Chapter 4
Interphase: the stage in which makes copies of its genetic material in preparation for mitosis (
longest part of the cell cycle
- G1: rapid growth and cell activity
- S: replication of dna
- G2: preparation for cell division
Mitosis: the stage in which a cell’s nucleus and genetic material divides.
- Prophase: cells’ chromatin condenses into chromosomes. There are 2 copies of DNA
and they are attached together by the centromere and called sister chromatids. The
nuclear membrane breaks down. Centrosomes move apart to opposite poles of the cell.
- Metaphase: The sister chromatids line up in the middle of the cell and the spindle fibers
attaches to the centromeres
- Anaphase: spindle fibers pull apart the sister chromatids and split the centromere and
gather at each end of the pole.
- Telophase: The spindle fibers break down, the nuclear membrane reforms and the new
sets of chromosomes and a new nucleus is formed.
Cytokinesis: involves the division of the cell cytoplasm and creation of 2 new cells.
- Plant cells: which the cytoplasm is partitioned by the construction of a new cell wall, the
cell plate, inside the cell
- Animal cells: the cell membrane gets divided into two by the formation of a cleavage
furrow that keeps deepening through a contractile ring in the center of the parent cell.
Sex cells = gamete cells (only one pair)
Autosome cells = refers to all chromosomes except sex cells ( 22 pair )
Karyotype
- A photograph of pairs of homologous chromosomes in a cell
,Sexual reproduction
Interphase
Meiosis 1
- Prophase 1: each pair of homologous chromosomes line up side by side and perform
synapsis. Synapsis(crossing over) is the process of exchanging genetic information
between homologous chromosomes. (provides genetic diversity) continues as normal
prophase
- Metaphase 1: same thing
- Anaphase 1: same thing
- Telophase 1: before telophase 1 they are diploid 2n = 46 and after they become n = 23
- Cytokinesis: same thing
Now there 2 new daughter cells and they are haploids ( n )
Meiosis 2
- Prophase 2: same thing
- Metaphase 2: same thing
- Anaphase 2: same thing
- Telophase 2: same thing
- Cytokinesis: same thing
Result in 4 haploid cells
Spermatogenesis = process of sperm production = produces 4 sperm cells
Oogenesis = the process of egg production = 1 visible egg and 3 polar bodies
Errors during Meiosis
Errors caused by changes in chromosome structure
Deletion: a piece of a chromosome is deleted
Duplication: a section of a chromosome appears to have 2 or more times in a row
Inversion: a section of a chromosome is inverted
Translocation: a segment of chromosome becomes attached to a different chromosome.
Insertion: part of a chromosome is inserted into a new place
,Errors caused by changes in chromosome number
Nondisjunction: the process in which the sister chromatids do not separate as they should
during meiosis. ( can occur in anaphase 1 or 2 )
Genetic disorders associated with chromosome number
Down syndrome: have an extra chromosome or an extra piece of chromosome 21
Mosonomy: the condition in which one chromosome is lost due to nondisjunction (XO =
missing chromosome )
Trisomy: the condition of having a gain of an extra chromosome due to nondisjunction. (XXX,
XXY, XYY = extra chromosome)
Karyotype: used to diagnose chromosomal abnormalities such as those caused by
nondisjunction.
Fertilization: produces a diploid zygote from haploid cells
Meiosis: produces haploid cells from diploid cells.
Mitosis produces diploid cells from haploid cells
Meiosis takes place in the testes and ovaries
Reproductive strategies and technologies
Artificial insemination: the process of inserting semen into a female’s reproductive tract.
Cloning: produces identical copies of genes, cells or organisms.
Gene cloning: involves manipulating the DNA to produce multiple copies of a gene or another
segment of DNA in foreign cells.
Therapeutic cloning: involves producing genetically identical cells that are used to treat
various diseases.
Reproductive cloning: involves production of cell clones, but with the aim of producing a
genetically identical organism.
, These two types of cloning use the process of somatic cell nuclear transfer (scnt) to generate
the cloned cells.
Ethical issues
- Inequality
- Payment
- risks
Transgenic organisms are organisms with foreign DNA inserted
Transgenic plants can be used for disease resistance, nutrient value and medical value
Transgenic animals can be used for possible organ donors for humans
Ethical issues
- Health risks
- Animals genes in plants may affect ones religion
- Illnesses are treated with heavy hormones and antibiotics and can piut human health at
risk
- The extent in which CRISPR use should be permitted
CRISPR: gene editing; allows specific genes to be added or removed
Chapter 5
Patterns of Inheritance
Who was Gregor Mendel?
- He was a monk in Vienna (1822 - 1884 )
- Noticed patterns of inheritance among pea plants in the garden of the monastery for
traits such as flower color, pea color, and pea pod shape.
- He conducted crosses among the plants and kept track of what he observed.
3 Mendelian Laws
Law of Segregation: traits are determined by pairs of alleles that segregate during meiosis so
that each gamete receives one allele.
Punnett Squares - monohybrid
Dihybrid - two traits are being monitored
Interphase: the stage in which makes copies of its genetic material in preparation for mitosis (
longest part of the cell cycle
- G1: rapid growth and cell activity
- S: replication of dna
- G2: preparation for cell division
Mitosis: the stage in which a cell’s nucleus and genetic material divides.
- Prophase: cells’ chromatin condenses into chromosomes. There are 2 copies of DNA
and they are attached together by the centromere and called sister chromatids. The
nuclear membrane breaks down. Centrosomes move apart to opposite poles of the cell.
- Metaphase: The sister chromatids line up in the middle of the cell and the spindle fibers
attaches to the centromeres
- Anaphase: spindle fibers pull apart the sister chromatids and split the centromere and
gather at each end of the pole.
- Telophase: The spindle fibers break down, the nuclear membrane reforms and the new
sets of chromosomes and a new nucleus is formed.
Cytokinesis: involves the division of the cell cytoplasm and creation of 2 new cells.
- Plant cells: which the cytoplasm is partitioned by the construction of a new cell wall, the
cell plate, inside the cell
- Animal cells: the cell membrane gets divided into two by the formation of a cleavage
furrow that keeps deepening through a contractile ring in the center of the parent cell.
Sex cells = gamete cells (only one pair)
Autosome cells = refers to all chromosomes except sex cells ( 22 pair )
Karyotype
- A photograph of pairs of homologous chromosomes in a cell
,Sexual reproduction
Interphase
Meiosis 1
- Prophase 1: each pair of homologous chromosomes line up side by side and perform
synapsis. Synapsis(crossing over) is the process of exchanging genetic information
between homologous chromosomes. (provides genetic diversity) continues as normal
prophase
- Metaphase 1: same thing
- Anaphase 1: same thing
- Telophase 1: before telophase 1 they are diploid 2n = 46 and after they become n = 23
- Cytokinesis: same thing
Now there 2 new daughter cells and they are haploids ( n )
Meiosis 2
- Prophase 2: same thing
- Metaphase 2: same thing
- Anaphase 2: same thing
- Telophase 2: same thing
- Cytokinesis: same thing
Result in 4 haploid cells
Spermatogenesis = process of sperm production = produces 4 sperm cells
Oogenesis = the process of egg production = 1 visible egg and 3 polar bodies
Errors during Meiosis
Errors caused by changes in chromosome structure
Deletion: a piece of a chromosome is deleted
Duplication: a section of a chromosome appears to have 2 or more times in a row
Inversion: a section of a chromosome is inverted
Translocation: a segment of chromosome becomes attached to a different chromosome.
Insertion: part of a chromosome is inserted into a new place
,Errors caused by changes in chromosome number
Nondisjunction: the process in which the sister chromatids do not separate as they should
during meiosis. ( can occur in anaphase 1 or 2 )
Genetic disorders associated with chromosome number
Down syndrome: have an extra chromosome or an extra piece of chromosome 21
Mosonomy: the condition in which one chromosome is lost due to nondisjunction (XO =
missing chromosome )
Trisomy: the condition of having a gain of an extra chromosome due to nondisjunction. (XXX,
XXY, XYY = extra chromosome)
Karyotype: used to diagnose chromosomal abnormalities such as those caused by
nondisjunction.
Fertilization: produces a diploid zygote from haploid cells
Meiosis: produces haploid cells from diploid cells.
Mitosis produces diploid cells from haploid cells
Meiosis takes place in the testes and ovaries
Reproductive strategies and technologies
Artificial insemination: the process of inserting semen into a female’s reproductive tract.
Cloning: produces identical copies of genes, cells or organisms.
Gene cloning: involves manipulating the DNA to produce multiple copies of a gene or another
segment of DNA in foreign cells.
Therapeutic cloning: involves producing genetically identical cells that are used to treat
various diseases.
Reproductive cloning: involves production of cell clones, but with the aim of producing a
genetically identical organism.
, These two types of cloning use the process of somatic cell nuclear transfer (scnt) to generate
the cloned cells.
Ethical issues
- Inequality
- Payment
- risks
Transgenic organisms are organisms with foreign DNA inserted
Transgenic plants can be used for disease resistance, nutrient value and medical value
Transgenic animals can be used for possible organ donors for humans
Ethical issues
- Health risks
- Animals genes in plants may affect ones religion
- Illnesses are treated with heavy hormones and antibiotics and can piut human health at
risk
- The extent in which CRISPR use should be permitted
CRISPR: gene editing; allows specific genes to be added or removed
Chapter 5
Patterns of Inheritance
Who was Gregor Mendel?
- He was a monk in Vienna (1822 - 1884 )
- Noticed patterns of inheritance among pea plants in the garden of the monastery for
traits such as flower color, pea color, and pea pod shape.
- He conducted crosses among the plants and kept track of what he observed.
3 Mendelian Laws
Law of Segregation: traits are determined by pairs of alleles that segregate during meiosis so
that each gamete receives one allele.
Punnett Squares - monohybrid
Dihybrid - two traits are being monitored
