Homologous pairs of chromosomes are approximately the same length and thier centromere is at the same position. One is from the father and the other is from the mother. While their genes are in the same order, they have different alleles that code for different things. For example one of the chromosomes might code for brown hair, while the other might code for blond hair.
A homologous pair of chromosomes is a pair of chromosomes that contain the same genes, but different alleles of the same genes. One of the chromosomes is maternal and the other is paternal. During Meiosis only one of the chromosomes from each homologous pair goes into a daughter cell, creating 4 daughter cells, which are haploid.
I would not worry about homologous pairs of chromosomes, as they came up in june 2012, so its very unlikely for it to come up in jan 2013.
And thank you too! Yes it quite unlikely Good luck for next week !
I've revised upto section 1.2.2 Transport in animals. I Have half of this left and the whole of 1.2.3 Transport in plants. Ive hardly done any past papers. Advice? what should i be doing right now
I've revised upto section 1.2.2 Transport in animals. I Have half of this left and the whole of 1.2.3 Transport in plants. Ive hardly done any past papers. Advice? what should i be doing right now
Finish your revision?
You still have 8 days left, you've got enough time to get a decent understanding of the specification. If you work hard tomorrow, you could finish Transport in animals and plants and then you could tackle some past papers, and see what mark you are getting.
I really need some advice. I constantly reread notes and material but as soon as I get into exams I go blank. What are some of your techniques on exam days? I was thinking about waking up reeeeally early like 5am on the day and going through everything before hand, bad idea?
I really need some advice. I constantly reread notes and material but as soon as I get into exams I go blank. What are some of your techniques on exam days? I was thinking about waking up reeeeally early like 5am on the day and going through everything before hand, bad idea?
I think the latter is a really really bad idea, the best thing is to be relaxed, which means get a good night sleep. Eat a good breakfast at the table don't rush. And overall be confident in the exam, this can only happen by revising and taking in the content. If you do that you should be fine. Also practice past papers a lot. Not just once, I've done every past paper at least once. You will soon see the progress.
Hi-actually what topics came up on OCR AS unit 2 in the summer that guys are taking on January 15th? My school has had no mocks, so don't have the questions to look at again. Thanks.
Pretty simple question I think. But can anyone tell me what are sieve tube elements for? Thanks
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Phloem tissue transports solute (translocation). The tissue is comprised of two types of cells, sieve tube elements and companion cells. The sieve tube elements have no Nucleus or Ribosomes and very few mitochondria, forming a tube to allow the movement of solutes to take place. However, translocation is an active process which requires energy so the companion cells provides energy and nutrients which diffuse into the sieve tube elements through the Plasmodesmata.
I don't get this question and the units In regards with converting
You would use the equation Actual Size = Image Size / Magnification
The magnification in the question is given as x25000. The image size is 3mm, which is 3 x 106 nm (3000000 nm). Put this into the equation: Actual Size = (3 x 106)/25000; Which gives you 120nm