I have a few biology questions! 2. What statement about crossing-over is true?
a. The genetic variability of the off spring is reduced.
b. It occurs during meiosis.
c. Genes located far apart on a chromosome are less likely to be separated.
d. It occurs between chromosomes that are NOT homologous.

4. The lac genes are turned off when
a. lactose is present.
b. RNA polymerase binds to the promoter.
c. the repressor binds to the operator.
d. RNA polymerase binds to the repressor.

10. Which of the following is NOT a factor that affects photosynthesis?
a. temperature
b. water availability
c. light intensity
d. heterotroph availability

12. In the Krebs cycle, pyruvic acid is
a. generated so that glycolysis can continue.
b. broken down into carbon dioxide.
c. used to convert ATP into ADP.
d. broken down into glucose.

Hey me with this one❤❤❤❤ every organism needs food. does a cell also need it? explain very briefly.

Rease is an enzyme used by plants to break down urea (a nitrogen-containing compound) into carbon dioxide and ammonia. urease urea > > > carbon dioxide and ammonia ammonia is broken down by plants into a nitrogen source plants need to grow. thus, plants could not use urea as a nitrogen source unless it was first converted to ammonia. in soybean plants there are two different kinds of urease, one produced in the seeds and the other produced in the leaves of the plant. three types of soybean plants were used in a set of experiments: normal soybeans and two mutant strains, one lacking the urease in the seeds only (strain 1) and one lacking urease in the leaves only (strain 2). experiment 1 separate areas in a field were planted with normal, strain 1, and strain 2 soybeans. all types of soybeans appeared to grow, flower, and produce seeds equally well. there were no externally detectable differences among the strains. experiment 2 small pieces of plant leaves of equal weight were obtained from each type of soybean plant and separately placed on media in culture dishes. tissue growing in this way will become an unorganized clump of cells referred to as callus. to provide a controlled nitrogen source, half the tissue samples of each type were placed on media containing urea, and the other half of the samples were placed on media containing ammonia. after 30 days, the weight gain for each of the callus samples was determined. results are shown in the table below.

You are observing different types of cells in your science lab. one cell has many chloroplasts. what is the most likely function of this cell? a. energy production b. photosynthesis c. reproduction d. digestion