2011 Trial Biology Paper 123

Dear my students,

Below are some of the biology trial papers which we did not have time to discuss in class, i hope you could find time to practise them before your final spm.

1) sbp - paper 123

2) mrsm - paper1, paper2, paper3 or all paper 123
- p1 answer,

3) kedah - paper 123

4) perak - p2Q, p2Answer, p3Q, p3Answer

5) kelantan - p1, p2Q&A, p3Q ,p3Q&A,

6) terengganu - p3 Q, p3 Answer

7) melaka - p2Q&A

8) pahang - p123Q&A

9) johor - p2Q, p2Answer, p3Q, p3Answer

10) negeri sembilan - p2Q, p2Answer

11) sabah

12) sarawak

The original papers can be found on http://www.edu.joshuatly.com/, http://www.bumigemilang.com/, http://www.banksoalanspm.com/, http://www.myschoolchildren.com/.


I wish all of you the very best in your spm examination & in your future undertakings.

take care

rgds,
sharon

What's after SPM - a good read

Hi all,.......Perhaps after your spm ended this december, go get this book....& read it.

".......101 young Malaysians were united by a call to reveal and describe defining moments in their lives after SPM. As young Malaysians, we all worry about not getting scholarships or being accepted into our desired universities. Many wonder and agonize over which course suits them best."

click here - about Project What's After SPM

click here - for book review.

What’s After SPM is now available at MPH, Kinokuniya and Borders nationwide! The ISBN is 9789834485412 at rm19.90.


all the best!

sharon

An introduction :How to choose quadrat size and shape?

Dear students,

To learn more about population ecology, herewith the link you can learn more on what quadrat size (10cm x 10cm, 0.5m x 0.5m, 1m x 1m, 10m x 10m?) and what quadrat shape (square, circle or rectangle?) to use. Hopes these are helpful.

CLICK HERE to go to link 1

CLICK HERE to go to link 2

all the best

rgds

sharon

Can you choose your child's gender? Yes, you can, but would you do this?

click here for my older post on gender selection.

US Siamese Twins - Kendra & Maliyah Herrin

1) this is a miracle!


• Kendra & Maliyah were born on 26 Feb 2002
• Separated on August 2006
• The girls had been born fused at the midsection, sharing a kidney, a liver, a pelvis, one set of legs and part of their intestines.
• Doctors successfully completed 26 hours of separation and reconstruction surgery.
• They were 4 year-old when separated.
  
• Watch their updates at YouTube :http://www.youtube.com/watch?v=rwyrensj-gI

2) Abby & Brittany Hensel - another conjoined twins (NOT separated)

3) The first Siamese Twins - Chang & Eng

Dolphins slaughtering in Taiji, Japan

I have just watched this documentary 'The Cove'. An exciting film, with powerful message!

It is sad to know that while we are enjoying ourselves watching dolphin shows, the dolphins are suffering, they are not smiling!!. Many die during this captivity. When they can't bear the pain, they can actually commit suicide by stop breathing!

See for yourselves how this intelligent creatures are slaughtered every year in Japan from Sept to Mar. As many as 20,000 dolphins are killed, for meat. Worst still, research shows dolphins meat are highly contaminated with mercury, upto 2ooo ppm (safe level is 0.5ppm).

Dolphin meat is sold as other meat such as 'whale' meat to consumers worldwide, are you consuming dolphin meat at the japanese restaurant? you don't even know. So, pregnant women & children, stay away from the meat!

Stop the killing of dolphins!

you can get the dvd at speedy video at rm16.90, or just download from takepart at The Cove.

read more at this link: The Cove - dolphins slaughter

Spermatogenesis & Oogenesis

Here are some useful diagrams to help you recall spermatogenesis, Oogenesis & the menstrual cycle.


1) Spermatogenesis

• occurs in the testes of the male body at puberty.
• sperms/spermatozoa can survive in the human female body for about 72 hours (3 days).
• the smallest cell in the male body & it can swims by beating its tail.
• formation of healthy sperms require 2-3 oC lower than ideal body temperature.
• each spermatogonium will give rise to 4 genetically different funtional sperms.
  

2) Oogenesis
a)

• Oogenesis is the production of ovum which occurs in the ovary of the female.
• One oogonium will eventually produce one functional ovum/secondary oocyte & polar bodies (which hv no function in fertilisation)
• Ovum/secondary oocyte is the biggest cell in the female body, about 0.02cm in size.
• it couldn't move by itself & can survive for about 24 hours (one day)
• after that, the ovum/secondary occyte is considered too old to be fertilised to produce a healthy embryo.

b) refer to your notes for comparison between oogeneis & spematogenesis.

• In oogenesis, the cell division is interrupted at Prophase I and Metaphase II.

3) The menstrual cycle

• ovulation (the release of secondary oocyte from the ovary) occurs at around day 14.
• 2 groups of hormone that regulate the menstrual cycle are:
  i) pituitary hormone - FSH & LH
  ii) ovarian hormone - oestrogen & progesterone.

About forest farming

here are some info. on forest farming for your reading.

Introduction:
Forest farming practices can be used by private enterprise to grow desirable non-timber forest products on private lands, to supplement family income, and to allow biodiversity to reestablish within forests.

Definition:
Special forest products (SFPs) or non-timber forest products (NTFPs) are high-value specialty product items derived from green plants, fungi, invertebrates, and other organisms that inhabit forested areas.

These products fall into four general categories

1. food (e.g., mushrooms and nuts)
2. botanicals (e.g., herbs and medicinals - tongkat ali, ginseng, kacip fatimah)
3. decoratives (e.g., floral greenery and dyes)
4. handicrafts (e.g., baskets and wood products -rattan)

Concepts & Principles:

In forest farming practices, high-value specialty crops are intentionally cultivated under the protection of a forest overstory that has been modified and managed to provide the appropriate microclimate conditions.

Typically, these systems are established on private land by thinning an existing forest or woodlot to leave the best crop trees for continued wood production and to create the appropriate conditions for the understory crop to be grown.

Then, the understory crop is established and intensively managed to provide short-term income.

Planning & Design:

A forest farming practice is usually a small area of land (5 acres or less) whose vertical, horizontal, and below-ground dimensions are managed intensely to produce multiple crops simultaneously.

Systems usually focus on a single SFP plus timber, but can include several products.

Examples of systems include:

1. ginseng + maple syrup + bee products + timber
2. shiitake mushrooms + timber
3. ferns + beargrass + mushrooms + timber
4. ginseng + walnuts + black walnut veneer logs

The amount of light in the stands is altered by thinning, pruning, or adding trees.
Existing stands of trees can be intercropped with annual, perennial, or woody plants. Compatibility among understory and overstory plants and cultural methods is essential.

Benefits:

1. Economic
   Some products especially medicinals and botanicals can have tremendous economic value, while others provide a lower but steady supplemental income.
   
2. Conservation and System-Level
   Forest farming activities modify the forest ecosystem but do not significantly interfere with its crucial contributions of water capture and filtering, soil erosion control, microclimate moderation, and wildlife habitat.
   Producers should avoid harmful species and follow EPA approved guidelines for herbicides, fungicides, and insecticides.
   
3. Social
   Forest farming provides opportunities to generate short-term income from existing woodlots,with minimum capital investment. Especially on small family farms, this can contribute significantly to rural economic development and diversification.

source: forest farming - An Agroforestry Practice .

Mitosis and Meiosis

Image shows karyotype of a female. Her somatic cell has a diploid number of 46.

refer to your chapter 5 note.
What is diploid number & haploid number of chromosome?
1. Diploid - organisms or cells that have 2 sets of chromosomes.
2. Haploid - cells that have only one set of chromosomes.

Here are some images which are related to cell division:

1. Image below shows the chromosomes, DNA, histone proteins inside the nucleus of a typical cell.

2. Image below shows chromosomes.

• When the chromosome condense, coil-up and tighten during prophase of mitosis (or prophase I or prohase II of meiosis), the chromosome appear as two identical chromatids called sister chromatids attached together at the contromere.
  
  

3. Prophase I of meiosis I.

• At the chiasma, exchange of genetic material between the non-sister chromatids of bivalent through the process of crossing over.
• Crossing over results in new combination of genetic material and is important source of genetic variation.
  

4. the differences between Meiosis & Mitosis

Plant Hormone

what is coleoptile? it is a tough protective sheath that encloses/protects the tip of a shoot.

• refer to page 22-24, chapter 3.
  
• Plant hormone is a chemical substance produced by plant, which is able to influence the growth & development of the plant.
  
• Plant hormones can be used to produce fruit without seeds, to ripen fruits, to increase the size of fruit, in growing cuttings, controlling weeds, etc.
  
• There are 5 classes of plant hormone:
  1. Auxins (Indole Acetic Acid) - promotes cell elongation at stem tip, roots initiation, fruit development.
  2. Cytokinins - promotes cell division
  3. Gibberellins - promotes cell elongation
  4. Abscisic acid - promotes seed dormancy
  5. Ethylene (ethene) - a gas hormone which is used to ripen fruits, etc
  
• Auxin is a plant hormone that controls tropic response.
• It is produced in the apical meristem of the shoot & root.
• Auxin diffuse from zone of cell division into zone of cell elongation where it stimulates the cell to elongate.
  
• Diagram below shows:
  1. concentration of auxins needed for maximum growth of shoots will inhibit roots growth.
  2. at low concentration of auxin hormone, this promotes roots growth but cannot stimulate shoots growth.
  
  

Below are some experiments related to Auxins hormone:

1. The coleoptile tip is removed (just above the zone of cell elongation). Gelatin/agar block which contains auxin hormone is then placed at one side of the coleoptile.
Results: coleoptile bending towards the side without the agar block.

2. Role of auxins in controlling phototropism: (unilateral light)

3. Shoot placed horizontally. Auxin hormone will accumulate at the lower side.

4. Diagram below showing geotropism on shoot & root of seedling when the seedlings are placed in different positions. The shoot shows negative geotropism while the root shows positive geotropism.