Answer:
a. hox genes.
Explanation:
HOX genes have the following functions:
- HOX genes are the homeobox subset.
- They specify the areas of the embryo's body plan along the animal head-tail axis.
- They are encoding Hox proteins that specify the position characteristics and ensure that the right structures form at the right position in the body.
- They regulate high-level executive genes, such as transcription factors and intracellular signaling molecules, which adhere, number, form, and growth to cells.
The vertebrates are highly preserved.
The clusters and other genes occur uninterrupted.
Evolutionary, the heterogeneous regulatory areas between the genes most previously present are larger and more preserved than those present at the other ends of the clusters.
The characteristical feature is that these are homeodomain proteins with a highly preserved area of DNA binding encoded with homeobox gens.
Answer:
1. hydrogen; 2
2. it means two strands of DNA twisted around each other like a winding staircase
In some types of research the target population might be as broad as all humans, but in other types of research the target population might be a smaller group such as teenagers, pre-school children or people who misuse drugs.
It is more or less impossible to study every single person in a target population so psychologists select a sample or sub-group of the population that is likely to be representative of the target population we are interested in.
This is important because we want to generalize from the sample to target population. The more representative the sample, the more confident the researcher can be that the results can be generalized to the target population.
One of the problems that can occur when selecting a sample from a target population is sampling bias. Sampling bias refers to situations where the sample does not reflect the characteristics of the target population.
