Ramanpreet Kaur Sandhu's Podcast

Biology: The Human Brian

Ramanpreet Kaur Sandhu — Wed, 06 Jul 2011 07:35:35 +0000

The brain has four main parts to it the medulla oblongata, cerebrum, cerebellum, and hypothalamus. The lowest part of the vertebrate brain, commonly called the medulla; a swelling of the hindbrain dorsal to the anterior spinal cord that controls autonomic, homeostasis functions, including breathing, heart and blood vessel activity, swallowing, digestion, and vomiting. The medulla oblongata is located at the last part of the brain, just above the spinal cord. There are three vital centres are located in the medulla such as cardiac centre, respiratory centre, and vasomotor centre. The function of the cardiac centre is to regulate heartbeat. The respiratory centre regulates the rate and depth of breathing. The Vasomotor centre is which regulates blood pressure by controlling the diameter of blood vessels. Also, the medulla oblongata has mini centres of some reflex actions such as swallowing; sneezing, hiccupping, and vomiting are located in the medulla as well. The second major part of the brain is the cerebrum it functions to storage of memory and emotions. The third part is cerebellum functions in unconscious coordination of movement of movement and balance. Its shape liked a butterfly and functions to coordinate complex muscle movement (makes movements smooth, not jerky); responsible for hand- eye coordination (eg catching a ball) and maintains balance and posterior. Lastly is the hypothalamus its function in maintaining homeostasis, especially in coordinating the endocrine and nervous system: secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary. It is very important to have all these 4 parts in order to live as a normal human being.

Plant Reproduction

Ramanpreet Kaur Sandhu — Wed, 06 Jul 2011 06:32:59 +0000

In my biology class we also learned about how plants reproduce. There are two types of reproduction sexual and asexual reproduction but most plants reproduce asexually. The form of sexual reproduction in plants is often called vegetative reproduction. It involves the production of genetically identical offspring from one parent. In fragmentation a part of the parent plant is broken off or cut off. This piece then develops into a new individual. This is common in the propagation of many house plants. For example just one leaf from an African violet can generate a whole new plant. Another method of asexual reproduction is called budding. When budding the cell or parent organism divides unequally, when attached the smaller portion develops into a new organism and subsequently separates or breaks off from the parent and exists as a separate individual. Another method of asexual reproduction is similar to parthenogenesis in animals. In this new individuals develop from unfertilized eggs. Dandelions are examples of a plant that sometimes will reproduce this way. There are several other methods of asexual reproduction in plants which involve modification of one or more plant organs, like stems. Some Examples are rhizomes, tubers, corns, bulbs and stolens (which are also called runners).

Biology: General Reproductive

Ramanpreet Kaur Sandhu — Wed, 06 Jul 2011 05:46:24 +0000

Reproduction was a topic we covered comprehensively. The ability to reproduce is a characteristic for all living things. All organisms are composed of one or more cells. In order for reproduction to occur new cells must be produced from previously existing cells. In Eukaryotes there are 2 different ways cells produce new cells. They are called mitosis and meiosis. When eukaryotic cells divide the new cells must carry the genetic information which is found in the nucleus in structures called chromosomes. Mitosis and meiosis are both types of cell divisions which ensure that the daughter cells receive the proper amount of genetic information, that is the correct number of chromosomes. Haploid cells contain only one copy of each chromosome. Diploid cells contain two copies of each chromosome, one copy coming from each of its parents. In mitosis one cell divides to form two daughter cells. Through mitosis the two cells produced are genetically identical to the parent cell and also to one another. Meiosis is a type of division by which a diploid cell, having two copies of each chromosome gives rise to four haploid cells having just one copy of each chromosome. In meiosis the four daughter cells are each genetically different from each other and genetically different from the original cell. Both haploid and diploid cells can undergo mitosis but only diploid cells can undergo meiosis.