Study notes When designing an efficient accurate experiment you should always have a control group. When measuring and recording the height of plants over a period of time scientist will tend to use line graphs. The nucleus of a cell directs all the cell’s activities. To calculate the mean add all the values together and divide by the number of values. Bones make blood cells, protect organs and store calcium. The liver, stomach, small intestines and pancreas are related to each other in their function and make up the digestive system. Scientists repeat their experiments before drawing conclusions. Tropical rainforests have warm temperatures throughout the year, heavy rainfall and a lot of decomposers.

Plants grow when they have optimum (the best/right) amounts of the things they need: sunlight, water, warmth etc. Mitochondria and chloroplasts are similar because they both help make energy available for cells to use. When organizing multicellular organisms into levels (least complex to most complex) organs would come between tissues and organ systems. The nervous system receives stimuli, transmits information to the spinal cord and to the brain. Farmers used selective breeding to develop domestic breeds of animals we rear today including chickens, turkey and pigs. When a gene is dominant it is always expressed in the organism’s phenotype (what it looks like). After nutrients are absorbed by the small intestine, they are absorbed into the blood and move through the circulatory system to the cells.

Mitochondria produce energy for the cell. More mitochondria = more energy. Blood is considered a tissue because it is composed of red and white blood cells working together and having specific functions. After we exercise our bodies feel tired because our muscles are fatigued from being used for a long time. Chloroplasts are found in plant cells. Chloroplasts give leaves their green color. After exercising the heart takes about 10 minutes to return to its normal rate. Specialized cells that are similar in structure and function are usually joined together to form tissues. When we calculate the possible off spring of two heterozygote organisms (ex. Rr) using a Punnet square our results will be: 25% RR, 50% Rr and 25% rr. An organism that reproduces through asexual reproduction has only one parent. Of the following cell, tissue, organ and organ system the cell is the most primary or basic. Phenotype such as the color of a dog’s fur is inherited from the parents.

The number of chromosomes in a human body cell is twice as much as the number of chromosomes in a human egg cell. The circulatory system carries oxygen to the cells, carries carbon dioxide away from the cells, carries food to the cells and carries waste products away from the cells. When a cell undergoes mitosis the two resulting cells have the same number of chromosomes as the original cell. If an individual catches an infectious disease the circulatory system and the lymphatic system work together to heal the individual. Chloroplasts and mitochondria are 2 energy producing organelles in plants. The arrows in a food chain or food web show the flow of energy. The energy from the mouse is transferred to the snake when the snake eats it. Mouse  snake

Gas exchange, diaphragm, and inhale are most closely associated with the respiratory system. When scientists are conducting research and doing experiments they need to keep very accurate records of all their results. When an organism’s food source is depleted the population will decrease because they have less prey. The tropical savannah biome has a dry climate and is occupied by elephants, giraffe, lion and zebra. All the energy in a food web comes from the sun. The esophagus carries food from the mouth to the stomach. If pesticides are applied to a lawn they kill insects and the animals that eat insects will decrease due to lack of food. An experiment usually has three kinds of variables: independent, dependent, and controlled. The independent variable is the one that is changed by the scientist. From smallest to largest we would arrange parts of the digestive system as follows: stomach cells, stomach muscles, stomach and digestive system.