Biology big markers

What is the Human Impact on Peat Bogs?

• Peat forms from partially decomposed plant material.

• Peat stores carbon.

• Peat is removed for fuel or compost.

• Carbon dioxide is released when peat is burned.

• More greenhouse gases enter the atmosphere.

• Global warming may increase.

• Habitats are destroyed.

• Biodiversity decreases.

Carbon Cycle

• Dead leaves decay or decompose.

• Microorganisms (decomposers) break down the dead material.

• The microorganisms respire.

• Respiration releases carbon dioxide into the atmosphere.

• Plants take in carbon dioxide during photosynthesis.

• The carbon is used to make new plant biomass (growth).

DMRCCP

(Diya Marries Ryan, Cold Palmer Parmar)

Decompose or decay (leaves/organisms)

Microorganism breaks down the dead material

Respires (the microorganisms)

Carbon dioxide is released as a result

Photosyntheisis takes in the CO2

Produces new plant

Describe the process of the Water Cycle

• Water evaporates from rivers, lakes and seas (evaporation)

• Water vapour cools and forms clouds (condensation)

• Water falls from clouds as rain, snow, sleet or hail (precipitation)

• Water flows over the land into rivers and lakes (surface runoff/drainage)

• Water is released from plants into the atmosphere (transpiration)

ECCPDT

Every Cool Pool, Drains Today

Evaporation od water from rivers, lakes and seas

Codensation when water vapour cools and forms clouds

Precipitation when water falls down clouds

Drainage and runoff when water flows over the land into rivers and lakes

Transipration when water is released from plants to the atmosphere

Explain how two hormones keep the blood glucose concentration within the normal range.

insulin is secreted by the pancreas causing glucose to enter cells

glucose is converted to glycogen in the liver / muscle cells for storage

this causes blood glucose concentration to return to normal so insulin secretion slows / stops / decreases

when blood glucose concentration is low glucagon is secreted by the pancreas

which causes breakdown of glycogen in the liver into glucose

this causes blood glucose concentration to return to normal so glucagon secretion slows / stops / decreases

India Got No Good Batesman Now

• I = Insulin is secreted

• G = Glucose enters cells, where it is converted to glycogen

• N = blood glucose returns to Normal (insulin decreases)

• G = Glucagon is secreted

• B = glycogen is Broken down into glucose

• N = blood glucose returns to Normal (glucagon decreases)

Steps in IVF

Inject FSH and LH into women

collection of (mature) egg(s) from the ovary

(which are) fertilised (in the laboratory)

develop into embryo(s) (in the laboratory)

embryo(s) inserted into uterus / womb

Difference of Meiosis and Mitosis

four genetically different cells formed from meiosis and two genetically identical cells formed from mitosis

One cell division in Mitosis but 2 in Meiosis

Mitosis in diploid whereas Meiosis is haploid

Explain how HGP could be important for people in the future

dentify genes linked to (certain) disease so can lead to better prevention / treatment of that disease or identify genes causing inherited disorders (1)

so may prevent children being born with the disorder by using IVF or gene therapy (1)

or tracing human migration patterns from the past or evolution of humans (1)

so to better understand the ancient history of humans (1)

Describe how carbon from the atmosphere is cycled through living organisms

Photosynthesis

• (carbon dioxide is) taken in through stomata / leaves

• (carbon dioxide is) used in photosynthesis

• to make glucose / carbohydrate

• (glucose used) to make other carbon compounds or named example such as proteins, lipids

• (glucose) stored as starch

Feeding

• plants are eaten / consumed by animals

• which use the carbon compounds to make other carbon compounds

Decay

• when plants / animals die they are decomposed / decayed

• by microorganisms

• which use the carbon compounds to make other carbon compounds

Respiration

• plants / animals / microorganisms respire

• (respiration) releases carbon dioxide back into the atmosphere

Describe the type of cell division that produces gametes

(called) meiosis

• DNA / chromosomes replicate or DNA makes a copy

• two divisions to form 4 cells

• so only 1 set of chromosomes per cell

• (daughter cells / gametes) are all genetically different

Selective breeding process

• Select plants with the desired characteristics.

• Cross-breed them.

• Select the offspring showing the desired characteristics.

• Repeat the process over many generations until all offspring show the characteristic.

How could antibiotic resistance happen?

• Random mutations occur in bacteria.

• Some mutations make bacteria resistant to an antibiotic.

• Antibiotics kill non-resistant bacteria.

• Resistant bacteria survive.

• Resistant bacteria reproduce.

• They pass the resistance allele to offspring.

• The proportion of resistant bacteria increases.

• Eventually, most of the population becomes resistant.

Describe the Natural Selection and Evolution

• Variation exists within a population.

• Some individuals have advantageous characteristics.

• These individuals are more likely to survive.

• They are more likely to reproduce.

• They pass advantageous alleles to offspring.

• The frequency of these alleles increases.

• More individuals inherit the advantageous characteristic.

• The population becomes better adapted over time.

How can we be Maintain Biodiversity?

• Breeding programmes for endangered species.

• Protecting and restoring habitats.

• Reintroducing field margins and hedgerows.

• Reducing deforestation.

• Recycling resources rather than landfill.

• Reducing greenhouse gas emissions.

• Conservation programmes increase species numbers.

• Biodiversity is maintained for future generations.

What are the effects of Deforestation

• Trees are removed.

• Less photosynthesis occurs.

• Less carbon dioxide is removed from the atmosphere.

• More carbon dioxide remains in the atmosphere.

• Burning trees releases carbon dioxide.

• Habitats are destroyed.

• Biodiversity decreases.

• Climate change may be accelerated.

How is Genetic Engineering perfomed?

• Desired gene is identified.

• The gene is cut out using enzymes.

• A vector (such as a plasmid) is used.

• The gene is inserted into the vector.

• The vector transfers the gene into another organism.

• The organism now contains the desired gene.

• The gene is expressed.

• The desired characteristic is produced.

Explain how a population of bacteria becomes resistant to an antibiotic

• Random mutations occur in some bacteria.

• A mutation may make a bacterium resistant to an antibiotic.

• When the antibiotic is used, non-resistant bacteria are killed.

• Resistant bacteria survive.

• The surviving resistant bacteria reproduce rapidly by binary fission.

• They pass the resistance gene to their offspring.

• The proportion of resistant bacteria in the population increases.

• Eventually, most or all of the bacterial population becomes resistant to the antibiotic.

Explain why sexual reproduction produces genetic variation

• Two parents are involved.

• Meiosis produces genetically different gametes.

• Gametes contain half the chromosomes.

• Fertilisation combines genetic information from both parents.

• Offspring inherit different alleles from each parent.

• This creates genetic variation in the offspring.

Evaluate the fossil record as evidence for evolution

• Fossils show that organisms in the past were different from those alive today.

• The fossil record shows gradual changes in organisms over time.

• Some fossils are transitional forms, linking older and newer species.

• However, many organisms did not fossilise.

• Some fossils have been destroyed by geological activity.

• Therefore, the fossil record provides strong evidence for evolution, but it is incomplete.

How is selective breeding and genetic engineering used to produce organisms with desired characteristics.

• Both selective breeding and genetic engineering are used to produce organisms with desired characteristics.

• Both aim to improve useful traits, such as disease resistance or increased yield.

• Selective breeding involves choosing parents with desirable characteristics and breeding them over many generations.

• Genetic engineering involves directly inserting a desired gene into an organism's DNA.

• Selective breeding uses existing genes within a species, whereas genetic engineering can transfer genes from a different species.

• Genetic engineering is usually faster and more precise than selective breeding.

How does evolution occur?

• Variation exists within a population.

• Some individuals have advantageous characteristics.

• These individuals are more likely to survive.

• They reproduce successfully.

• Their alleles are passed to offspring.

• Over many generations, the advantageous allele becomes more common.

Effects of Deforestation

• Trees are removed from forests.

• Less photosynthesis occurs.

• Less carbon dioxide is removed from the atmosphere.

• Burning or decay releases carbon dioxide.

• Habitats are destroyed.

• Biodiversity decreases.

Intensive vs Extensive Farming

• Intensive farming uses more machinery, chemicals and energy.

• It produces higher yields.

• Extensive farming uses larger areas with fewer inputs.

• Intensive farming may damage habitats.

• Extensive farming is often less productive.

• Both aim to increase food production.

Adaptations

• Adaptations increase chances of survival.

• Structural adaptations are physical features.

• Behavioural adaptations affect actions.

• Functional adaptations affect internal processes.

• Adaptations help organisms compete successfully.

• Adapted organisms are more likely to reproduce.

Decay and Factors Affecting Rate

• Decay is caused by microorganisms.

• Microorganisms digest dead material.

• Enzymes control decay reactions.

• Warm temperatures increase enzyme activity.

• Water is needed for microorganisms.

• Oxygen is needed for aerobic decay.