Hikers who found a human body at high altitude in the Italian Alps thought the man had died recently, but tests indicated he was shot with an arrow more than 5,300 years ago.

Which of the following would be the best reason for prolonged preservation of the body? .

ff.

In this cross, both parents are homozygous recessive for the smooth leaf trait

(ff).

This means that all of their offspring will inherit two copies of the recessive allele (f) and will therefore have smooth leaves.

Choice A.

FF x FF is not correct because both parents are homozygous dominant for the fuzzy leaf trait (FF) and all of their offspring will inherit two copies of the dominant allele (F) and will therefore have fuzzy leaves.

Choice B.

Ff x Ff is not correct because both parents are heterozygous for the leaf trait (Ff) and their offspring can inherit either one dominant allele (F) or one recessive allele (f) from each parent, resulting in a 3:1 ratio of fuzzy to smooth leaves. Choice D.

Ff x ff is not correct because one parent is heterozygous for the leaf trait (Ff) while the other is homozygous recessive (ff), resulting in a 1:1 ratio of fuzzy to smooth leaves in their offspring.

Melanin.

Melanin is a pigment produced by cells called melanocytes in the skin.

It protects the skin from ultraviolet (UV) radiation by absorbing and dissipating over 99.9% of absorbed UV radiation.

This helps to prevent DNA damage and other adverse effects of UV radiation on the skin.

Choice B.

Perspiration is not correct because it is a fluid produced by sweat glands in the skin that helps to regulate body temperature, but it does not protect the skin from UV radiation.

Choice C.

Sebum is not correct because it is an oily substance produced by sebaceous glands in the skin that helps to lubricate and protect the skin, but it does not protect the skin from UV radiation.

Choice D.

Keratin is not correct because it is a fibrous protein that provides strength and durability to the skin, hair and nails, but it does not protect the skin from UV radiation.

Plasma B cells.

Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells).

When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone.

The mature B cells, called plasma cells, secrete millions of antibodies into the bloodstream and lymphatic system.

Choice A, Natural killer cells, is not the correct answer because natural killer cells are a type of white blood cell that play a major role in the host-rejection of both tumors and virally infected cells.

Choice B, Cytotoxic T-cells, is not the correct answer because cytotoxic T-cells are a type of white blood cell that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways.

Choice D, Helper T-cells, is not the correct answer because helper T-cells are a type of white blood cell that play an important role in the immune system by helping other white blood cells fight infections.

Triple point.

In a phase diagram, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously is the triple point.

The triple point is a unique point on a phase diagram where the three states of matter (solid, liquid, and gas) can coexist in equilibrium.

At the triple point, the temperature and pressure of the substance are fixed.

Option B, critical temperature, is the temperature at which a gas cannot be liquefied, regardless of the pressure applied.

It is a characteristic property of a substance and is typically higher than the boiling point of the liquid at standard pressure.

Option C, critical point, is the point on a phase diagram where the liquid and gas phases of a substance become indistinguishable.

At the critical point, the distinction between the liquid and gas phases disappears, and the substance becomes a supercritical fluid.

Option D, absolute zero, is the theoretical temperature at which all matter has zero thermal energy.

At absolute zero, all substances are in their solid state, but it is not relevant to a phase diagram, as it is a temperature where no transitions between states occur.

In summary, the term used for a substance held at a temperature and pressure where the solid, liquid, and gaseous states of a substance exist simultaneously in a phase diagram is the triple point, whereas the other options provided are not relevant or are characteristic properties of substances in different contexts.

Diffusion down a concentration gradient causes most of the carbon dioxide from the blood to move into the alveoli.

The alveoli are tiny air sacs in the lungs where gas exchange occurs.

Carbon dioxide is a waste product of cellular respiration and is carried by the blood to the lungs to be exhaled.

In the lungs, carbon dioxide diffuses from the blood (where its concentration is high) into the alveoli (where its concentration is lower) down its concentration gradient.

Choice A is incorrect because carbon dioxide is not converted to carbon monoxide in the body.

Choice C is incorrect because passive transport using carrier proteins is not the primary mechanism by which carbon dioxide moves from the blood into the alveoli.

Choice D is incorrect because active transport using energy is not involved in the movement of carbon dioxide from the blood into the alveoli.

In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, while cytosine (C) and guanine (G) pair together.

Therefore, the complementary strand of the given DNA sequence 3' TCGATCGCA 5' would have the complementary nitrogenous bases as:

5’ AGCTAGCGT 3’

NOTE: The 5’ to 3’ direction of the complementary strand is opposite to that of the given strand.

Choice A.

3’ AGCTAGCGT 5’ is not correct because it is not complementary to the given strand.

Choice C.

5’ UCGAUCGCA 3’ is not correct because it contains uracil (U), which is a nitrogenous base found in RNA, not DNA.

Choice D.

3’ TCGUTCGCU 3’ is not correct because it also contains uracil (U), which is a nitrogenous base found in RNA, not DNA.

A decline in osteoblast activity while osteoclast activity continues at expected levels results in osteoporosis.

Osteoporosis is caused by an imbalance between the functioning of osteoclast and osteoblast cells.

Osteoblasts are responsible for forming new bone, while osteoclasts break down old bone.

If osteoblast activity declines while osteoclast activity continues at expected levels, this means that more bone is being broken down than is being formed, leading to a loss of bone density and an increased risk of osteoporosis.

Choice A is incorrect because an increase in osteocyte activity would not result in osteoporosis.

Osteocytes are mature bone cells that maintain the mineral concentration of the bone matrix.

Choice B is incorrect because a decline in osteoclast activity would not result in osteoporosis.

Osteoclasts break down old bone, so a decline in their activity would mean that less bone is being broken down.

Choice C is incorrect because an increase in osteocyte activity would not result in osteoporosis.

As mentioned earlier, osteocytes are mature bone cells that maintain the mineral concentration of the bone matrix.

Heavier objects fall faster than lighter objects.

The data in the table shows that as the number of filters (and therefore the mass) increases, the terminal velocity also increases.

This means that the heavier objects (with more filters) are falling faster than the lighter objects (with fewer filters).

Choice A is not supported by the data in the table as much as it is true.

Terminal velocity is indeed when the force of gravity is equal to air resistance, but this definition does not provide any information about the relationship between mass and terminal velocity.

Choice B is also not supported by the data in the table.

The data does not provide any information about the time it takes for an object to reach terminal velocity.

Choice D is not supported by the data in the table.

The data shows that as the number of filters increases, the terminal velocity also increases.

This means that the greater the number of filters, the greater (not smaller) the terminal velocity.

As a solid turns to a liquid, the particles become less ordered and more free to move around.

Choice B is not correct because particles have an increase in mobility as a solid turns to a liquid.

Choice C is not correct because particles move further apart as a solid turns to a liquid.

Choice D is not correct because intermolecular forces between particles become weaker as a solid turns to a liquid.

Bag mass change is the dependent variable in this experiment.

In an experiment, the dependent variable is the variable that is being measured and is expected to change in response to changes in the independent variable(s).

In this case, the bag mass change is being measured and is expected to change in response to changes in the independent variable (sucrose concentration).

Choice A is incorrect because duration is not a variable in this experiment.

Choice B is incorrect because temperature is not a variable in this experiment.

Choice D is incorrect because sucrose concentration is an independent variable, not a dependent variable.

An independent variable is a variable that is manipulated by the experimenter to see how it affects the dependent