Categories
EVOLUTION

Darwin’s Theory Of Natural Selection.


Topic Darwin’s Theory of natural selection There are a few theories that attempt to explain or show how organisms change  (evolve)  over time  .ee
1.The Branching Theory.
2.The Theory Of Spontaneous Generation
3.  Use And Disuse.
4.The Theory Of Natural Selection.
Darwin’s theory of natural selection proposed that nature(the environment) is a major contributing factor of evolution.In other words organisms  with traits that help them survive in a changing environment ,will reproduce and pass on their traits to the next generation.A logical sequence of ideas explain this theory.
the power point presentation will help you understand how species change over time
Also you may read about the other proposed theories,check these  links:
     Khanacadmey.com
Wikipedia.com
you know that ,Darwin could not explain the genetic basis of variations.

 

Categories
EVOLUTION

Fossils, An Evidence Of Evolution


Hi, Do you have any questions about fossils? In the
following presentation you will be able to answer these questions
and learn how fossils are formed.

How can we use fossils as n evidence of
evolution
?
Types of fossils Where
can many fossils be found? How are sedimentary rocks
formed? Sedimentary rocks are formed from sediments such as rock
particles, silt, and mud. Name some of the fossils found in
SR.

   

Categories
EVOLUTION

Evollution


Evolution is the change in species over time,also known as biological or organic evolution.
1.What do scientist learn from the study of organic evolution?
1.The study of evolution helps to ,
1. Explain the differences in structure, function, and behavior among living things.
2.Explain the changes in characteristics in populations throughout time.
1.List the evidence that support the theory of evolution.
These evidences include, fossil records ,similarities in structure, embryo development,  cell structure,& chemical make up among organisms.

 

Categories
GENETICS LIVING THINGS

Inheritance of genetic traits


HSOffspring inherit their genetic traits that make them look like their parents, through  genes contained in the chromosomes during the process of reproduction.All body cells of an organism have identical genetic information,yet are different in structure and function.  The explanation for this variation in cellular structure,  is that  different  parts of the genetic  instructions are used in different cells and gene expression is  influenced by the cell environment and past history.

Check the power point presentation to get more information.

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Categories
LIVING THINGS

Steps Of The Reproductive Process In Humans


Well,you ,I And other humans followed  the same journey  to be here in this planet and play our role as humans. from a single cell at fertilization to a multi cellular  organism as baby at birth. follow the power point presentation to discover how you came to this world. don’t forget that some developed in a slightly different way.Can you tell how? well I will let you figure that by yourself.

 

Categories
LIVING THINGS

Types of fertilization


Fertilization is an essential process in sexual reproduction. It fuses the gametes thus restoring  the chromosomes number specific for the species.there are two types of fertilization,external and internal.

A quick warm up

1- Define fertilization.
The fusion or the union of sperm nucleus and an egg nucleus.

2- What is the importance of fertilization in sexual reproduction.?
It restores the chromosome # characteristic of the species.

Categories
GENETICS LIVING THINGS REPRODUCTION AND DEVELOPMENT

Embryonic Development


We Will follow the development of a fertilized egg from a zygote  to a baby. It’s fascinating to see how a single cell develops  and grows into a complete baby.

check your vocabulary through these introductory questions and follow the power point presentation to check your understanding of the process of development


Embryonic Development

How Does A Zygote develop into An Embryo?

Define the term embryonic development.

The changes from a zygote to a baby.

What will happen to the zygote after fertilization?

It undergoes the process of cleavage.

What is the end result of cleavage?

A  ball of cells called a morula is formed,then changed into a blastula.

 

Categories
LIVING THINGS REPRODUCTION AND DEVELOPMENT

Sexual Reproduction


Sexual reproduction:
Involves two parents.
Results in offspring that are different from either parent.
The genetic variation is due to recombination of chromosomes.
This process involves the fusion of two gametes nuclei (egg& sperm).
Fusion of the sex cell nuclei occurs during fertilization forming the zygote.

Check the details

Categories
GENETICS LIVING THINGS REPRODUCTION AND DEVELOPMENT

Meiotic cell division Meiosis


Facts about meiosis.

Meiosis involves two cell division.
It produces cells that are different from the parent cell. Each cell has .one-half the number of chromosomes as the parent cell.
Meiosis takes place during sexual reproduction, producing sex cells ( eggs & sperms ).
It takes place in the sex organs (ovaries & testes)

Let us explore how meiosis  happens.

Check the power point presentation.

Categories
LIVING THINGS

Active Transport Vs Diffusion (Passive Transport)


<a href="http://

https://www.fagcebook.com/Benguennak/posts/2077214812296410

“>Power point presentation All organisms must  absorb, and circulate nutrients through out the body,   All cells must  obtain the needed nutrients, to maintain homeostasis.Well, how does this transport of materials occur?

 

https://www.fagcebook.com/Benguennak/posts/2077214812296410


 <a href="http://PowerAll organisms must  absorb, and circulate nutrients through out the body,   All cells must  obtain the needed nutrients, to maintain homeostasis.Well, how does this transport of materials occur?  

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