X

Download Natural Selection In Action PowerPoint Presentation

SlidesFinder-Advertising-Design.jpg

Login   OR  Register
X


Iframe embed code :



Presentation url :

Home / Health & Wellness / Health & Wellness Presentations / Natural Selection In Action PowerPoint Presentation

Natural Selection In Action PowerPoint Presentation

Ppt Presentation Embed Code   Zoom Ppt Presentation

PowerPoint is the world's most popular presentation software which can let you create professional Natural Selection In Action powerpoint presentation easily and in no time. This helps you give your presentation on Natural Selection In Action in a conference, a school lecture, a business proposal, in a webinar and business and professional representations.

The uploader spent his/her valuable time to create this Natural Selection In Action powerpoint presentation slides, to share his/her useful content with the world. This ppt presentation uploaded by dixitdeep12 in Health & Wellness ppt presentation category is available for free download,and can be used according to your industries like finance, marketing, education, health and many more.

About This Presentation

Natural Selection In Action Presentation Transcript

Slide 1 - Natural Selection in Action Higher Biology
Slide 2 - Natural Selection in Action Most mutations produce inferior versions of original gene Some mutations allow adaption to a changing environment Mutant allele gives mutant form of organism a selective advantage Change in environment -abiotic factor (e.g. pollution) -biotic factor (e.g. disease)
Slide 3 - Sickle cell anaemia Genetically transmitted disease of the blood Caused by presence of abnormal haemoglobin S Abnormality occurs as result of mutation
Slide 4 - Haemoglobin S H – allele for normal haemoglobin S – allele for haemoglobin S People homozygous for mutant allele (SS) -sickle-shaped red blood cells -inefficient at carrying oxygen -cells clump together interfering with circulation
Slide 5 - ppt slide no 5 content not found
Slide 6 - Symptoms of Sickle Cell Anaemia Fatigue Breathlessness rapid heart rate delayed growth and puberty susceptibility to infections ulcers on the lower legs (in adolescents and adults) jaundice attacks of abdominal pain weakness joint pain fever Vomiting bloody (hematuria) urination excessive thirst excessive penis pain Priapism chest pain decreased fertility
Slide 7 - Incomplete dominance Allele H incompletely dominant to allele S Heterozygotes – HS Allele S partially expressed Sickle Cell Trait -a third of the haemoglobin is S
Slide 8 - Sickle Cell Anemia in Africa Allele S rare in populations as semi-lethal Some parts of Africa up to 40% of population is HS People with Sickle Cell Trait resistant to malaria
Slide 9 - Distribution of malaria Distribution of sickle cell trait
Slide 10 - Sickle Cell Trait and Malaria In malarial regions -natural selection favours people with genotype HS People that are HH will die during serious outbreaks of the disease Hs loses selective advantage in non-malarial sites
Slide 11 - Industrial Melanism in Peppered Moth Two forms of Biston betularia (peppered moth) (melanic)
Slide 12 - Biston betularia Differ by only one allele of the gene forming dark pigment (melanin) Both forms fly by night Both forms rest on trees during the day
Slide 13 - Prior to Industrial revolution Pre 1800s Light form common throughout Britain Dark arose by mutation -very rare
Slide 14 - Light peppered moths In non-polluted areas -tree trunks covered with pale coloured lichens Moth well camouflaged against pale background Dark form easily seen and eaten by predators
Slide 15 - Survey in the 1950s Pale form most abundant in non-industrial areas Dark forms most abundant in areas suffering from heavy air-pollution
Slide 16 - Reason for change? In polluted areas -toxic gases kill lichen -soot particles darken tree trunks Dark coloured well hidden and favoured by natural selection Light coloured moth easily seen
Slide 17 - Frequencies of two forms of peppered moths in the 1950s
Slide 18 - This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.