Heredity Review

#Heredity By: Calvin W.

Punnett Square

     The two genotypes are the contribution of one parent, and the contribution of the other parent.  In this case G=green flowers and g=yellow flowers.  The possible outcomes are either green or yellow flowers, but there is GG, with two dominant alleles, Gg with one dominant and one recessive allele, and gg, with two recessive alleles.  There is a 75% chance that the flower will be green.  You have two homozygous outcomes, and two heterozygous outcomes.

Same species, different color.

     Offspring that result from sexual reproduction are more likely to have more diverse characteristics than offspring that result from asexual reproduction because asexual reproduction is just a clone of the original species, so it only inherits genes from one parent. With sexual reproduction, offspring inherit genes from both parents.


1. Adaptation: An inherited behavior or physical characteristic that helps an organism survive and reproduce in its environment.

2. Evolution: Change over time; the process by which modern organisms have descended from ancient organisms

3. Species: A group of similar organisms that can mate with each other and reproduce offspring that can also mate and reproduce.

4. Gene: A sequence of DNA that determines a trait and is passed from parent to offspring.

5. Genetics: The study of heredity

6. Sexual Reproduction: The production of new living organisms by combining genetic information from two individuals of different types (sexes).

7. Asexual Reproduction: A form of reproduction from which offspring arise from a single organism, and inherit the genes of that parent only.

                                   Below is the classification of animals

Animal Classification

                                     This is the classification of a Polar Bear.

Classification of Polar Bear

     Some genetic variations make individuals better adapted to the environment.  Those individuals are more likely to survive and reproduce.  Their offspring mat inherit the helpful characteristic.  The offspring in turn will be more likely to survive and reproduce, and pass the characteristic to their offspring.  After many generations, more members of the species will have that helpful characteristic.  In effect, the environment selects organisms with helpful traits to become parents of the next generation.  Darwin proposed that, over a long time, natural selection can lead to change.  Helpful variations may accumulate in a species, while unfavorable ones may disappear.

Charles Darwin