Read the text: Trans fat is obtained industrially after certain vegetable oils, under certain conditions, are hydrogenated and transformed into solid fat. This type of fat has been used in the production of some food products, such as stuffed cookies, giving them, for example, a more crunchy consistency. However, it is admitted that the excessive consumption of trans fat contributes to obesity and the development of cardiovascular diseases. a) What group of lipids do oils and fats belong to? b) How can we differentiate oils from fats at room temperatures, around 20 ° C? c) Many seeds, such as soybeans, store relatively large amounts of oil. What is the importance of the presence of oil for the embryo of oil seeds? d) Birds and mammals store fats in adipose tissue, under the skin. What is the advantage of the fatty layer under the skin being especially developed in animals that live in cold climates, such as polar bears? e) Recent studies indicate that fat is associated with cardiovascular disease. Name another substance in the lipid group also commonly associated with these diseases.

Answer and Explanation:

a) What group of lipids do oils and fats belong to? Lipids and fats belong to the triglyceride group. Triglycerides are a mixture of glyceride esters and fatty acids. They are stored in specialized adipose cells, known as adipocytes. Adipocytes give a place to the adipose tissue in the organism.  

b) How can we differentiate oils from fats at room temperatures, around 20 ° C? At room temperature, fats can be recognized for being solid, while oil is liquid.

c) Many seeds, such as soybeans, store relatively large amounts of oil. What is the importance of the presence of oil for the embryo of oil seeds? The plant´s embryo needs to nurture while it is developing. The oil in the seeds plays the role of nutritive storage, together with other nutritive substances. These are used by the plant until it is able to photosynthesize.

d) Birds and mammals store fats in adipose tissue, under the skin. What is the advantage of the fatty layer under the skin being especially developed in animals that live in cold climates, such as polar bears? The advantage of the fatty layer under the skin is to keep or maintain the animal´s temperature. It is very common to find a thick fatty layer under the skin of animals that live in very cold environments, such as polar bears or deep divers marine mammals.

e) Recent studies indicate that fat is associated with cardiovascular disease. Name another substance in the lipid group also commonly associated with these diseases. Cholesterol is a fatty substance needed for the good functioning of the organism. It is part of cellular layers and it plays a role in hormone synthesis and biliary salts. Although in excess they might be harmful as they tend to accumulate in the artery´s walls, blocking the passage of blood. This can lead to a heart attack.

the answer is c) an oak tree

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.