Answer:
C
Explanation:
Without crossing over, each chromosome would be either maternal or paternal, greatly reducing the number of possible genetic combinations, which would greatly reduce the amount of genetic variation between related individuals and within a species.
Answer:
Option C, Plant A
Explanation:
Control group within an experiment is the substance/organism or subject which shall enact as a base for comparison of impact of experiment created on the dependent variables.
Here, the impact of fertilizer is to be studied on plant. Thus, plant set up is dependent variable and amount of fertilizer is an independent variable. Out of all plants one plants is getting 0 amount of fertilizer hence this plant can be used for comparison with other plants which receives the fertilizers.
d. O2
This is because CO2 (Carbon Dioxide), energy (sunlight), and H2O (water) are all outputs of cellular respiration.
The question is incomplete. Th ecomplete question is as following:
All of the following protect the skin and mucous membranes from infection EXCEPT
A) multiple layers of cells.
B) tears.
C) saliva.
D) HCl.
E) the "ciliary escalator."
Answer: D) HCl.
Explanation:
- The epidermis, the outer layer of the skin provides waterproofing and serves as a barrier to infection and other laers also sustain any type of injury.
- Tears wash out foreign bodies which enter the eye. In addition, tears contain a substance called lysozyme which has an antibacterial function and works to prevent microbial invasion and infection.
- Saliva protects against infection, especially via the innate immune system. This mechanism is an important first-line protection against bacterial and viral infection
- The mucociliar escalator is within the conducting airways and is composed of mucus and cilia that transfer the mucus up and out of the lungs where it can be removed by coughing or swallowing,
Whereas HCL helps in the digestion process.
Hence, the correct option is D.
