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WorksheetsJan 2024 Part A Practice
Total questions: 30
Worksheet time: 3600secs
Internal balance in unicellular organisms is maintained through the proper functioning of
organelles
estrogen
guard cells
antibodies
In a stable ecosystem, usually only one species occupies each habitat. The species that occupies a particular habitat is able to survive there as a direct result of
ecological succession
appropriate adaptations
a new mutation
artificial selection
When human skin cells are exposed to ultraviolet (UV) rays, they produce the protein melanin. This protein helps protect skin cells from damage caused by ultraviolet rays. This is an example of
A gene that cannot be passed to offspring
Natural selection that produces a new species
Sexual reproduction that will produce diversity
The effect of environmental factors on gene expression
The human pancreas contains cells that secrete insulin. Only these cells produce insulin because
The cells get rid of parts of the genetic code they do not use
All other cells lack the genes responsible for insulin production
Different cells use different parts of the genetic information they contain
Because they are the only cells associated with sugar digestion
In humans, two organ systems work together to transport oxygen throughout the body and deliver it to the cells. Which system delivers oxygen directly to the body’s cells?
Nervous
Digestive
Respiratory
Circulatory
Currently, turtle populations are declining. In September 2018, a scientist stated that turtles contribute to the health of many environments, and that the decline in turtle numbers could lead to negative effects on other species.
Which of the following statements best summarizes the scientist's statement?
Living organisms interact with their environment and depend on it and on each other.
Turtles are very large animals and therefore have a negative impact on their environment wherever they live.
If living organisms have a negative impact on their environment, there is often a technological solution available.
The decline in turtle numbers will not be very significant because few people rely on them as a food source.
Which group of substances are the molecular building blocks that directly form some of the complex organic molecules found in humans?
Water and oxygen
Starch and nitrogen
Carbon dioxide and proteins
Glucose and amino acids
The diagram represents a process that occurs in many cells.
The main function of this process is
Producing diversity in cells before asexual reproduction
Synthesizing antigens needed for immune response
Providing identical copies of the genetic code before cell division
Making proteins needed for cellular metabolism
Which interaction is an example of competition between two species of organisms?
Mice and squirrels eat sunflower seeds at a bird feeder
Mold growing on a tree that has fallen in the forest
A coyote feeds on the remains of a squirrel killed on the road
A lion chases, kills, and eats a zebra
One important reason why humans have a significant impact on Earth's ecosystems is that humans
remove large amounts of carbon dioxide from the air
are able to increase the amount of limited resources
can modify the environment through technology
reproduce faster than other animal species
Mutations can be beneficial to a species because
They can lead some individuals of the species to have advantageous traits in a changing environment
They allow organisms to mate with other species
They will result in the loss of beneficial traits in a certain environment
They cause a decrease in the reproduction rate of a species
Within ten years of introducing a new mosquito spray, very few offspring of the targeted mosquito populations were killed by the usual dose of the spray. The best explanation for this is that
consuming the spray caused the mosquitoes to become resistant to it
the spray contaminated the water where mosquitoes lay their eggs
the spray killed organisms that cause diseases for mosquitoes
the variations present in the mosquito population provided resistance to the spray
Once the bioengineered blood vessels made from a plastic-like material are implanted in the recipient's body, they become covered with the recipient's own cells. The advantage of using these bioengineered blood vessels is that
they contain antibodies that prevent an immune response
viruses and bacteria will not infect the cells on these blood vessels
they do not elicit an immune response
the engineered blood vessels can be inherited by future generations
Unlike telephone messages that pass through telephone wires, messages between parts of the body are transmitted by a series of nerve cells that are not in direct contact with each other. The connection between two nerve cells is represented in the diagram below.
Which of the following statements best explains how the message is transmitted, even though these cells are not physically connected to each other?
Cells communicate using chemical messengers between them.
Cells send messages by direct contact with other types of cells.
Nutrients are the primary means of communication between cells.
Ribosomes move from one nerve cell to another.
A saltwater aquarium contained a variety of fish and marine plants. Individuals of a type of small fish from a freshwater stream were accidentally added to the saltwater aquarium. Within an hour, all the fish that were added died, while the saltwater fish remained healthy. The most likely reason the freshwater fish died is that they
Suffered from severe dehydration due to osmosis
Swelled up and died because they absorbed too much water
Could not find freshwater organisms to feed on in the saltwater aquarium, so they died of starvation
Ate all the plants in the aquarium, so there was no more oxygen in the water
An energy pyramid containing green plants and other organisms from a food chain is shown below.
Herbivores are most likely to be found in
only the first level
only the second level
only the third level
the first and second levels
The axolotl, also known as the Mexican walking fish, can regenerate parts of its body, such as a leg or tail.
The regeneration of these parts involves the process of
Fertilization
Mitotic cell division
Selective evolution
Biotechnology
Which of the following options is most likely to control the insect pest and be the least harmful to the environment?
Removing the plants that the insect pest feeds on
Using traps covered with sex hormones that attract the insect pest
Releasing imported insects that prey on the insect pest
Spraying areas with insecticides that affect the insect pest
Which of the following statements about cell function is correct?
Mitochondria transfer energy from organic compounds to form ATP molecules.
Vacuoles are sites of DNA synthesis.
The nucleus stores genes that will later be removed from the cell.
The cell membrane prevents all toxins from entering the cell from its environment.
The image shows the aftermath of a deadly forest fire in California in 2018.
What is the most likely outcome for this ecosystem in the future?
The ecosystem will eventually recover, but it will be very different from the original.
The ecosystem will eventually recover and will be similar to the original.
The entire ecosystem will be re-established after six months.
The ecosystem will not be able to reach a stable state again.
The kittens shown in the picture were born in the same litter.
Kittens from the same litter often have similar characteristics, such as fur texture and markings, because they
were fed milk from the same mother
developed in the same environment
inherited similar genes
were born at the same time
Any damage to which of the following structures will directly affect the nutritional needs of the developing fetus?
Ovary
Testes
Lungs
Placenta
The inability of the body to regulate the pH level of the blood can affect
The enzymes that function within the circulatory system
The ability of red blood cells to fight infection
The ability of white blood cells to transport oxygen to the body
The DNA that controls starch digestion in the circulatory system
Anxiety and stress from tests can trigger many responses in the human body. It can stimulate increased heart rate and breathing, and increased sweating. These physical responses to increased stress are examples of
Competition
Infection
Genetic manipulation
Feedback mechanisms
A self-sustaining ecosystem in a glass tank must include
producers, decomposers, light, and water
herbivores, consumers, decomposers, and water
decomposers, heterotrophs, light, water, and carbon
heterotrophs, water, and carbon dioxide
Scientists examined 39 types of trees from warm and cold regions on Earth, and found that the trees were able to regulate the temperature of their leaves, keeping them around 21°C. This means that the leaves were able to be cooler than their environment in warm regions, but warmer than the environment in cold regions. This is an example of
maintaining homeostasis by responding to environmental changes
controlling the release of carbon dioxide during daylight hours
reducing evaporation for cooling during evening hours
failure to respond to environmental conditions
The diagram represents a food web.
Two of the carnivorous animals represented in this food web are
Deer and mice
Grasses and grasshoppers
Deer and wolves
Toads and snakes
There is a type of marine mollusk along the eastern coast of North America known for its interesting relationship with algae. This mollusk incorporates part of the algae into its tissues. This allows the mollusk to use energy from the sun directly. What structures must the mollusk take from the algae to achieve this?
Nuclei
Mitochondria
Chloroplasts
Ribosomes
What are the three processes that usually lead to the greatest possible diversity of gene combinations?
Mutation, meiosis, and fertilization
Differentiation, mitosis, and fertilization
Cloning, meiosis, and fertilization
Differentiation, mutation, and fertilization
All the genetic information necessary for growth and development in an animal that reproduces sexually is found in
Egg cells only
Sperm cells only
Either sperm cells or egg cells
Zygotes
