Science Reviewer Past Paper cher VI PDF

Science Reviewer ‘cher Vi  A plant grows towards a window. This is an example of: A. Reproduction B. Growth and Development C. Response to Stimuli. D. Metabolism A scientist observes that a certain type of bacteria grows faster in warm temperatures. She hypothesizes that temperature affe...

Science Reviewer ‘cher Vi  A plant grows towards a window. This is an example of: A. Reproduction B. Growth and Development C. Response to Stimuli. D. Metabolism A scientist observes that a certain type of bacteria grows faster in warm temperatures. She hypothesizes that temperature affects bacterial growth rate. To test this hypothesis, she should: A. Observe the bacteria in different environments B. Grow the bacteria at different temperatures and measure growth rates. C. Read about bacterial growth in textbooks D. Ask other scientists about their opinions A researcher claims that a certain type of plant can purify polluted water. Before believing the claim, which of the following would be the most critical factor to evaluate? A. The plant's appearance and growth rate B. The researcher’s reputation C. The experimental methods used to test the plant’s ability to purify water. D. The color of the plant’s flowers Which of the following statements about the light- dependent reactions of photosynthesis is accurate? A. They occur in the stroma of the chloroplast B. They convert sunlight into chemical energy stored in ATP and NADPH. C. They produce glucose from carbon dioxide and water D. They do not require sunlight to function  Which of the following is a form of asexual reproduction? A.Binary fission. B.Pollination C.Fertilization Reese MillerD.Internal fertilization Sandra Haro Helene Paquet  Which process involves the division of a cell into two genetically identical daughter cells? A. Mitosis. B. Meiosis C. Fertilization D. Cross-pollination Biosphere What is the term used to describe organisms that produce both male and female gametes? A. Hermaphrodites. B. Gametophytes C. Sporophytes D. Monoecious  How does the process of meiosis contribute to the concept of genetic inheritance? A.Meiosis produces cells with half the genetic material, ensuring that offspring inherit genetic material from both parents. B.Meiosis results in the replication of the entire genome, maintaining genetic stability. C.Meiosis leads to mutations that cause genetic changes D.Meiosis results in the production of genetically identical cells Which of the following is an example of an adaptation that helps animals survive in cold environments? A. Bright-colored fur B. Thick fur or blubber. C. Large ears D. Webbed feet  Why do desert animals often have large ears? A. To help them hear better in the dark B. To increase body surface area for cooling. C. To scare away predators D. To store water Igneous If you were studying a species of bird in a tropical rainforest, which of the following features would most likely help it survive in that environment? A. Small, compact body B. Ability to migrate long distances. C. Camouflaged feathers Reese Miller D. A Sandra thickHaro coat of fur Helene Paquet  Which of the following statements best explains the relationship between the size of an animal's body and its ability to conserve heat in cold environments? A. Larger animals tend to lose heat more quickly due to their higher metabolic rates B. Smaller animals conserve heat better due to their smaller surface area to volume ratio. C. Larger animals conserve heat better because they have a greater body surface area D. There is no relationship between body size and heat conservation You are given two species of animals: one lives in a forest and the other in a desert. Which of the following is the best indicator that the forest- dwelling species is more likely to have evolved to avoid predators? A. The animal has sharp teeth for fighting B. The animal has a keen sense of smell to detect predators C. The animal has bright colors to warn predators of its toxicity D. The animal has camouflage to blend in with its environment. Imagine you are designing an animal that can survive in both a forest and a desert environment. Which of the following features would be most essential for this animal's survival? A. Long, thick fur to retain heat B. Ability to store water in its body. C. Bright-colored feathers for attracting mates D. A large, muscular build to fight predators  You are growing plants in a greenhouse. To ensure the plants get enough water and prevent wilting, which strategy would be most effective? A. Increase light intensity B. Ensure proper drainage and water absorption by the roots. C. Cut back the leaves to reduce water loss D. Increase the temperature to speed up growth  Given that plants need to adapt to their environment to survive, which of the following adaptations would you consider most effective for a plant growing in a region with frequent wildfires? A. Thick, fire-resistant bark. B. Deep roots that access underground water C. A thick waxy coating on leaves to retain moisture D. Brightly colored flowers to attract pollinators  What mechanism of evolution involves the survival and reproduction of individuals with advantageous traits? A. Genetic drift B. Gene flow C. Natural selection. Reese Miller Sandra Haro Helene Paquet D. Mutation  Why is genetic variation important in the process of evolution? A. It reduces the chance of survival for the population B. It ensures that all individuals are identical C. It provides the raw material for natural selection to act upon. D. It eliminates the need for mutations  A farmer selectively breeds cows to produce more milk. This is an example of: A. Natural selection B. Artificial selection. C. Genetic drift D. Speciation Pressure  The population of beetles includes green and brown individuals. If a predator prefers green beetles, what is the most likely outcome for the population over time? A. Green beetles will become more common due to predation B. Brown beetles will have a higher survival rate, increasing their frequency. C. Predation will not affect the beetle population D. Both green and brown beetles will disappear entirely Break a leg! Parts of the Cell Which is which? Cell  considered the basic units of life in part because they come in discrete and easily recognizable packages.  Trees in a forest  fish in a river  horseflies on a farm  worms in the soil s covered with a membrane that allows materials to pass in and out, it’s often called the ter” of the cell because it contains DNA. Nucleus This round organelle is in the center of the cell. It controls all the activities of the organism. It’s often called the “control center” of the cell because it contains DNA.  Vacuole A vacuole is the storage area of the cell. Vacuoles store water, food, and waste.  Golgi Apparatus It is the part that helps process and package proteins and lipid molecules in the animal and plant cell.  Lysosome Lysosomes are organelles that help break down certain materials inside the cell.  Ribosome Ribosomes are the protein factories of the cell. These are very essential since all the functions and processes in plant and animal cell requires protein. Even all the organelles inside the cell are made up of proteins making ribosomes very important.  Cell Membrane The cell membrane is a semi- permeable membrane that facilitate the movement of molecules inside and outside the plant or animal cell.  Cytoplasm The cytoplasm is a viscous fluid or jelly like material where organelles are embedded. Its jelly like feature secures the organelles in plants and animals so that they remain place.  Mitochondria The mitochondria are called the “powerhouses” of cells. They produce much of the energy a plant or animal cell needs to carry out its function. Endoplasmic Reticulum The endoplasmic reticulum (ER) is a series of tunnels throughout the cytoplasm. They transport proteins from one part of the cell to another, that is why they are called as the transport center of the cell.  Endoplasmic Reticulum Smooth- ribosome free and function in detoxification of lipids. Rough- contains ribosomes and releases newly made protein from the cell.  Chloroplast It is the part that produces food in a plant cell.  Plastids Plastids are double membrane bound organelles found in plants. It is basically the storage of their pigments.  Cell Wall It is the protective part of the plant cell. It gives the plant cell its rectangular shape.  Bioenergetics PHOTOSYNTHE SIS  What is photosynthesis? A chemical process which occurs in plants using light energy, where carbon dioxide and water produces glucose and oxygen.  Where does Chloroplas photosynthesis t occur? Light energy is absorbed by a green pigment called chlorophyll in leaves. Chlorophyll is located in the chloroplasts. Chloroplasts are organelles found in plant cells, particularly cells on the surface of the leaf such as palisade cells.  Photosynthesis equation carbon dioxide + water glucose + oxygen  Carbon dioxide and water The carbon dioxide required for Stoma photosynthesis is in the air. It enters the leaves through the stomata (tiny holes controlling gas exchange). Water enters the plant through the roots and is transported up the plant to the Guard cell leaves via the xylem in the stem. The oxygen formed is a waste product but some can be used for  Factors affecting photosynthesis Light The amount Temperature intensity of chlorophyll The time of day Climate change Some plant and time of year affects temperature. diseases can affect the intensity Photosynthesis is damage cells and of light. Some generally optimum consequently seasons are better between 15-40 chlorophyll, for photosynthesis. degrees Celsius. affecting photosynthesis.  Factors affecting photosynthesis Amount of carbon Amount of water dioxide If the concentration of carbon Plants need water to dioxide increases, so does the rate photosynthesize but it may be a of photosynthesis. limiting factor in extreme rainy or hot weather. PARTS OF THE FLOWER  Sepal Sepals are the exterior parts of a flower that protect the interior flower while it emerges. Sepals are typically green and leaf-like that enclose developing bud.  Petals Petals exist to draw pollinators to the flower. It is for this reason that they are often brightly colored, showy, and of interesting patterns and sizes. Stamen The stamen is the male reproductive organ of a flower.  Filament- supports the Anther  Anther- produces Pollen Grains Pistil The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma.  Reproduction in Plants Reproduction is the process by which an organism produces its own kind to ensure that its species lives on. If organisms of a certain kind do not reproduce, their species will gradually diminish until they cease to exist. REPRODUCTION IN PLANTS SEXUAL REPRODUCTION ASEXUAL REPRODUCTION  Pollination Reproduction in flowering plants starts with pollination, or the transfer of the pollen from the anther to the stigma. Pollination  ASEXUAL REPRODUCTION In plants, as some organs grow indeterminately due to tissues that can actively divide and revert to non- specialized structures. This indeterminate growth can lead to a form of reproduction called asexual reproduction, as these organs can separate from the parent plant with the ability to grow and develop. ARTIFICIAL METHODS OF ASEXUAL Grafting Cutting Layering Micropropagation  ARTIFICIAL METHODS OF ASEXUAL 1. Grafting has long been used to produce novel varieties of roses, citrus species, and other plants. ARTIFICIAL METHODS OF ASEXUAL 2. Cutting Plants are propagated through stem cuttings where a portion of the stem containing nodes and internodes is placed in moist soil and allowed to root.  ARTIFICIAL METHODS OF ASEXUAL 3. Layering A method in which a stem attached to the plant is bent and covered with soil. ARTIFICIAL METHODS OF ASEXUAL 4. Micropropagation (also called plant tissue culture) is a method of propagating a large number of plants from a single plant in a short time under laboratory conditions. ARTIFICIAL METHODS OF ASEXUAL 4. Micropropagation (also called plant tissue culture) is a method of propagating a large number of plants from a single plant in a short time under laboratory conditions.  ANIMAL REPRODUCTION SEXUAL REPRODUCTION The perpetuation of a new organism from two organisms with the use of gametes.  INTERNAL FERTILIZATION Involves the fusion of the male and the female gamete inside the female body. Chances of the survival of the offspring are more. Therefore, a small number of eggs are produced. Ex. Humans, cows, hens  EXTERNAL FERTILIZATION Involves the fusion of the male and the female gamete outside the female body. Chances of survival of the offspring are less. Therefore, a large number of eggs are produced. Ex, Fish, frog GENETICS What are genes? Genes are small units of information inside our cells that contain instructions for how our bodies develop and function. They 'code' for traits like our eye color, hair color, and height.  What is DNA? DNA is a molecule that carries genetic information in living organisms. It looks like a twisted ladder (double helix) and is found inside the nucleus of our cells. DNA stands for deoxyribonucleic acid. P Where do our genes hang out? q Genes are segments of DNA located on structures called chromosomes. Chromosomes are long, thread-like structures made up of DNA and proteins. They carry many genes and are found inside the nucleus of our cells. FUN FACT Humans typically have 46 chromosomes, which come in pairs, with 23 inherited from each parent. Why do we need genes? We need genes because they contain the instructions for building and maintaining our bodies. They also have crucial role in passing traits from parents to children through reproduction. Genetic Engineering also known as ”Genetic Modification” It is the science that of identifying, isolating and altering genes. Recombinant DNA technology – The introduction of a gene from one organism into another. Gene Splicing- To isolate a gene, scientist use this technique. GMO(Genetically modified Organism)- The organism bearing the recombinant DNA. TYPES OF GENETIC MODIFICATION Plant Genetic Modification Animal Modification Genetic Modification of Microbes Types of Genetic Modification PLANT GENETIC MODIFICATION The easiest method of plant genetic modification used by wandering ancestors.  Types of Genetic Modification ANIMAL MODIFICATION Modern breeds of livestock differ dramatically from their ancestors as a result of breeding strategies. Types of Genetic Modification GENETIC MODIFICATION OF MICROBES Microorganisms play significant roles in food production.  Food, wine, breed and cheese are common examples of ancient foods, still popular, depend on microbial ingredients and activities.