Reproductive and Heredity
There are two distinct ways in which species reproduce, either through sexual reproduction or asexual reproduction.
Asexual reproduction can be found in some species, here the offspring produce are identical in nature to their parent.
In sexual reproduction, offspring inherits trait from both parent through sex cells which consists of sperm and ova. These sex cells combine to form unique characteristics from both parents cell which are therefore transfer to the offspring. Note that, the process whereby physical characteristics of an organisms which is known as trait is transferred from parent to offspring in sexual reproduction, is called Heredity.
Gregor Mendel (1822-1884) was the first man to study heredity. He experimental by observing purebred pea plants. He discovered those purebred plants that are short produce offspring that short. Then he decided to experiment by crossing purebred plants that are short with the tall ones. The result was that in the first generation of the offspring the purebred plant produces tall offspring only. When the tall generations of offspring reproduce, about three quarters of the next generation were tall and one quarter were short, and at the stage the purebred plant that are short were reproduce. He repeated the same process and come to a conclusion that an offspring plant could inherit one trait from the male parent and another from the female parent and that one could hide the other trait.
In heredity, traits are being control by genes. These genes control the height of plants. The different forms of gene are called alleles which indicate the alleles for tallness and alleles for shortness which are inherited from each parent.
Lastly, the dominant allele (the tallness allele) controls the appearance of the trait, while the recessive allele (the shortness allele) is hidden. Note: for a recessive trait to occur in an individual that individual must inherit two recessive alleles.
Questions
From the above what are the chances that an offspring will be tall? A. 1 out of 4 B. 3 out of 4 C. 2 out of 4 D. None
Ans= B
- The factors that control traits are called…………….? A. Alleles B. Purebred C. Dominant allele D. Genes
Ans= D
- If a pea plant is being planted in the garden. To grow tall pea plants which of the following genotype is needed? A. Tt B. tt C. TT D. tT
Ans= D
- in asexual reproduction, an individual organism produces offspring that are ……………. To the parent. A. Different B. Unique C. Identical D. Special
Ans= C
- Mendel in is experiment make use of …………………… pea plant A. Sparkling B. Golden C. Well organize D. Purebred
Ans= D