The correct answer is "limited prey is driving the bears to seek food in human settlements".
Due to the warming of the Arctic waters, the ice is melting, resulting in a serious decline of floating winter ice. Polar bears need these floating parts of ice to hunt, therefore this new situation limits the hunting opportunities of the bears. That is why polar bears are driven to human settlements to look for food.
Answer:
adenine pairs with Thymine and guanine always pairs with cytosine respectively
Explanation:
In DNA nucleotide subunits, there are four nitrogenous bases:
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
Each of these bases can be divided into two categories: purine bases and pyrimidine bases.
Adenine and guanine are examples of purine bases. This means their structure is a nitrogen-containing six atom ring joined with a nitrogen-containing five atom ring that share two atoms to combine the two rings.
Thymine and cytosine are examples of pyrimidine bases.
Note that RNA replaces thymine with a different pyrimidine base called uracil (U).
The complementary base pairing rule, Chargaff's rule states that DNA base pairs are always adenine with thymine (A-T) and cytosine with guanine (C-G). A purine always pairs with a pyrimidine and vice versa. However, A doesn't pair with C, despite that being a purine and a pyrimidine.
Answer:
The function of catalase is to protect cells from toxic effects by some reactive chemicals, such as hydrogen peroxide.
Explanation:
As a result of the metabolism, each organism causes some chemical substances to be produced, for example, hydrogen peroxide. Catalase catalyzes the reaction, decomposing hydrogen peroxide to compounds less dangerous for cells, for example, in water and oxygen. In the following reaction the function of catalase is shown:
2H2O2 -----------> 2H20 + O2
tree-species selection based on plant–animal interaction ..... visit it, but also on other plants visited by those animals and .... number and types of mutualistic partners.
Answer:
The circulatory system delivers oxygen and nutrients to cells and takes away wastes. The heart pumps oxygenated and deoxygenated blood on different sides. The types of blood vessels include arteries, capillaries and veins.
Explanation: