300 likes | 359 Vues
Explore the location and function of germ cells in the human body, the difference between somatic and germ cells, and the process of meiosis in cell division. Discover how chromosomes play a role in genetic inheritance.
E N D
6.1 Chromosomes and Meiosis 2.1 Atoms, Ions, and Molecules Set up Cornell Notes on pg. 63 • Topic: 6.1 Chromosomes and Meiosis • Essential Question: • Where are germ cells located in the human body? • Where are germ cells located in the human body? Key Concept: Gametes have half the number of chromosomes that body cells have
XX XY Pg. 62 Germ Cells Somatic Cells Points to Ponder
With a partner from your table: • Please use pgs. 168-171 in your text book • USE PENCIL • Complete the tree map of chromosomes (2 branches) • Complete the table contrasting: Somatic/Germ Cells
KEY CONCEPT Gametes have half the number of chromosomes that body cells have.
Mom Dad • Human body cells have 23 pairs of chromosomes and 46 total • Each pair of chromosomes is called Homologous pairs and have copies of the same genes • In each pair, one chromosome comes from each parent. *Homo= same
You have two types of chromosomes: Autosomes and Sex Chromosomes
Chromosome pairs 1-22 are called autosomes • Contain genes not directly related to your gender
Pair #23=Sex chromosomes: X and Y • determine gender • Control the development of sexual characteristics XX= female XY= male XX P. 62: Draw a picture to help you remember XX/XY XY
You have two types of specialized cells: Somatic cells andGerm cells Will become… Draw a picture on the middle of pg. 62 to help you remember somatic vs. germ cells
Somatic cells- are body cells, and make up most of your body tissues and organs. • Liver cells • Lung cells • Heart cells etc… Red blood cells skin cells bone cells intestinal cells
Somatic (body) cells are Diploid (2n) • They have two copies of every chromosome (23 from mom, 23 from dad) • for a TOTAL of 46 chromosomes • Undergo mitosis *di= 2 n (sperm) n (egg) 2n
Germ cells- are the cells in your reproductive organs • located in the ovaries and testes • Develop into gametes through meiosis
Gametes are sex cells: egg and sperm • Both have DNA that can be passed to offspring. Egg Sperm
Gametes are Haploid (n) cells have one copy of every chromosome. • Have 22 autosomes + 1 sex chromosome = 23 chromosomes each • Each gamete is UNIQUE 23 23
Chromosomes Autosomes Sex Chromosomes Sets 1-22 Set 23 Not directly related to gender X Y Determines gender Controls sexual characteristics
Undergo meiosis • Cells in reproductive organs (ovaries/testies) • Become gametes (sperm/eggs) • Haploid • 23 chromosomes • Each are Unique • Undergo mitosis • body cells • Diploid • 46 chromosomes • Identical to parent cell • You have two types of specialized cells: Somatic cells Germ cells
Points to Ponder • Where are germ cells located in the human body (2 places) • Do you think that Y chromosomes contain genes that are critical for an organism’s survival? Explain.
Points to Ponder • Where are germ cells located in the human body (2 places) • In the reproductive organs: The ovaries in women and the testes in men. 2. Do you think that Y chromosomes contain genes that are critical for an organism’s survival? Explain. • No, a Y chromosome is not necessary for survival. Females do not have a Y chromosome, and they are able to survive.
6.1 Mitosis vs. Meiosis 2.1 Atoms, Ions, and Molecules Set up Cornell Notes on pg. 65 • Topic: 6.1 Mitosis vs. Meiosis • Essential Questions: • Does mitosis or meiosis occur more frequently in your body? Explain. • Draw a double-bubble map comparing and contrasting mitosis and meiosis (pg. 64) • Does mitosis or meiosis occur more frequently in your body? Explain. • Draw a double-bubble map comparing and contrasting mitosis and meiosis
Pg. 64 EQ#2: Mitosis Meiosis “Genetic Data Chromosome Interpretation”
Pg. 65 Mitosis Meiosis
Mitosis= makes more diploid cells. • Produces genetically identical cells • Results in diploid cells (2 sets of chromosomes) • 46 chromosomes in each cell • Takes place throughout an organism’s lifetime • Involved in asexual reproduction • Somatic (body) Cells
*Draw on pg. 65 in mitosis column DNA replicates 2 identical daughter cells
Meiosis= makes haploid cells (23) from diploid cells • Produces genetically unique cells • Results in haploid cells (1 set of chromosomes) • 23 chromosomes in each gamete • Takes place only at certain times in an organism’s life cycle • Involved in sexual reproduction • Germ cells (sex cells)
(diploid- 46) Germ cell *Draw on pg. 65 in meiosis column 4 haploid (23) unique daughter cells
Homework: Due by Tuesday 10/28!!!! Work on vocab on pg. 68-69 of INB You need each vocab word- as well as a mini pic and description • 6.1 • Sexual reproduction • Fertilization • Meiosis • 6.4 • Gene • Allele • Homozygous • Heterozygous • Genome • Genotype • Phenotype • Dominant • Recessive • 6.3 • Traits • Genetics • Purebred • 6.2 • Sperm • Egg
Classwork EQ: Make a double-bubble Map comparing and contrasting mitosis and meiosis on the top of Pg. 64. • Please read the Genetic Data information • Interpret the second bar graph and answer the 3 questions on the bottom of pg. 64 • Title it “Genetic Data Chromosome Interpretation” Data Analysis: Please open your book to page 172
Diploid # of Chromosomes in Various Organisms Y- axis Dependent variable 210 10 20 40 49 55 40 X- axis Independent variable
King crab; fruit fly • No. A porpoise is much bigger than a king crab, and has far less chromosomes. A potato is only 3 chromosomes off from human, and far smaller. • Yes. Chromosomes need to be able to fit in the nucleus.