9. A class wanted to test the effect of increasing CO2 concentration on the amount of oxygen produced by photosynthesis. They placed elodea plants in 4 test tubes containing water at 25°C. They filled each tube with fresh
water. Test tube 1 received 0.6g of baking soda to supply CO2. Test tube 2 received 0.4g of baking soda Test tube
3 received 0.2g of baking soda. Test tube 4 received 0.0g of baking soda. A collection tube was placed over each
test tube to collect the oxygen gas. The light source was placed 30 cm away from the test tube.
a. What is the independent variable?
b. What is the dependent variable?
c. What is the control?
d. What are 2 constants?
e. If photosynthesis is occurring, should the amount of oxygen be increasing or decreasing? Explain.
3

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.