Answer:
The model is inaccurate because the base pairs are incorrect.
Explanation:
The model of DNA that the student made was:
G-G
A-A
T-T
C-C
G-G
A-A
T-T
C-C
The model is pairing the bases incorrectly since guanine (G) forms a base pair with cytosine (C) and adenine (A) with thymine (T). In other words, the bases do not pair with the same type.
The DNA strands, which have deoxyribose, phosphate groups, and different bases, are together thanks to hydrogen bonds between the pairs. The pair G-C has three hydrogen bonds, while the pair A-T has two hydrogen bonds.
Answer:
The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients (such as amino acids and electrolytes), oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.
There are two main types of circulatory systems: 1. open circulatory systems and closed circulatory systems. Open circulatory systems are systems where internal organs and body tissues are surrounded by circulatory fluid. This fluid is called hemolymph, and it's pretty much like blood, except that it doesn't contain oxygen transporting cells.
2. The closed circulatory system of some mollusks and all vertebrates and higher invertebrates is a much more efficient system. Here blood is pumped through a closed system of arteries, veins, and capillaries. Capillaries surround the organs, making sure that all cells have an equal opportunity for nourishment and removal of their waste products. However, even closed circulatory systems differ as we move further up the evolutionary tree.
The primary function of chloroplast is to carry out photosynthesis with the help of chlorophyll.
Answer: The correct option is D(Some produce toxic agents in the water).
Explanation:
Dinoflagellates are found in the phylum Dinoflagellata which are single celled organisms. They are mostly found in the ocean while few of them can live in streams, freshwater ponds and rivers. The following characteristics can be used to identify a Dinoflagellates, these include:
--> they are golden brown
--> they possess assimilative cell with indented waist.
--> they possess large nucleus with visible chromosomes.
It has been reported that many dinoflagellate species can produce various natural toxins. These toxins can be extremely toxic and many of them are effective at far lower dosages than conventional chemical agents. Therefore the option, Some produce toxic agents in the water, is a correct statement.