that does not happen during mitosis?

Transcription

1 Review! What is a somatic cell?! What is a sex cell?! What is a haploid cell?! What is a diploid cell?! Why is cell division important?! What are the different types of cell division?! What are these useful for?! What are the products? 1

2 ! What are gametes?! How are gametes made?! How many chromosomes do gametes have?! Why is this important?! How is meiosis different from mitosis?! What are the key differences?! What are the different stages of meiosis?! What important step occurs during meiosis that does not happen during mitosis?! Why is this step important?! Why is meiosis important? 2

3 Complete the missing parts or circle the appropriate answer: 23 Mum and dad both have pairs of chromosomes diploid 2(n)/ haploid (n) (circle one). parents They inherited one from each of their. To make the next generation, DNA is mixed up for genetic diversity during Meiosis/Mitosis (circle one). Alleles homologous genes randomly places. swap Each mixed-up chromosome goes into its own diploid 2(n)/haploid (n) sex cell (circle one). 4 genetically different cells form. The next generation gets one mixed up chromosome from each. DNA parent 1. Correct number of chromosomes in each cell (in the circles provided) 2. Missing words (on the lines provided) 3

4 ma egg Grand Meternal (mother s side) pa sperm ma egg Paternal (father s side) Grand Grand pa sperm Grand mom My dad 46 My 46 Meiosis I genes shuffle Meiosis II four genetically different cells form gametes - egg gametes - sperm My brother 46 ME 46 My sister 46 Offspring

5 How can siblings look alike but not exactly the same if they come from the same parents?

6 Mitosis vs Meiosis Where it occurs Mitosis All over the body Meiosis Sex organs (testes and ovaries) No. of divisions 1 2 Cells produced by the process Ploidy: Daughter cells are Somatic cells (normal body cells) Diploid 2(n) (full set of chromosomes) Gametes (sex cells sperm/egg) Haploid (n) (half-set of chromosomes) No. of chromosomes No. of daughter cells Purpose Growth, development, replacement of damaged cells Sexual reproduction

7 Mutations are any changes that take place in DNA: Mutations can be spontaneous or caused by mutagens such as chemicals, high temperatures, UV light, radiation Mutations change the genetic code, and be replicated when forming new body cells. Mutations in sex cells, can be passed on to offspring. Mutations can be neutral, beneficial, or harmful for example: blue eyes a mutation that occurred 6-10,000 years ago, can be traced back to one ancestor.

8 THE DOG BIT THE CAT

9 DNA and Mutations - Substitution THE DOG BIT THE CAT Substitution - Replace just one letter: THE DOG BIT THE CAR

10 DNA and Mutations - Deletion THE DOG BIT THE CAT Deletion: Delete just one letter (T): THE DOG BIT HEC AT

11 DNA and Mutations-Insertions THE DOG BIT THE CAT Insertion - Add just one letter (E): THE DOE GBI TTH ECA T Cells have proof reading proteins that constantly check the DNA and fix errors, so most are corrected.

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13 Mutations - review! Cells continually carry out many complex processes and functions.! Mutations are mistakes that result in changes of DNA these can be neutral, good and also bad!! Mistakes and mutations happen all the time and are largely responsible for the diversity of life. 13

14 Genetics vocabulary You should have these key words, their definitions and descriptions in your glossary:! Genetics! Heredity! DNA! Base pair! Gene! Allele! Dominant genes! Recessive genes! Chromosome! Trait! Physical trait! Behavioural trait! Discrete variation! Continuous variation! Phenotype! Genotype! Mitosis! Meiosis Few more on the next page! 14

15 Genetics vocabulary! Somatic cell! Sex cell! Gametes! Diploid cell! Haploid cell! Mutations 15

16 Revision Videos (to help you study) Introduction to genetics:! v=b_pq8qytul0&index=8&list=plisbhwljxpn2bmljfishkcihpbpcov24o What are genes?! Introduction to DNA:! v=m4zhvrlxkgw&index=11&list=plisbhwljxpn2bmljfishkcihpbpcov24o Where do your genes come from?! What are phenotypes:! Few more on the next page! 16

17 More videos on genetics Cell division and the cell cycle/ Mitosis:! Meiosis:! Mutations:!