#bio101

[yellowgnomeboots]

I’m going to try working through this Bio101 course on the Saylor Academy site

https://learn.saylor.org/course/view.php?id=349

but I’m already a bit nervous because I never understood “studying” - I just read things and do things and remember some of them and forget others. The deliberate part of learning and remembering I don’t understand at all.

[thelyd]

studyblr community I know you still exist, I’m floundering with Biology 101. “basic” stuff like four types of protein structure, chemical bonds, etc....I’m just super frustrated right now and kinda frozen in place cuz i’m so overwhelmed. Any tips or advice for frustration or study resources? Thnx ;-;//

[geocean-man]

Cell Transport

Explore the types of passive and active cell transport with the Amoeba Sisters! This video has a handout here: http://www.amoebasisters.com/handouts.html Exp...

The Amoeba Sisters talk about cell transport in this animated video 

[llaethmel-blog]

Anyone currently taking a hybrid bio course in college?  Any tips on time management?

[sciencesoup]

For all those who are currently suffering through CRUNCH TIME of final exams, I want to remind you that I have a series of Bio101 articles where I explain the main concepts of last year high school / first year university biology, from mitosis and cell division to introductory genetics to the good ol’ ETC! 

Go check it out for some (hopefully) straightforward explanations and some (definitely) fabulous diagrams, hand-drawn by me.

[sciencesoup]

I saw the ask about the tonicity post, followed the link... Great job on it btw. I was just wondering if you knew of a good way to explain osmolarity and its relation to tonicity? my teacher droned on about it and I just got really confused.

This Khan Academy video may help. 

A quick overview from me: both terms describe the concentration of solute on either side of a membrane, but tonicity only describes what happens to the solutes that can't penetrate the membrane. I.e., a cell's tonicity is how the concentration of impermeant solute drives the movement of water in or out of the cell. 

On the other hand, osmolarity considers the total concentration of solutes: not just the impermeant ones, but the permeant solutes too (which can pass through the cell's membrane). So, you have to consider the fact that permeant solutes and water will move through the cell's membrane before it reaches equilibrium with its surroundings.

[number1tutors-blog]

Bio101 Bio 101 Week 2 Powerpoint DNA PROFILING TECHNOLOGY Axia 2014 Axia Uop Class

Bio101 Bio 101 Week 2 Powerpoint DNA PROFILING TECHNOLOGY Axia 2014 Axia Uop Class

[sciencesoup]

Probability in Genetics

So far we’ve been talking about simple ratios, but how can we mathematically figure out the probability or the percentage that an organism will inherit a trait?

Consider a cross between YyRr and YyRr. Using a Punnett square, we can deduce that for colour, ½ the offspring will be Yy, ¼ yy, and ¼ YY. The same probabilites apply for shape: ½ Rr, ¼ rr, and ¼ RR. (Remember Y=yellow, y=green, R=round, r=wrinkled.) But how do we then figure out how many will be round and yellow, or green and wrinkled?

The rules of probability, of course.

We can determine the probabilities of the genotypes by just multiplying the traits we want to know about together. For example, what’s the probability of the pea ending up yellow and wrinkled? Well, we know that ¾ of our offspring will be yellow, and ¼ will be wrinkled. ¾ x ¼ = 0.1875. So about 18.75% of our offspring will be both yellow and wrinkled. (If you don’t like fractions, just use 0.75x0.25.)

What about green and wrinkled? ¼ x ¼ = 0.0625. So 6.25% will be green and wrinkled. We can do the same for the others:

Yellow and round: ¾ x ¾ = 0.5625 = 56.25%

Green and round: ¼ x ¾ = 0.1275 = 18.75%

Adding all of these up gets you 100%, of course. It also gives us our ratio that we’ve talked about—9:3:3:1.

Further resources: Probability in Genetics: Multiplication and Addition Rules video