CHANGING ENVIRONMENTS And variation Changing environments variation Some

CHANGING ENVIRONMENTS And variation

Changing environments & variation Some environments can change over a long or short period of time.

Changing environments & variation Some environments can change over a long or short period of time. Some organisms have phenotypic variations that allow them to survive these changes.

Changing environments & variation Some environments can change over a long or short period of time. Some organisms have phenotypic variations that allow them to survive these changes. They will breed and pass on to their offspring the genotypes that produce these successful variations.

Droughts Read the information given and highlight points you might use in an exam

Flooding Read the information on flooding and highlight the points you might use in an exam.

Mutations & Variation Mutations create new alleles.

Mutations & Variation Mutations create new alleles. New alleles are the source of variation

Mutations & Variation Mutations create new alleles. New alleles are the source of variation If the variation or new adaptation enhances the individual’s survival, it will spread throughout the population.

Mutations & Variation Mutations create new alleles. New alleles are the source of variation If the variation or new adaptation enhances the individual’s survival, it will spread throughout the population. **Refer to previous information on mutations**

Mutations that occur in body cells These only affect new body cells formed from the mutated cell.

Mutations that occur in body cells These only affect new body cells formed from the mutated cell. The type of cell division involved is mitosis.

Mutations that occur in body cells These only affect new body cells formed from the mutated cell. The type of cell division involved is mitosis. The mutation is not passed onto the affected individual’s offspring.

Mutations that occur in body cells These only affect new body cells formed from the mutated cell. The type of cell division involved is mitosis. The mutation is not passed onto the affected individual’s offspring. EG – a skin cell gets hit by UV from the sun. A mutation occurs and the new cell starts to divide rapidly = skin cancer. This skin cancer is not passed onto this person’s offspring however.

Mutations that occur in the gametes Mutations that form in the egg or sperm will be passed onto the offspring if that egg or sperm is fertilised.

Mutations that occur in the gametes Mutations that form in the egg or sperm will be passed onto the offspring if that egg or sperm is fertilised. EG – There is a mutation in the gene for producing melanin (what makes skin colour) during meiosis. This mutated egg is fertilised and as the zygote divides, all those cells have a mutation for melanin. When the individual is born they will have darker skin than their parents.

Mutations that occur in gametes Most mutations are harmful to an organism – it’s estimated that every person has 4 mutations in their cells and 2 of those could be harmful if expressed in the phenotype.

Mutations that occur in gametes Most mutations are harmful to an organism – it’s estimated that every person has 4 mutations in their cells and 2 of those could be harmful if expressed in the phenotype. Occasionally a mutation results in a trait that can help the organism survive in changed environmental conditions.

Mutations that occur in gametes Most mutations are harmful to an organism – it’s estimated that every person has 4 mutations in their cells and 2 of those could be harmful if expressed in the phenotype. Occasionally a mutation results in a trait that can help the organism survive in changed environmental conditions. The new trait will be passed onto those offspring that survive while others without the new trait die.

Mutations that occur in gametes Most mutations are harmful to an organism – it’s estimated that every person has 4 mutations in their cells and 2 of those could be harmful if expressed in the phenotype. Occasionally a mutation results in a trait that can help the organism survive in changed environmental conditions. The new trait will be passed onto those offspring that survive while others without the new trait die. This new trait then becomes an adaptation.

Read Antibiotic-resistant Bacteria info and highlight key points. Pesticide resistance and highlight key points.

Complete 3 D now Or finish for homework. You should be studying for your test on Friday too

Sexual and asexual reproduction & variation