Year 9 Science: Plant Biology Revision 2024

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Questions and Answers

What is the primary function of the nucleus in a cell?

Storage of genetic information (correct)

Energy production

Cellular respiration

Protein synthesis

What is a gene?

A type of molecule involved in energy production

A subcomponent of a chromosome storing proteins

A unit of heredity that contributes to a person’s characteristics (correct)

A cellular organelle responsible for metabolism

Which statement best describes the structure of DNA?

A spherical arrangement of proteins and lipids

A double helix composed of nucleotide pairs (correct)

A rigid, unbranching chain of nucleic acids

A linear sequence of amino acids

What do inheritable traits primarily rely upon?

Combinations of genes from parents Signup and view all the answers

What is the role of gametes in reproduction?

They fuse to form a zygote, creating genetic diversity Signup and view all the answers

Which process describes how a fertilized egg develops into a fetus?

Cell differentiation and organ development Signup and view all the answers

What determines the sex of a baby?

The male gamete (sperm) that fertilizes the egg Signup and view all the answers

How does smoking during pregnancy affect fetal development?

Restricts oxygen and nutrient supply to the fetus Signup and view all the answers

What is the primary purpose of photosynthesis in plants?

To synthesize glucose from sunlight Signup and view all the answers

Which mineral is essential for chlorophyll production in plants?

Magnesium Signup and view all the answers

What are the consequences of nitrate deficiency in plants?

Reduced growth and yellowing of leaves Signup and view all the answers

What is the word equation for photosynthesis?

Carbon dioxide + Water → Glucose + Oxygen Signup and view all the answers

Which process describes the loss of water vapor from plant leaves?

Transpiration Signup and view all the answers

What is a key component of the carbon cycle that involves organisms breaking down organic matter?

Decomposition Signup and view all the answers

Which part of the kidney is responsible for filtering blood?

Renal cortex Signup and view all the answers

What is urea and how is it formed in the human body?

A waste product formed from the breakdown of proteins Signup and view all the answers

Which product is formed when copper reacts with hydrochloric acid?

Hydrogen gas Signup and view all the answers

What is the result of the reaction between magnesium carbonate and sulfuric acid?

Magnesium sulfate Signup and view all the answers

How does increasing temperature affect the rate of a chemical reaction according to particle collision theory?

It increases particle collisions Signup and view all the answers

Which factor does NOT affect the rate of a chemical reaction?

The color of the reactants Signup and view all the answers

What is the primary difference between a chemical reaction and a physical reaction?

Chemical reactions involve the creation of new substances Signup and view all the answers

When sodium reacts with nitric acid, which of the following products is NOT typically formed?

Sodium hydroxide Signup and view all the answers

Which of the following is a correct statement about the relationship between density, mass, and volume?

Liquids have greater density than gases Signup and view all the answers

What is the likely result of a reaction between calcium carbonate and hydrochloric acid?

All of the above Signup and view all the answers

What trend occurs in atomic size as you move down group 1 in the periodic table?

Atomic size increases. Signup and view all the answers

Which statement best describes the reactivity of elements down group 7?

Reactivity decreases as you move down the group. Signup and view all the answers

What is the primary force that holds protons together in the nucleus?

Strong nuclear force. Signup and view all the answers

How do the electronic configurations change as you go down group 1?

They gain additional electron shells. Signup and view all the answers

What happens when lithium, sodium, and potassium react with water?

Potassium reacts more violently than sodium. Signup and view all the answers

What is the law of conservation of mass?

The total mass of reactants equals the total mass of products. Signup and view all the answers

Why is sodium stored in oil?

To avoid contact with moisture. Signup and view all the answers

What is the result of the reaction between magnesium and copper sulfate?

Copper is produced along with magnesium sulfate. Signup and view all the answers

How might the construction of a road through a national nature reserve affect a rare butterfly species dependent on a specific flower?

Butterflies may become extinct due to their inability to cross the road. Signup and view all the answers

What is a possible consequence of environmental changes for a species unable to adapt?

The species may face extinction. Signup and view all the answers

Which factor is critical for the survival of the butterfly species in the reserve?

The availability of pink flowers. Signup and view all the answers

Which of the following best describes a negative impact of habitat fragmentation on species?

Isolated populations leading to inbreeding. Signup and view all the answers

What strategy might butterflies employ when faced with environmental changes such as habitat loss?

Seek different migratory paths. Signup and view all the answers

Why might adult butterflies and larvae on both sides of the road still face extinction despite food availability?

The road limits their movement and food access. Signup and view all the answers

Which of the following illustrates the concept of a critical dependency for species survival?

A species reliant solely on one type of flower for nourishment. Signup and view all the answers

In the scenario of the butterflies, what can be inferred about the relationship between environmental change and species adaptability?

Specialized species are at greater risk when environments change. Signup and view all the answers

Study Notes

Plant Biology

Life processes include movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition.
Magnesium is crucial for chlorophyll production, affecting a plant's ability to photosynthesize.
Nitrates provide essential nitrogen for proteins and nucleic acids, promoting healthy growth.
Magnesium deficiency leads to yellowing leaves and stunted growth due to impaired photosynthesis.
Nitrate deficiency results in poor growth, yellowing leaves, and reduced protein production.
Photosynthesis converts light energy into chemical energy, producing glucose and oxygen.
The word equation for photosynthesis: Carbon dioxide + Water → Glucose + Oxygen.
Chloroplasts are organelles in plant cells where photosynthesis occurs.
Chlorophyll is the pigment that absorbs light energy for photosynthesis.
The primary carbohydrate produced is glucose.
During photosynthesis, light energy is transformed into chemical energy stored in glucose.
Transpiration is the process of water vapor loss from plants, mainly through stomata.
Water and minerals travel from root hair cells through the xylem to leaves, where transpiration occurs.
Root hair cells have elongated structures to increase surface area for water absorption.
The phloem tissue transports sugars (products of photosynthesis) in plants.
The carbon cycle includes processes like photosynthesis, respiration, feeding, decomposition, and combustion.
Photosynthesis captures carbon dioxide, while respiration releases it back into the atmosphere.
Photosynthetic organisms (plants, algae) take in carbon dioxide; respiratory organisms (animals, plants) release it.
Fossil fuels are natural substances formed from decomposed plants and animals, releasing carbon dioxide when burned.
Combustion of fossil fuels increases atmospheric carbon dioxide, contributing to climate change; stopping burning could stabilize carbon levels.

Maintaining Life

Humans excrete products like urea, carbon dioxide, and water.
Excretory products originate from metabolic processes, including protein breakdown and cellular respiration.
The human excretory system consists of kidneys, ureters, bladder, and urethra.
Kidneys filter blood, excreting waste dissolved in urine while retaining necessary substances.
Urea, a nitrogenous waste, is formed in the liver from excess amino acids.
Unhealthy kidney neglect can lead to dysfunction; hydration and a balanced diet can help maintain kidney health.
Dialysis is a medical procedure that artificially removes waste products and excess fluid from the blood.
A fetus is a developing human from the end of the 8th week of pregnancy until birth, and a zygote is the fertilized egg formed when sperm and egg fuse.
Fetal development refers to the stages from fertilization through growth until birth, including organ formation.
Excess healthy food can lead to nutrient imbalances, harming health.
Functions of minerals: Iron (oxygen transport), Calcium (bone health), Potassium (nerve function), Zinc (immune support).
Smoking during pregnancy risks fetal growth and development, as harmful substances cross the placenta.

Genetics and Inheritance

The nucleus contains genetic material and regulates cell activities.
A gene is a segment of DNA encoding a specific trait. DNA is a double helix structure made of nucleotides; chromosomes are DNA packaged in structures.
DNA is tightly coiled to fit within the nucleus, known as chromatin when uncoiled.
James Watson and Francis Crick discovered DNA's structure using X-ray diffraction data.
DNA's significance lies in coding for proteins, essential for cell structure and function.
Genes dictate physical traits, leading to variations influenced by different gene combinations.
Gametes (sperm and egg) are reproductive cells; somatic cells are all other body cells.
Male gametes (sperm) carry X or Y chromosomes; female gametes (eggs) carry X chromosomes.
A fertilized egg (zygote) results from the fusion of gametes, introducing a mix of parental DNA.
Environmental changes may lead to species extinction if they can't adapt; for example, habitat loss can isolate populations.
A fragmented habitat restricts movement and access to resources, leading to decreased survival rates.

Chemical Bonding

A molecule is formed when two or more atoms bond chemically.
Diatomic molecules consist of two identical atoms, while compounds contain different elements.
Elements are pure substances, while compounds are combinations of different elements.
Examples: Elements - oxygen, carbon, gold; Compounds - water, carbon dioxide, sodium chloride; Molecules - H2O, O2, N2.
A covalent bond involves the sharing of electron pairs between atoms; e.g., water (H2O).
Ions are charged particles; sodium forms Na⁺ by losing an electron, while magnesium forms Mg²⁺ by losing two electrons.
Chlorine gains an electron to form Cl⁻; oxygen gains two to form O²⁻, whereas neon is stable and does not form ions.
An ionic bond forms when one atom donates an electron to another; sodium chloride (NaCl) is a classic ionic compound.
Magnesium sulfate (MgSO₄) is ionic due to its formation from magnesium and sulfate ions, with “ate” indicating its polyatomic nature.

Chemical Structures and Properties

An atom consists of protons, neutrons, and electrons; atomic number equals the number of protons.
Atomic mass is the number of protons plus neutrons.
Rutherford's model introduced the nucleus; Bohr proposed electron orbitals.
Periodic table organizes elements by groups and periods, showing trends in reactivity and properties across periods and groups.
Group 1 elements increase reactivity down the group; Group 7 shows decreasing reactivity.
Alkali metals react vigorously with water; lithium, sodium, and potassium produce hydrogen gas upon reaction.
Atomic radius increases down group 1 due to added electron shells, while electronic configurations change accordingly.

Chemical Reactions

A chemical reaction involves the transformation of reactants into products, evidenced by color change, gas production, or temperature change.
Chemical reactions require collisions between reacting particles with sufficient energy.
Temperature, surface area, and concentration affect reaction rates; higher temperatures increase energy and collision frequency, enhancing reaction rates.
Conservation refers to the principle that matter and energy cannot be created or destroyed in a reaction.
The law of conservation of energy states that energy is not lost but transformed, while the law of conservation of mass states total mass remains constant in a closed system.
Copper sulfate can be synthesized through a reaction method involving excess copper oxide and sulfuric acid, producing blue crystals as a salt result.

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Description

This quiz focuses on the essential concepts from Cambridge Unit 9.2 regarding Plant Biology, including photosynthesis and the carbon cycle. Test your understanding of life processes, the role of magnesium and nitrates in plant growth, and the effects of deficiencies. Perfect for Year 9 EOY revision!