Grade 8 Exam Practice Question's
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Questions and Answers

What is an example of a behavioural adaptation that helps animals avoid predators?

  • Changing color to blend in with the environment
  • Sweating
  • Freezing when predators come near (correct)
  • Hibernation

    • What type of activity pattern helps animals avoid unfavorable conditions?

  • Crepuscular
  • Nocturnal (correct)
  • Diurnal
  • Hibernation

    • What is a source of variation within a species?

  • Mutations
  • Environmental factors
  • Diet
  • All of the above (correct)

    • What happens to favourable characteristics through successful reproduction?

    <p>They become the most common</p> Signup and view all the answers

    What process leads to favourable characteristics becoming more common in a population?

    <p>Natural selection</p> Signup and view all the answers

    What is the term for the process by which different species develop similar characteristics in response to similar environmental pressures?

    <p>Parallel evolution</p> Signup and view all the answers

    What is the term for an allele that will always be expressed if an individual has one copy of it?

    <p>Dominant allele</p> Signup and view all the answers

    What is the term for the physical expression of a gene?

    <p>Phenotype</p> Signup and view all the answers

    What is the term for having two different alleles of a gene?

    <p>Heterozygous</p> Signup and view all the answers

    What is the term for two or more different forms of a gene?

    <p>Alleles</p> Signup and view all the answers

    What type of inheritance results in a phenotype that is a blend of a heterozygous allele pair?

    <p>Incomplete dominance</p> Signup and view all the answers

    What is a characteristic of asexual reproduction?

    <p>Offspring have 100% the same chromosomes as the parent</p> Signup and view all the answers

    What is the purpose of a Punnett square?

    <p>To determine the genotype and phenotype ratios of a cross</p> Signup and view all the answers

    What is the process by which organisms with unfavorable characteristics die off, becoming less common?

    <p>Natural selection</p> Signup and view all the answers

    What is the term for the survival of organisms with favorable characteristics, leading to their increased representation in a population?

    <p>Survival of the fittest</p> Signup and view all the answers

    What is the result of variation in characteristics within a species, leading to the selection of favorable traits?

    <p>Natural selection</p> Signup and view all the answers

    What is the term for similar structures in related species, resulting from shared genetic heritage?

    <p>Homologous structures</p> Signup and view all the answers

    What type of evolution occurs when organisms from different origins evolve similar adaptations?

    <p>Convergent evolution</p> Signup and view all the answers

    What is the primary function of the 'fight or flight' response?

    <p>To prepare the body for perceived threat or danger</p> Signup and view all the answers

    Which hormone is responsible for converting blood glucose to glycogen in the liver?

    <p>Insulin</p> Signup and view all the answers

    What is the fundamental unit of life, according to the cell theory?

    <p>Cell</p> Signup and view all the answers

    What is the result of the release of adrenaline and norepinephrine from the adrenal glands?

    <p>Increased heart rate and breathing</p> Signup and view all the answers

    Which of the following is a characteristic of all living things, according to the cell theory?

    <p>They are all composed of cells</p> Signup and view all the answers

    What is the function of the hormone glucagon?

    <p>To convert glycogen back to glucose</p> Signup and view all the answers

    What is the term for the physical structure of a cell?

    <p>Cell structure</p> Signup and view all the answers

    Which of the following is a characteristic of multicellular organisms?

    <p>They are all composed of specialized cells</p> Signup and view all the answers

    What is the primary function of the pancreas?

    <p>To produce hormones that regulate blood sugar levels</p> Signup and view all the answers

    What is the term for the process by which an organism's body responds to perceived threat or danger?

    <p>Fight or flight response</p> Signup and view all the answers

    What is the process of asexual reproduction where a new individual develops from an outgrowth of a parent?

    <p>Budding</p> Signup and view all the answers

    Which organism is an example of asexual reproduction that occurs through spores?

    <p>Fungi</p> Signup and view all the answers

    What is the process of asexual reproduction where a single parent breaks into parts that regenerate into whole new individuals?

    <p>Fragmentation</p> Signup and view all the answers

    Which type of reproduction requires two parents that each share ½ of the genetic information?

    <p>Sexual Reproduction</p> Signup and view all the answers

    What is the type of asexual reproduction in which the offspring develops from the egg or female gamete without being fertilized by the male gamete?

    <p>Parthenogenesis</p> Signup and view all the answers

    What is the main purpose of camouflage in an organism's adaptation to its environment?

    <p>To blend into its surroundings and avoid predators</p> Signup and view all the answers

    What is the result of genetic mutations and natural selection in a population?

    <p>The inheritance of favourable characteristics</p> Signup and view all the answers

    What is an example of a functional adaptation in an organism?

    <p>The ability to contract muscles when stimulated</p> Signup and view all the answers

    Why are smaller animals more suited to very hot climates?

    <p>Because they have a larger surface area to volume ratio</p> Signup and view all the answers

    What is the primary function of connective tissue in the body?

    <p>To provide structural support and protection</p> Signup and view all the answers

    What is the primary function of the pituitary gland in the endocrine system?

    <p>To produce hormones that stimulate or suppress other endocrine glands</p> Signup and view all the answers

    What is the role of the thyroid hormone thyroxine?

    <p>To regulate the rate of metabolism</p> Signup and view all the answers

    How do hormones act on the body?

    <p>They act slowly but have long-lasting effects</p> Signup and view all the answers

    What is the role of the hypothalamus in the endocrine system?

    <p>To produce chemicals that stimulate or suppress hormone secretions</p> Signup and view all the answers

    What is the term for the process of maintaining the body's internal environment?

    <p>Homeostasis</p> Signup and view all the answers

    What is the purpose of insulation in some animals?

    <p>To regulate body temperature</p> Signup and view all the answers

    What is the result of genetic mutations and natural selection in a population?

    <p>The adaptation of organisms to their environment</p> Signup and view all the answers

    What is the term for physical features of an organism that aid in its survival?

    <p>Structural adaptations</p> Signup and view all the answers

    What is the role of muscle tissue in the body?

    <p>To contract when stimulated by nerve impulses</p> Signup and view all the answers

    What is the role of the pancreas in regulating blood sugar levels?

    <p>To produce insulin and glucagon</p> Signup and view all the answers

    What is the effect of the release of adrenaline and norepinephrine from the adrenal glands?

    <p>Constriction of blood vessels and increase in heart rate</p> Signup and view all the answers

    What is the function of the hormone glucagon in the liver?

    <p>To convert glycogen back to glucose</p> Signup and view all the answers

    What is the consequence of a deficiency in the adrenal glands' function?

    <p>Weight gain and sluggishness</p> Signup and view all the answers

    What is the term for a change that occurs around us in the environment?

    <p>Stimulus</p> Signup and view all the answers

    What is the primary function of the endocrine system?

    <p>To produce and regulate hormones</p> Signup and view all the answers

    What is the significance of homeostasis in the body?

    <p>It maintains a constant internal environment</p> Signup and view all the answers

    Which part of the nervous system consists of the brain and spinal cord?

    <p>Central Nervous System (CNS)</p> Signup and view all the answers

    What is the consequence of homeostasis failure?

    <p>The body may become ill or die</p> Signup and view all the answers

    What is the primary function of the signal interpretation process in organisms?

    <p>To respond to stimuli and initiate behaviours</p> Signup and view all the answers

    What is the purpose of shivering when an animal is cold?

    <p>To generate heat and warm the body</p> Signup and view all the answers

    What is the result of variation in characteristics within a species?

    <p>The selection of favorable traits</p> Signup and view all the answers

    What is an example of a functional adaptation that helps an organism survive in its environment?

    <p>Sweating to cool down</p> Signup and view all the answers

    What is the result of genetic mutations and natural selection in a population?

    <p>The selection of favorable traits</p> Signup and view all the answers

    What is the main purpose of an organism's adaptation to its environment?

    <p>To increase its chances of survival and reproduction</p> Signup and view all the answers

    What is an example of a stimulus that can be detected by the skin?

    <p>Heat</p> Signup and view all the answers

    What is the primary function of hormones in the body?

    <p>To regulate growth and development, mood, tissue function, metabolism, and sexual function</p> Signup and view all the answers

    What is the role of the hypothalamus in the endocrine system?

    <p>To produce releasing hormones that stimulate the pituitary gland</p> Signup and view all the answers

    What is the effect of excess thyroxine produced by the thyroid gland?

    <p>Hyperactivity</p> Signup and view all the answers

    How do hormones act on the body compared to nervous impulses?

    <p>Hormones act slower and cause longer-lasting effects</p> Signup and view all the answers

    What is the purpose of the mechanism of homeostasis in the body?

    <p>To maintain a constant internal environment</p> Signup and view all the answers

    What is the function of the endocrine system in the body?

    <p>To produce and regulate hormones</p> Signup and view all the answers

    What is the difference between the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)?

    <p>The CNS consists of the brain and spinal cord, while the PNS consists of nerve cells</p> Signup and view all the answers

    What happens when an organism's internal environment is not maintained at a constant level?

    <p>The organism may become ill or even die</p> Signup and view all the answers

    What is the purpose of the mechanism of ignoring certain stimuli?

    <p>To focus on more important stimuli</p> Signup and view all the answers

    What is the primary function of functional adaptations in an organism?

    <p>To help the organism survive and reproduce in its environment</p> Signup and view all the answers

    Which of the following is an example of a behavioural adaptation?

    <p>Freezing when predators come near</p> Signup and view all the answers

    What is the result of variation in characteristics within a species?

    <p>Variation can either help or hinder an organism in its environment</p> Signup and view all the answers

    What is the purpose of an organism's ability to change colour?

    <p>To blend in with the environment</p> Signup and view all the answers

    What is an example of an adaptation that helps an organism conserve energy?

    <p>Hibernation in winter</p> Signup and view all the answers

    How do plants respond to sunlight?

    <p>By growing towards sunlight</p> Signup and view all the answers

    What type of stimuli can the skin detect?

    <p>Heat, cold, pressure, and pain</p> Signup and view all the answers

    What is the term for the physical features of an organism that aid in its survival?

    <p>Structural adaptation</p> Signup and view all the answers

    What is the purpose of insulation in some animals?

    <p>To regulate body temperature</p> Signup and view all the answers

    What is the result of genetic mutations and natural selection in a population?

    <p>Adaptations that aid in survival</p> Signup and view all the answers

    What is the function of camouflage in an organism's adaptation to its environment?

    <p>To blend in with surroundings</p> Signup and view all the answers

    What is the main difference between structural and functional adaptations?

    <p>Structural adaptations are physical, while functional adaptations are behavioral</p> Signup and view all the answers

    What is the response of an animal to a stimulus that causes it to contract its muscles?

    <p>Reflex action</p> Signup and view all the answers

    What is an advantage of asexual reproduction?

    <p>It takes less time</p> Signup and view all the answers

    What is a disadvantage of asexual reproduction?

    <p>The same DNA is produced in more offspring</p> Signup and view all the answers

    What is the main difference between asexual and sexual reproduction?

    <p>Asexual reproduction produces genetically identical offspring, while sexual reproduction produces genetically diverse offspring</p> Signup and view all the answers

    What is the benefit of asexual reproduction in terms of genetic information?

    <p>It produces offspring with the same genetic information</p> Signup and view all the answers

    What is the main advantage of asexual reproduction in terms of time?

    <p>It takes less time to produce offspring</p> Signup and view all the answers

    What is the difference between asexual and sexual reproduction in terms of parents involved?

    <p>Asexual reproduction requires one parent, while sexual reproduction requires two parents</p> Signup and view all the answers

    What is the term for the process where organisms with favorable characteristics are more likely to survive and reproduce?

    <p>Natural selection</p> Signup and view all the answers

    What is the term for the phenomenon where different species evolve from a single ancestor?

    <p>Divergent evolution</p> Signup and view all the answers

    What is the term for the process where organisms from different origins evolve similar adaptations?

    <p>Convergent evolution</p> Signup and view all the answers

    What is the term for the survival of organisms with favorable characteristics, leading to their increased representation in a population?

    <p>Survival of the fittest</p> Signup and view all the answers

    Why did ancestral giraffes with longer necks survive and produce long-necked offspring?

    <p>Because they could reach food that others could not</p> Signup and view all the answers

    What is the primary reason why organisms develop adaptations?

    <p>To increase their chances of survival and breeding</p> Signup and view all the answers

    What is the main difference between structural and functional adaptations?

    <p>One is related to physical features and the other is related to internal functions</p> Signup and view all the answers

    What is the outcome of natural selection and genetic mutations in a population?

    <p>The selection of favorable traits</p> Signup and view all the answers

    What is the purpose of hibernation in some animals?

    <p>To reduce metabolism and conserve energy during periods of food scarcity</p> Signup and view all the answers

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