GCSE Biology Revision Paper 1 Flashcards

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Questions and Answers

Suggest one possible cause of the anomalous result.

measurement error

What are two reasons how lungs are adapted for gas exchange?

large capillary network and good supply of blood

Name the process by which water molecules enter the root hair cell.

osmosis

Explain how plants absorb nitrate ions from soil.

Active transport (because) energy is needed (to move nitrate ions) from a lower concentration (in the soil) to a higher concentration (in the root / cell). Signup and view all the answers

Describe what happens during each stage of the cell cycle.

Stage 1 - DNA replicates and the subcellular structures increase in number; Stage 2 - One set of chromosomes is pulled or moved to each side; Stage 3 - Cytoplasm and cell divide to form 2 cells. Signup and view all the answers

Why does each different type of lipase act on only one specific type of lipid molecule?

Each active site has a specific shape (so it only fits one type of lipid molecule). Signup and view all the answers

Describe how the students would find out if the liquid from the leaf contained glucose.

Add Benedict's solution to the liquid, boil or heat. If glucose is present, the blue color changes to yellow / green / orange / brown / (brick) red. Signup and view all the answers

Explain why the leaf in the light for four days contained both glucose and starch.

Glucose from photosynthesis (excess) glucose converted to starch. Signup and view all the answers

Explain why the leaf left in a cupboard with no light for two days contained glucose but did not contain starch.

Starch (stores) have been converted to glucose. Glucose is used for respiration. There is no light to make (new / more) glucose by photosynthesis. Signup and view all the answers

How do thorns defend the gorse plant?

To deter herbivores and to prevent animals from damaging it. Signup and view all the answers

A scientist noticed that in one area the gorse plants had yellow leaves and had stunted growth. Explain two other possible reasons for the yellow leaves and stunted growth.

Lack of magnesium (ions) so not enough chlorophyll for photosynthesis; Infected by aphids that remove sugars from phloem leading to insufficient glucose for growth. Signup and view all the answers

Suggest how the nodules benefit the bacteria.

(Bacteria) contain glucose (from the plant) (glucose used) for respiration. Signup and view all the answers

Explain how the nodules benefit the gorse plant.

(Gorse plant) obtains nitrate (ions) needed for amino acids / proteins. Signup and view all the answers

Which plant material was chewed as a painkiller?

Willow bark Signup and view all the answers

Suggest two other factors which the scientists would have controlled in their analysis.

Diet and fitness level. Signup and view all the answers

Give two other conclusions about the relative risk of developing cirrhosis of the liver related to alcohol consumption.

Consuming alcohol increases the relative risk (with / without meals); Even (small amounts of alcohol at) 25 g/week increases the RR if not with meals. Signup and view all the answers

Suggest two reasons why the data is considered to be valid.

Well controlled; Large number in survey. Signup and view all the answers

Suggest one aspect of the survey which might reduce validity.

People lie about alcohol consumption. Signup and view all the answers

Describe the effects of liver failure on the human body.

No bile made (in the liver); Fats/lipids are not emulsified; pH of small intestine will not be alkaline/neutralized; Food not digested/absorbed so may lose weight; Lactic acid not broken down/oxidized; Liver does not break down/remove other toxins; Cannot control blood glucose and can even cause diabetes. Signup and view all the answers

Explain how increased phagocytosis of the Candida albicans pathogen will help the patient.

More Candida albicans pathogens will be engulfed in white blood cells, therefore less damage to cells. Signup and view all the answers

Describe how the clinical trials should be carried out.

Given first to healthy volunteers at (very) low dose to test it is safe or to test for toxicity or to check for any side effects; then to some patients (with the disease) or people with the disease to test for the correct/optimum dose, to check for any side effects, and to test for efficacy; long duration. Signup and view all the answers

Study Notes

Causes and Errors

Anomalous results can occur due to measurement errors.

Gas Exchange in Lungs

Lungs have a large capillary network to maximize gas exchange.
There is a good supply of blood to facilitate efficient transport of gases.

Water Uptake in Plants

Water molecules enter root hair cells by osmosis.

Absorption of Nitrate Ions

Nitrate ions are absorbed through active transport, requiring energy to move ions against a concentration gradient.

Cell Cycle Stages

Stage 1: DNA replicates; subcellular structures increase.
Stage 2: Chromosomes are separated to opposite sides.
Stage 3: Cytoplasm and cell divide to produce two daughter cells.

Lipase Specificity

Each type of lipase has a specific active site shape, allowing it to interact with only one lipid type.

Testing for Glucose

To test leaf liquid for glucose, add Benedict's solution and heat. A color change from blue to yellow/green/orange/brown indicates glucose presence.

Photosynthesis Products

Leaves exposed to light for four days contain both glucose and starch due to photosynthesis; excess glucose is converted to starch.

Dark Conditions Effect

Leaves in darkness for two days have glucose but no starch as stored starch is converted back to glucose for respiration, with no new glucose production from photosynthesis.

Plant Defense Mechanisms

Thorns on gorse plants deter herbivores and prevent damage from animals.

Causes of Plant Deficiencies

Yellow leaves and stunted growth may result from:
- Lack of magnesium, leading to insufficient chlorophyll and reduced photosynthesis.
- Aphid infestation, which siphons sugars from phloem, limiting glucose for growth.

Bacterial Nodules

Nodules provide bacteria with glucose from the plant for respiration.
Gorse plants receive nitrate ions from nodules, essential for amino acid and protein synthesis.

Medicinal Plant Material

Willow bark has been historically chewed as a painkiller.

Controlled Factors in Studies

Controlled factors in health analyses include age, gender, diet, and fitness level.

Alcohol Consumption Risks

Alcohol increases the relative risk of cirrhosis; small amounts can elevate risk even when not consumed with meals.

Validity of Data

Data validity is supported by controlled conditions and a large sample size.
Potential validity issues include respondents misreporting alcohol consumption.

Consequences of Liver Failure

Liver failure leads to:
- No bile production, affecting fat emulsification.
- Altered pH in the small intestine.
- Inability to digest and absorb food, resulting in weight loss.
- Accumulation of lactic acid and toxins.
- Impaired blood glucose control, potentially causing diabetes.

Phagocytosis Benefits

Increased phagocytosis of Candida albicans reduces cellular damage by engulfing more pathogens.

Clinical Trial Protocols

Initial trials on healthy volunteers at low doses assess safety and side effects.
Subsequent trials involve patients to determine the optimal dosage and efficacy over an extended period.

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Description

These flashcards are designed to help GCSE Biology students revise key concepts covered in Paper 1. Topics include gas exchange in lungs, osmosis, and nutrient absorption in plants, providing a thorough review of essential biological processes. Use these cards to test your knowledge and enhance your understanding of the material.