Biology Chapter: Cells and Organelles

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Questions and Answers

Which organelle is primarily responsible for producing energy in the cell?

Ribosomes

Cell Membrane

Mitochondria (correct)

Nucleus

What is the primary function of the cell membrane?

Regulates entry and exit of substances (correct)

Synthesizes proteins

Controls cell division

Stores nutrients and waste

Which of the following statements is part of cell theory?

Cells are incapable of performing life activities.

Cells can spontaneously generate from non-living matter.

All living things are made up of one or more cells. (correct)

All cells are identical in structure and function.

What characteristic of living things allows them to respond to changes in their environment?

Sensing and responding Signup and view all the answers

In what way do plant cells differ from animal cells regarding vacuoles?

Plant cells have larger central vacuoles than animal cells. Signup and view all the answers

What is the primary role of DNA in cells?

To control cellular activities and store growth instructions Signup and view all the answers

Why is it advantageous for cells to remain small rather than grow larger?

Smaller cells have a larger surface area to volume ratio, improving nutrient access Signup and view all the answers

Which process describes the movement of water into or out of a cell?

Osmosis Signup and view all the answers

What type of reproduction involves two parents contributing genetic material?

Sexual reproduction Signup and view all the answers

Which of the following is a primary function of cell division in organisms?

Increase in cell numbers for growth and healing Signup and view all the answers

During asexual reproduction, the offspring are

Genetically identical to the parent Signup and view all the answers

What is diffusion in the context of cellular processes?

The movement of gases and nutrients in and out of the cell Signup and view all the answers

How many pairs of chromosomes are organized when a human cell is about to replicate?

23 pairs Signup and view all the answers

What is the primary function of roots in plants?

To anchor the plant and absorb water from the soil Signup and view all the answers

What role do capillaries play in the circulatory system?

They allow gas exchange between blood and tissues Signup and view all the answers

Which of the following statements about photosynthesis is true?

It converts carbon dioxide and water into oxygen and glucose Signup and view all the answers

In which part of the plant does sexual reproduction primarily occur?

Flowers Signup and view all the answers

How do nutrients from digested food enter the bloodstream?

Diffusion through capillaries in the digestive system Signup and view all the answers

What process describes how living organisms access energy?

Cellular respiration Signup and view all the answers

What is one of the major functions of the stem in plants?

Transporting water and nutrients throughout the plant Signup and view all the answers

Which of the following is NOT a function of leaves?

Transporting nutrients to the roots Signup and view all the answers

What is the primary function of the small intestine?

Absorbs nutrients Signup and view all the answers

Which organ is responsible for producing insulin?

Pancreas Signup and view all the answers

How does the stomach aid in digestion?

Mixes food with digestive juices and acids Signup and view all the answers

What is the role of the pyloric valve?

Separates stomach from small intestine Signup and view all the answers

What type of blood vessel carries oxygenated blood away from the heart?

Arteries Signup and view all the answers

Which of the following correctly describes capillaries?

Smallest blood vessels, around one cell thick Signup and view all the answers

Which part of the heart receives blood from the body?

Atrium Signup and view all the answers

How long does it take for a tumor to be felt under the skin, given the typical doubling time of cells?

5 years Signup and view all the answers

Which of the following is considered a carcinogen?

Tobacco smoke Signup and view all the answers

Which of the following methods is NOT used for cancer detection?

Ultrasound therapy Signup and view all the answers

What is the main purpose of regular cancer screening?

To increase the chance of early detection Signup and view all the answers

What type of cell can divide and differentiate into specialized cells?

Stem cells Signup and view all the answers

Which type of stem cells is found in differentiated tissues or organs and plays a role in maintenance and repair?

Adult/Tissue stem cells Signup and view all the answers

What is one consequence of using X-rays in detecting cancer, particularly for pregnant women?

They can cause damage to DNA. Signup and view all the answers

Which of the following foods is recommended to reduce the risk of cancer?

Tomatoes Signup and view all the answers

Which treatment for cancer involves the surgical removal of tumors?

Surgery Signup and view all the answers

What can be attached to an endoscope to help in cancer diagnosis?

Forceps Signup and view all the answers

What characteristic of cancer cells can help medical professionals identify them?

They are often irregularly shaped. Signup and view all the answers

How does chemotherapy specifically target cancer cells?

By killing cells that have short life cycles. Signup and view all the answers

Which of the following statements about specialized cells is true?

They have physical and chemical differences that aid in efficiency. Signup and view all the answers

What is one benefit of studying stem cells in medicine?

They can generate healthy cells to replace diseased ones. Signup and view all the answers

What is the primary function of sweat glands?

Regulate body temperature through evaporation Signup and view all the answers

Which part of the muscular system is entirely controlled by the nervous system?

Skeletal muscle Signup and view all the answers

What is the main role of the skeletal system?

Support and protect the body Signup and view all the answers

How do the respiratory and circulatory systems cooperate?

By facilitating gas exchange in the lungs Signup and view all the answers

What is the significance of neurons in the nervous system?

They send signals as electrochemical waves Signup and view all the answers

What is the primary role of sebaceous glands?

Produce oil to maintain skin health Signup and view all the answers

At birth, how many bones does a newborn baby have compared to an adult human?

300 vs 206 Signup and view all the answers

Which system works with the muscular system to help maintain posture?

Skeletal system Signup and view all the answers

What is the primary role of the lymphatic system?

Protect the body from disease Signup and view all the answers

Which of the following is NOT a function of the integumentary system?

Aids in respiration Signup and view all the answers

Which process occurs when muscles are active during exercise?

Heart rate and breathing increase Signup and view all the answers

What is the function of the endocrine system?

Control growth and metabolism Signup and view all the answers

What are the main components of the nervous system?

Neurons and synapses Signup and view all the answers

Which statement best describes homeostasis?

The maintenance of stable internal conditions Signup and view all the answers

Study Notes

Cells

Living things have a lifespan, grow, reproduce, repair, respond to the environment, need energy, and produce waste.
The cell is the smallest, most basic unit of life, exhibiting characteristics of living things. Most cells incorporate a cell membrane, cytoplasm, nucleus, mitochondria, and vacuoles.
Cell theory asserts all organisms are composed of one or more cells, cells are the basic unit of life, and all cells come from pre-existing cells.

Animal and plant cells

Organelles in both plant and animal cells: Nucleus (controls cell activity, holds DNA), Cytoplasm (jelly-like substance where reactions occur), Cell membrane (regulates what enters and exits the cell), Mitochondria (produces energy), Ribosomes (protein synthesis), Endoplasmic Reticulum (Rough ER synthesizes proteins, Smooth ER synthesizes lipids/detoxifies), Golgi Apparatus (modifies, packages proteins), Vacuoles (store materials), Lysosomes (break down waste), and Cytoskeleton (structure/movement).
Organelles only in plant cells: Cell wall (provides rigidity), Chloroplasts (photosynthesis), and Large central vacuole (supports cell via turgor pressure).
Organelles only in animal cells: Centrioles (organize cell division).

Cell growth and cell division

DNA controls cell activity through instructions for cell growth, structure, and maintenance (DNA is the central control).
Cells need water, nutrients, ions, and oxygen, Smaller cells have high efficiency in nutrient access.
Cell division is crucial for growth, healing, and reproduction. One parent cell generates two identical copies.
Humans have 23 pairs of chromosomes and there are different numbers amongst other species.

Cells and Cancer

Cell division is controlled by checkpoints ensuring cells divide only when needed; these checkpoints prevent excessive or uncontrolled mitosis.
Uncontrolled division of cells causes tumors (masses of growing cells). Benign tumors do not affect surrounding tissues, only through physical crowding. Conversely, malignant tumors affect surrounding tissues; they are cancerous.
Cancer is uncontrolled cell division caused by uncontrolled cell division despite messages to stop, with these cells continuing to grow and divide.

Cell Structure

Cell division is regulated by checkpoints in the nucleus; cells receive messages at these checkpoints to determine if they need to divide, continue, or self-destruct.
Cells do not divide if there are signals from neighbouring cells preventing division, insufficient nutrients, or when DNA is not yet replicated or damaged.

The Cell Cycle

The cell cycle stages: interphase (normal cell processes and DNA duplication), mitosis (DNA division), and cytokinesis (cytoplasm division).
Cells duplicate their DNA in preparation for division during cell cycle interphase
Mitosis is the division of DNA in the nucleus during cell cycle mitosis.
Cytokinesis is the final division of the cytoplasm
Cell cycle checkpoints ensure proper cell division and prevent uncontrolled cell division or disease, such as cancer.
Cancer development can result when cell checkpoints are not followed, leading to uncontrolled cell division, tumor growth, and potential spread.

Other systems

Endocrine: Glands release hormones directly into the bloodstream to regulate diverse bodily functions.
Integumentary: Skin and accessory structures (nails, hair) protect, regulate body temperature, and support sensory receptors.
Muscular: Skeletal, smooth, and cardiac muscles enable movement, maintain posture, and circulate blood.
Nervous: Neurons form a network to regulate body functions and coordinated responses.
Circulatory: Blood transportation system using the heart and blood vessels.
Excretory: Kidneys and related structures filter waste products from blood maintaining water, electrolyte levels.
Reproductive: Organ systems in animals are involved in reproduction.
Respiratory: Facilitates gas exchange (O2 and CO2) between the body and environment.

Digestive System

The digestive system breaks down food into smaller molecules nutrients for absorption.
Organs: Mouth (chewing), Salivary Glands, Esophagus, Stomach, Liver, Gallbladder, Pancreas, Small Intestine, Large Intestine, Pyloric Valve.

Frog dissection

Frogs have a three-chambered heart (two atria and one ventricle).
They use skin and lungs for respiration.
Frog anatomy involves various internal organs.

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Description

Explore the fascinating world of cells in this quiz, covering the essential characteristics of living things and detailed information about animal and plant cells. Delve into cell theory and the roles of various organelles like mitochondria, ribosomes, and lysosomes. Test your knowledge and understanding of the basic unit of life!