Biology: the difference between a rhizoid and a rhizome

The tutor visits the distinction between the similar-sounding structures rhizoid and rhizome.

Rhizoids are simple structures that resemble roots but are are more primitive. They provide anchorage and some absorption of water and nutrients. Fungi and mosses have rhizoids in place of actual roots.

A rhizome is a structure found in a plant that has true roots. Ironically, though found underground, a rhizome is a specialized stem, rather than a root. The potatoes we eat are rhizomes.

Source:

Mader, Sylvia. Inquiry into Life, 9th ed. Toronto: McGraw-Hill, 2000.

Ritter, Bob et al. Biology, BC ed. Scarborough: Nelson, 1996.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Fungi: reproductive cycle: zygospore fungi

The tutor comments about the reproductive pathways of zygospore fungi, including black bread mold.

With a zygospore fungus, such as black bread mold, the part you see above the surface comprises sporangia (singular: sporangium), which release spores. Spores have n chromosomes; they are haploid. Spores are released into the air. If a spore lands in welcoming conditions, it undergoes mitosis and develops into a new adult.

The more common situation is asexual reproduction, in which a single adult produces spores that repeat its own genetic signature.

Below the surface, the nonreproductive structures are the hyphae, which root throughout the growth medium (bread, for example). Zygospore fungi don’t have male and female individuals, but rather minus and plus. When hyphae from a minus and a plus touch, sexual reproduction occurs. First, each side forms a gametangium at the contact site. Inside each gametangium, gametes are produced. The two gametangia join externally, then, internally, their gametes fuse, forming zygotes, which are diploid (2n). The body in which the zygotes are encased develops a tough protective wall; it’s called a zygospore. This structure can endure adversity until favourable growth conditions resume.

When the zygospore detects promising growth conditions, meiosis occurs within. Then, the new haploid cells undergo mitosis in order to develop new adult bodies from which sporangia develop.

The life cycle described above is haplontic: the adult structures are always haploid (n). Only the zygote is 2n.

Source:

Mader, Sylvia S. Inquiry into Life, 9th ed. Toronto: McGraw-Hill, 2000.

thefreedictionary.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Biology: difference between mitosis and meiosis

The tutor visits the related terms mitosis and meiosis.

Mitosis is, from a simple point of view, cell division: it forms two daughter cells, each identical to the original parent cell. It is the process by which organisms grow and heal. The daughter cells, like the parent from which they emerged, have the full number of chromosomes: 2n.

Meiosis is quite different from mitosis, and perhaps more complex to imagine. Meiosis is not used to grow or repair structures; rather, it’s used for reproductive purposes. In humans, meiosis only occurs in the testes (to produce sperm) and in the ovaries (to produce eggs). In plants, meiosis occurs in the sporophyte(s). Higher plants have two types of sporophytes: for example, flowering plants have ovules and pollen sacs. Lower plants or fungi may have only one type of sporophyte.

Meiosis produces reproductive cells that have half the chromosomes present at the beginning of the process. Cells produced from meiosis are referred to as having n chromosomes, rather than 2n.

Source:

Mader, Sylvia S. Inquiry into Life, 9th ed. Toronto: McGraw-Hill, 2000.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Weather and Seasons: first day of spring, 2016, Campbell River

The tutor shares reflections about, from his point of view, the first day of spring, 2016, in Campbell River.

As many of my readers realize, I’m a Maritimer. The mild weather on Canada’s west coast continues to impress me, even after nearly 30 years living here.

As I mentioned in last year’s post about the first day of spring here, March 21 doesn’t aptly target it. The true change in warmth and sunshine is usually apparent much earlier. My definition for the first day of spring: It’s the first sunny day (in the new year) with high temp 10°C or above. By that definition, the first day of spring, 2016, in Campbell River, is today, January 28. Environment Canada reports the temp at 11°C, with sunny conditions. I’ve been outside; it’s true.

I’ve noticed a couple of signs of spring. Last week, downtown, daffodil shoots were a few inches up from the soil. This morning, as I opened the gate, a fly buzzed about in the sun. However, I wouldn’t have guessed that today would mark the change. Amid exams and other activities, this occasion is a very pleasant surprise.

I’ll be further discussing the evolving spring season in future posts:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Biology: insulin response and insulin resistance

The tutor defines insulin response and insulin resistance and explains their connection.

Recall: herein, ACV means apple cider vinegar.

In yesterday’s post I mentioned my discovery that apple cider vinegar potentially increases the effectiveness of insulin.

As carbohydrates are digested, glucose (a type of sugar) enters the blood from the digestive system. The body’s response to the rising blood sugar is to release insulin. It’s known as the insulin response. Insulin enables glucose to enter cells so they can use it for energy or fat storage.

Sometimes, body cells may become less sensitive to insulin, which is known as insulin resistance. Then, the insulin is less effective at conducting glucose from the blood into the cells; more insulin is needed to do the same as before.

Therefore, if insulin resistance increases, so must the insulin response. The fact that ACV seems to increase insulin’s effectiveness leads to the consequence that it apparently lowers the body’s insulin response.

I’ll be discussing related ideas in coming posts:)

Source:

authoritynutrition.com

spinalhealth.net

medicinenet.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: diet and weight loss: apple cider vinegar

The tutor seeks the truth about a celebrated health food, apple cider vinegar.

Herein, ACV means apple cider vinegar.

Fifteen years ago, I overheard my boxing coach recommend ACV to a fighter who was struggling to make weight. Since then, I’ve noticed the promotion of ACV from diverse sources. Casually I’ve wondered: Is it really as beneficial as suggested? Today, I decided to begin research towards finding out.

ACV, it seems, could very well offer at least two health benefits. Most importantly, it apparently increases the effectiveness of insulin, depressing blood sugar after a carbohydrate-rich meal.

Secondly, ACV may hinder digestion of carbohydrates, so less calories are absorbed from a meal. In nature, passing up calories would not be advantageous; however, in a culture that’s generally overweight, it seems to be.

The two benefits mentioned above, to be done justice, need to be followed up with further posts. I’m intrigued with what I’ve discovered so far.

HTH:)

Source:

authoritynutrition.com

drwhitaker.com

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Chemistry: why equilibrium persists

The tutor explains why a chemical system will exist at equilibrium.

Over my last couple of posts I’ve defined reaction and equilibrium. I’ve also explained why a reaction will proceed spontaneously. (For background see here and here.)

Today, the focus is equilibrium: why a given chemical system may not decisively transform in one direction, but instead persist in two complementary forms. Consider, by example, the following equilibrium:

    \[3H_2+N_2 \rightleftharpoons 2NH_3,\ \  \Delta H=-92kJ/mol\]

Recall, from my previous post, Nature’s two preferred trends:

  1. Entropy increasing.
  2. Enthalpy decreasing.

High entropy favours the left side of the equilibrium above, since it has 4 molecules, as opposed to only 2 on the right. However, low enthalpy favours the right side, denoted by negative \Delta H.

With one of Nature’s trends driving to the left, while the other is driving to the right, the system remains undecided; the molecules constantly break down and reform from side to side. Left alone, a stable proportion of each will persist, while the individual molecules constantly change between forms. Such is an equilibrium.

Source:

Hebden, James A. Chemistry: Theory and Problems, book 2. Toronto: McGraw-Hill
   Ryerson, 1980.

Mortimer, Charles E. Chemistry, 6th ed. Belmont: Wadsworth, 1986.

Thanks to quicklatex and omega.albany.edu

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Chemistry: why a reaction proceeds from left to right

The tutor explains why a reaction goes forward.

Consider, from my previous post, the following reaction:

C3H8 + 5O2→3CO2+4H20,   ΔH=-2219 kJ/mol

This reaction proceeds from left to right because, by so doing, it follows nature’s two preferred trends:

  1. Entropy rises (for a definition of entropy, see my post here).
  2. Enthalpy falls (for a definition of enthalpy, see my post here).

At a glance, the rise in entropy can be noticed by the increase in molecules from left to right (6 to 7). The fall in enthalpy is indicated by the negative ΔH value.

A chemical transformation that produces, simultaneously, a rise in entropy and a fall in enthalpy, will be spontaneous: once started, it will self-sustain.

Source:

docbrown.info

Mortimer, Charles E. Chemistry, 6th ed. Belmont: Wadsworth, 1986.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Chemistry: difference between reaction and equilibrium

The tutor explains the distinction between reaction and equilibrium.

A reaction is stated as

reactants→products

An example:

C3H8 + 5O2→3CO2+4H2O

A reaction is thought to proceed until at least one of the left side ingredients is gone.

An equilibrium is stated as

    \[reactants \rightleftharpoons products\]

An example:

    \[3H_2 + N_2 \rightleftharpoons 2NH_3\]

The \rightleftharpoons symbol denotes equilibrium, and suggests that the process works both ways: the molecules on the right side can act in reverse and become the ones on the left. Because some molecules are transforming from left to right, while others are transforming in the reverse direction, the system, after some time passes, arrives at a steady state with a constant proportion of molecules either side. The specific proportion depends on temperature.

Why some chemical transformations are reactions, while others form equilibrium, I’ll explain in a coming post:)

Source:

Mortimer, Charles E. Chemistry, 6th ed. Belmont: Wadsworth, 1986.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: the Hydro bill

The tutor investigates higher household usage over last year.

For Nov11-Jan11, our daily household usage this year was 6kWh above last year. My wife points to the new electric fireplace downstairs as the culprit. More specifically, she means that it’s been left on while people weren’t in the room. (The people who left it on would be the culprits.)

To be sure, late December through early January was cold: the first week back to school, snow still lay around from December 23. Around here, cold temperatures sustaining that long are rare.

The heat from the electric fireplace was needed anyway. The fan, however, doesn’t produce heat, but just circulates it. I’ve looked around and suspect, from hearth.com, that the fan might use 120W (0.12kW). Left on 14 hours per day, it would use 0.12kWx14h=1.68kWh. That’s more than 25% of the 6kWh per day over what we used last year.

Where the other three quarters went, I’ll continue to investigate:)

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.