I. How are gametes different from somatic cells?
1. Somatic Cells
A. Body Cells
i. Eyes, Liver, Spleen
A. Sex Cells
i. Sperm, Eggs
a. Sperm- Male Sex Cells
b. Eggs- Female Sex Cells
II. What do the terms haploid and diploid mean?
A. A cell only has one copy of each chromosome
i. Somatic Cells
A. A cell has two copies of each chromosome
III. What are homologous chromosomes?
1. Two chromosomes--one inherited from the mother, one from the father--that have the same general appearance.
A. Have copies of the same genes
i. Copies may differ
IV. Compare and contrast meiosis and mitosis
A. Form of nuclear division that divides diploid cells into haploid cells
i. Essential for sexual reproduction
A. Used to repair and replace cells in all organisms
i. Used for reproduction in asexually reproducing eukaryotes V. How does meiosis keep our chromosome number constant over several generations? 1. Meiosis regulates chromosomes by dividing until there is a set number of chromosomes.
a. Mitosis begins after that
VI. Differentiate between homologous chromosomes and sister chromatids.
1. Homologous Chromosomes
A. Are two chromosomes--one inherited from the mother, one from the father--that have the same general appearance.
2. Sister Chromatids
A. Condensed Duplicated Chromosome
VII. During which phase of meiosis does a cell go from being diploid to haploid? What exactly is happening here?
1. Meiosis II
A. Meiosis II is when sister chromatids divide
VIII. Know generally the steps of Meiosis
1. Proteins May be Amino acids Today/I Promised Mom A Turkey
i. Nuclear membrane breaks down
i. Spindle fibers align homologous chromosomes along equator
i. The paired homologous chromosomes separate from each other and move toward opposite sides of the cell.
i. Spindle fibers disassemble and the cell undergoes cytokinesis. IX. Be able to describe Mendel’s experiments, including the reason why he chose pea plants 1. Mendel crossed different types of pea plants to observe genetics A. He crossed wrinkled and round pea plants
B. He crossed purple and white flowering pea plants
2. Pea plants are easy to grow
A. Many advantages
i. easy to grow
ii. can keep many generations
iii. easy to observe
X. How does genotype affect phenotype?
A. Genotypes are the possibilities that can become phenotype
A. Phenotype is the trait that is expressed
XI. Understand that different alleles for a certain gene are found on homologous chromosomes- these alleles are not identical, but they are similar because they code for the same trait XII. Be able to do monohybrid and dihybrid crosses- be able to figure out the probability that one phenotype will occur over another XIII. Be able to explain Mendel’s Law of Independent Assortment
1. The law states that allele pairs separate independently during the formation of gametes.
A. The ratio is 9:3:3:1
Independent Assortment: The
traits of pod color and seed color
are transmitted to the offspring
independently of one another.
XIV. What are advantages to sexual reproduction/meiosis?
1. Offspring will be genetically unique
2. Species can evolve more efficiently
XV.What is crossing over? When does it occur? Why is it beneficial? 1. Crossing over is the exchange of genes between homologous chromosomes, resulting in a mixture of parental characteristics in offspring. 2. Crossing over happens during prophase 1 of meiosis
3. Crossing over is beneficial because the genetics for the offspring differs from the parent. XVI. What does it mean for a person to be a carrier of a disease?
1. Being a carrier means that you are heterozygous and the recessive trait does not show but is in your genes.
A. There is a possibility that you will...
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