Year 10 Science – Genetics

Term 2 Weeks 10-11

What you have to know:

Lessons 1,2,3,4   DNA

  • DNA -Double helix structure (c  hemical structure of DNA)
  • Chromosomes, Genes and DNA notes: yr10GeneticsLessons1_2  ,                  Science Focus Chapter 4_4  yr10ScFocus4pg114_118TheMoleculeOfLIfe4_4   ,      worksheet: What are Chromosomes yr10wsWhat are Chromosomes
  • DNA, chromosome – DNA is found in the nucleus of the cell. DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.DNA consists of two long chains of nucleotides twisted into a double helix and joined by  bases. A nucleotide is made up of sugar phosphate and bases. The four bases are: adenine and thymine or cytosine and guanine.  DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule.
  • DNA  – Double Helix Structure Models
  •   
  • DNA – double helix structure “twisted ladder”
    • DNA model (using lollies)  see photos below:
    • DNA model lollies
  • DNA (double helix)
  • Pairing up the bases in DNA   – activity
  • Differrent organisms have different number of chromosome.
  • DNA from bbc bitesize website (page 1 and for extension work refer to pages 2,3,4)
  •   Differrent organisms have different number of chromosome.  (video 5 mins – simple explanation)
  • DNA structure  (video by geneticists – Dr Suzuki – bbc program  for extension work)
  • Term 2 Week 1-2   DNA replication
  • Why DNA replication is important?
    • Why is DNA replication important for cells?
    When a cell divides, both daughter cells need to have identical DNA to function properly. In order to get two identical sets of DNA the parent cell makes an extra copy before splitting. This process is called DNA replication. All cells must replicate their DNA prior to cell division. This assures that each new cell produced receives all of the genetic material necessary to survive (growth and repair) and reproduce.
  • Notes: yr10GeneticsLesson5_6DNAReplication
  • How DNA replicate?  (video)
  • DNA extraction – fruits (strawberry) worksheet from Murdoch University.

Term 2 Week 2 and 3:  Two types of Cell divison (Mitosis and Meiosis)

Revision:

Background knowledge:

  • The cell theory states that:
  1. All living organisms are made from one or more cells.
  2. Cells comes from pre-existing cells.
  3. All life functions takes place within the cells.
  4. The cell is the smallest unit of living organisms life.cell
  • plant cells and animal cells
  • plant cells and animal cells – drag and label activity
  • Chromosomes: –  Chromosomes consist of DNA (double helix shape). Chromosomes contain genetic instructions of the living organisms and pass the characteristics of the organisms to the offspring (next generation). Chromosomes are found in the nucleus of the nucleus of plant or animal cell.  Chromosomes are tightly packed so they fit into the nucleus of the cell.
  • Why is DNA replication important for cells?
When a cell divides, both daughter cells need to have identical DNA to function properly. In order to get two identical sets of DNA the parent cell makes an extra copy before splitting. This process is called DNA replication. All cells must replicate their DNA prior to cell division. This assures that each new cell produced receives all of the genetic material necessary to survive (growth and repair) and reproduce.
  • DNA -structure discoverd by Watson and Crick

lecture by James Watson Co-discoverer of DNA structure

  • Cell Division

Cell division is the process that cells go through in order to divide and it is important for growth, repair (replacement) and reproduction. There are two types of cell division: meiosis and mitosis. Meiosis is the cell division to make new sex cells in the sexual reproduction. It takes place in the reproduction organs (in the ovary for the female and testis for the male). The other type, the cell division associated with growth and cell replacement or repair, is called mitosis.

  • Cell Division – Meiosis    (to make sex cells i.e. sperms (male) or ova or eggs (female)
  • Reproduction – cell division (bbc)
  • Fertilisation  – animation
  • Cells division- Meiosis

4.2 Cell Division – Mitosis

4.3. How is meiosis different from mitosis?

Mitosis Meiosis
Makes body cells Makes sex cells
Produces 2 cells Produces 4 cells
Reduces the number of chromosomes to half (haploid number) Number of chromosomes remains the same (diploid number)
One cell divison Two cell divisions

Cell Division – Mitosis – to make body cellsv

5. Mutation

Mutation is a change in the DNA sequence of a gene. It can be caused by radiation (UV, X-rays and harmful radiations from radioactive materials), food additives such a food colouring and chemicals such as agent orange (a defoliant used in the Vietnam war).

Mutation- mermaid syndrome

Mutation – Chernobyl disaster

Mutation – museum

Mutation:  Down Syndrome

More information on genetic diseases.

More information on genetics on the bbc website-  revise, try the activity and do a test.

Background knowledge:

  • The cell theory states that:
  1. All living organisms are made from one or more cells.
  2. Cells comes from pre-existing cells.
  3. All life functions takes place within the cells.
  4. The cell is the smallest unit of living organisms life.cell
  • plant cells and animal cells
  • plant cells and animal cells – drag and label activity
  • Chromosomes: –  Chromosomes consist of DNA (double helix shape). Chromosomes contain genetic instructions of the living organisms and pass the characteristics of the organisms to the offspring (next generation). Chromosomes are found in the nucleus of the nucleus of plant or animal cell.  Chromosomes are tightly packed so they fit into the nucleus of the cell.
  • Structure of DNA (Deoxyribonucleus acid)
  • DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.DNA consists of two long chains of nucleotides twisted into a double helix and joined by  bases. A nucleotide is made up of sugar phosphate and bases. The four bases are: adenine and thymine or cytosine and guanine.  DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule.Why is DNA replication important for cells?
When a cell divides, both daughter cells need to have identical DNA to function properly. In order to get two identical sets of DNA the parent cell makes an extra copy before splitting. This process is called DNA replication. All cells must replicate their DNA prior to cell division. This assures that each new cell produced receives all of the genetic material necessary to survive (growth and repair) and reproduce.
  • DNA -structure discoverd by Watson and Crick

6 Vocabulary

6.1   Bases:   adenine and thymine or cytosine and guanine.    Adenine is represented by “A”, Thymine by “T”, Cytosine by “C”, guanine by “G”.   “A”  links with “ T”  while “ C ” links with “G”.

6.2  Cancer: is an uncontrollable cell division where it fail to produce differentiated cells.

6.3 Cell division:  cell divides by pinching one cell into two.

6.4 Chromosomes: It contains genetic instructions of the living organisms and pass the characteristics of the organisms to the offspring.

6.5 DNA  : DeoxyriboNucleic Acid (double helix structure -like a twisted ladder) DNA packed together to form chromosome so it can fit into the nucleus.  A DNA Nucleotide:  It is made made up of  sugar, phosphate and base

6.6 Mitosis : a type of cell division to produce body cells with diploid number (same number of chromosome). This type of cell division produces cells for growth and repair.

6.7 Meiosis: a type cell division to produce sex cells with haploid number (number of chromosome is halved). This  type of cell divison produces sex cells.

6.8 Mutation: is  a change in the DNA sequence of a gene to some new, heritable form.

6.9 Replication: a process where a cell divides, both daughter cells need to have identical DNA to function properly. In order to get two identical sets of DNA the parent cell makes an extra copy before splitting in cell division.

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