When a foetus is formed, it has 2 sex chromosomes which decide if the foetus will be male or female. XX chromosomes give a female individual and XY chromosomes give a male. Initially, a foetus is bipotential but at about 6 weeks, the chromosomes ´switch on´ and the testes start to develop. As they develop, they release sex specific hormones. The testes release testosterone and the ovaries release oestrogen.
The article, “His Brain, Her Brain” By Larry Cahill describes the research that has been carried out and is ongoing into differences between male and female brains. The is no longer considered a sexist claim, because there are differences, not only in the structure of male and female brains, but in the way different areas of the brain react to various stressors. Back in 1966, Scientific American published an article which described how sex hormones directed divergent reproductive behavior in rats, which was thought to be controlled by the hypothalamus. This led to scientists believing that sex differences in the brain referred to mating behavior, sex hormones, and the hypothalamus. With the development of new imaging techniques
The Amniotic Sac also develops, which is a fluid-filled membrane that supports the developing fetus. During the First Trimester, the child will develop limb buds, which are the beginning of the arms and legs, along with developing; fingers, toes, ears, ankles, wrists, and eyelids. The child’s heart will begin to beat around the 25th day after conception. The child also begins to develop all of its major organism, and its neural tube, which connects the brain to the spinal cord. Usually home pregnancy tests are accurate after the first day of a woman's missed period.
John B. Watson and Rosalie Rayner – Little Albert Experiment The aim of the experiment was to investigate whether fear can be acquired through classical conditioning on human beings. Before conditioning, pre-testing was done to see if Albert was capable of producing a fear response. The checked if he was afraid of different materials, such as: a white rat, a rabbit, a dog, a monkey, masks with and without hair, cotton wool, burning newspapers, etc but he demonstrated no fear. They found that little Albert showed fear when exposed to loud noises. They started conditioning by showing Albert a white rat.
Hence it is always the male who determines the sex of the child. For the first 7 weeks of development, the external genitalia appears identical in both sexes. Internally, the same two sets of ducts develop in both males and females. After 7 weeks the differentiation between the sexes begin. The presence of the Y chromosome induces the developing gonads to produce hormones, including testosterone , which stimulate the development of the male internal reproductive system.
Rodents also act as long term preservers for plague. Any rat bit by an infected flea would spread it to all the other fleas that bite it. This could cause it to spread around really fast. Rodents probably play the biggest roll in spreading plague around. The bubonic plague could also be very hard to detect.
Mrs. Frisby and the Rats of NIMH created a strong feeling on individuals. Most likely because individuals considered that someplace in this world mice and rats might actually be up amazing like this. Having re-read it as an adult, individuals observe currently that sensible and unsentimental style of writing of Robert C O'Brien creates it all appear probable (Charlotte, 1998). Although they recognized the conclusion, they still discovered themselves drawn into the story from begin to end and entirely won over through the rodents of the title. Mrs. Frisby, a mouse, is attempting to watch out of her children on her individual since her husband was eaten through the cat of farmer, Dragon.
B.F. Skinners contributions to the psychological world were great in theory and action. The last thing that B. F. Skinner was learning was that, to speed up the response acquisition during operant conditioning is to reinforce successive approximations to desired responses. This approach was called shaping. We might first reward the rat for turning toward the response bar. Once the rat has learned this behavior, we might withhold reinforcement until the rat moves towards the bar.
One of the causes that brought about the differences in alleles is sexual reproduction during meiosis. There are two main events during meiosis, crossing over of chromatids and independent segregation of chromosomes. During meiosis I, homologous pairs of chromosomes come together and pair up. The chromatids twist around each other and bits of chromatids swap over, the crossing over of chromatids in meiosis I means that each of the four daughter cells formed from meiosis II contain chromatids with a different set of alleles, which increases genetic variation. Meanwhile during the independent segregation of chromosomes, half of your chromosomes come from your mum (called maternal chromosomes) and half from your dad (called paternal chromosomes).
Assignment: Gender Identity Colleen Rabe Course: PSY 265 Due Date is week 3 day 7 There several factors that are used when determining gender identity. These include genetic factors, environmental situations, psychosocial factors, and even sexual hormones. “Gender identity is almost always consistent with chromosomal sex.” From the moment sperm fertilized an ovum, our destiny to be a girl or a boy is chosen. Usually at this chromosomes from the male donor and from the female come together and combine to make a “zygote”. Starting about six weeks into the pregnancy, our bodies began to form and create the sex of what they are meant to be.