involved in cellular respiration. – Site of ATP production.
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11 Cellular Respiration
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12 The Cytoskeleton The cytoskeleton is formed of several types of filamentous structures that give the cell its shape and organelles the ability to move about the cell. – Microtubules. – Actin Filaments.
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13 Centrioles Centrioles are short cylinders composed of microtubules that are involved in spindle formation during cell division
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14 Cilia and Flagella Cilia and flagella (cilium, flagellum) are projections that move in an undulating or whipping fashion. – Cilia tend to be shorter while flagella tend to be longer.
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15 Cellular Metabolism Cellular metabolism includes all the chemical reactions that occur in a cell. – Often organized into metabolic pathways. Most regulated by feedback inhibition.
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16 Enzymatic Action
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17 The Nucleus The nucleus stores genetic information that determines body cell characteristics and metabolic functioning. Nucleus is separated from the cytoplasm by a nuclear envelope. Contains nuclear pores to permit passage of proteins and ribosomal subunits.
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18 DNA and RNA Structure and Function DNA is the genetic material found principally in chromosomes. – In between cell divisions, chromosomes exist in long fine threads of chromatin. When a cell is about to divide, chromosomes coil and condense.
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19 DNA Location and Structure
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20 DNA Structure and Replication DNA is a sequential series of joined nucleotides. – Sugar (deoxyribose), phosphate, and base. Adenine (A). Thymine (T). Cytosine (C). Guanine (G). nucleotides
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21 DNA Structure and Replication DNA is a double helix with a sugar- phosphate backbone and bases projecting between the backbones. – Exhibits complementary base pairing. A-T. G-C.
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22 DNA Replication/ cell division Mitosis and Meiosis (replacing cells or making babies)
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23 Can DNA replication cause mutations?
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24 Structure and Function of RNA- protein synthesis (the way we look) RNA is made up of nucleotides containing the sugar ribose and the base uracil in place of thymine. – Single stranded. RNA is a helper to DNA allowing protein synthesis.
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25 Gene Expression Structure and Function of Proteins. – Proteins are composed of amino acids. Proteins differ because the number and order of their amino acids differ.
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27 How is the Sex of a Child Determined? Fetus development Genes and environment Sexual characteristics
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28 Do chromosomes help determine sex? Sex chromosomes Human sex ratio – Sex ration at birth 1:1.05 – Young males die early – Females live longer
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29 Chromosomes Male Karyotype
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32 Gametogenesis
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33 Genotype and Phenotype Genotype refers to an individual’s genes. – Alleles are alternate forms of a gene. Dominant alleles are assigned uppercase letters, while recessive alleles are assigned lowercase letters. Homozygous Dominant = EE. Homozygous Recessive = ee. Heterozygous = Ee. Phenotype refers to an individual’s physical appearance.
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34 Genetic Inheritance
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35 Dominant/Recessive Traits Forming the Genes. – Reduction of chromosome number occurs when pairs of chromosomes separate as meiosis occurs.
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