Corn is one of the most important crops grown in the United States. Corn, which is mostly starch, is used as a food source for humans and other animals.
Humans first developed corn as a food crop over 8000 years ago. These early farmers produced corn by selectively breeding a wild grass called teosinte. The kernels of teosinte have a hard coating that makes them difficult for humans to eat. A key step in developing corn as a food crop was selecting individual plants that produced kernels without this coating so that they could more easily be used as a food source. The illustrations show the kernels on an ear of corn and the kernels on an ear of teosinte.
Corn and teosinte share the scientific name Zea mays. A single gene with two alleles codes for kernel coating (H) or no kernel coating (h) in Zea mays. To determine the inheritance pattern of this gene, scientists crossed teosinte that is true-breeding (homozygous) for kernel coating and domestic corn that is true-breeding for no kernel coating to produce offspring with partially formed kernel coatings. The three phenotypes and their genotypes are shown in the table.
This question has three parts.
Corn plants produce their own food through a chemical process.
Question 1
1.
Other Answer Choices:
Question 2
2.
Identify the source that provides energy for the chemical reaction in number 1 to occur.
Question 3
3.
Describe how human cells use the products from the chemical reaction in Number 1. Be sure to include the process that occurs at the cellular level.
Question 4
4.
Question 5
5.
Question 6
6.
Question 7
7.
Drag and drop a molecule into each box in the equation to show the chemical reaction corn plants use to make food. Each chemical symbol may be used once or not at all.
C6H12O6
H2O
CO2
O2
H2CO3
C3H8O3
Scientists crossed true-breeding corn and true-breeding teosinte to determine whether the plants produce fertile offspring. Which of the following questions was this experiment designed to answer?
Are corn and teosinte different species?
Do corn and teosinte both use seeds to reproduce?
Can corn and teosinte plants grow in similar environments?
Do corn plants contain more dominant alleles than teosinte plants do?
A student claims that the inheritance pattern for kernel coating is incomplete dominance.
Which of the following pieces of evidence best supports the student’s claim?
Corn and teosinte share the scientific name Zea mays.
Early farmers produced corn by selectively breeding teosinte.
A single gene with two alleles codes for the presence or absence of kernel coating in Zea mays.
The cross between domestic corn and teosinte produced offspring with partially formed kernel coatings.
Scientists studied reproduction in corn and teosinte.
Select two types of cells that combine to produce offspring when a corn plant is crossed with a teosinte plant.
egg
leaf
root
stem
sperm
Corn kernels are fertilized seeds that develop into corn plants after they are planted. How does the number of chromosomes in a corn kernel cell compare to the number of chromosomes in the body cell of a corn plant?
A corn kernel cell has half as many chromosomes as the body cell because the kernel is a gamete.
A corn kernel cell has the same number of chromosomes as the body cell because the kernel developed from a zygote.
A corn kernel cell has twice as many chromosomes as the body cell because the kernel developed from two corn plants.
A corn kernel cell has no chromosomes and the body cell has a full set of chromosomes because chromosomes are produced as the corn plant grows.
