Amaris's Biology: October 2011

Monday, October 31, 2011

2.68b Osmoregulation

Osmoregulation : osmosis + control

By controlling the salt and water in the blood the Kidney can keep the blood isotonic (optimum) with the cells cytoplasm, therefore maintaining function of the cells.

2.68a Excretion

The kidney (and liver) and the excretion of Urea (carries potentially toxic hydrogen)

(the filtered blood - free of urea - travels back)

2.67b Human Organs of Excretion

1. Lung
- carbon dioxide (from respiration)

2. Kidney
- Water
- Urea (amino acids)
- Salts

3. Skin
- Through sweat : water, salts
- Small amount of Urea

1. Photosynthesis

carbon dioxide + water ---> glucose + oxygen

- oxygen is a waste molecule and therefore excreted

2. Respiration

glucose + oxygen ---> ATP + carbon dioxide + water

- Carbon dioxide in a waste molecule and therefore excreted

Sunday, October 9, 2011

3.34 Causes of Mutation

1. Radiation e.g x-rays

sunshine (UV Rays ) > skin cancer

2. Chemicals e.g Tars (tobacco) > cancer

Chemicals which cause mutations are called, Mutages.

Chemicals that cause cancer are called Carcinogens.

3.33 Antibiotic Resistance

As the resistant from increasingly survives over time, it becomes more common

Meaning the antibiotic no longer works

3.2 Types of Mutation

3.31 Evolution

Evolution : change in the form of organisms (new forms)
: change in the frequency (number) of alleles
: increase in the frequency of the alleles for resistance

Natural Selection : Mechanism of evolution

3.30 Mutation

The change (mutation) creates a new version of the allele

Can affect: phenotype, production of protein

Mutation, changes base sequence

3.29 Species Variation

Variation = see-able differences in phenotype

Individual Phenotype = Genotype + Environment
Vpop = Vgeno + Venvironment

1. Vpop = Vgeno (no environmental impact)
   e.g bloodgroup

2. Vpop = Vgeno + Vpop
   e.g height

3. Vpop = Venvironment (no genotypic influence)
   e.g home language