Biology Chapter: Characteristics of Life and Cells

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Questions and Answers

What component is absent in bacterial cells that is typically found in plant cells?

Cell membrane

Chloroplasts

Vacuoles (correct)

Cell wall

What is the primary function of a contractile vacuole in unicellular organisms?

Assist in cell division

Regulate water levels (correct)

Store nutrients

Produce energy

Which structure is involved in the photosynthesis process?

Stroma (correct)

Mitochondria

Nucleoid region

Ribosome

Which statement accurately describes prokaryotic cells?

They lack a true nucleus. Signup and view all the answers

What type of organisms contain chloroplasts?

Producers and plants Signup and view all the answers

In what form is energy stored after photosynthesis occurs?

In the bonds of glucose Signup and view all the answers

What distinguishes eukaryotic cells from prokaryotic cells?

Presence of a nucleus Signup and view all the answers

What structure in chloroplasts is modified into sacs called thylakoids?

Inner membrane Signup and view all the answers

What is the primary function of parenchyma tissue?

Performing metabolic activities Signup and view all the answers

Which type of parenchyma is responsible for photosynthesis?

Chlorenchyma Signup and view all the answers

What distinguishes angular collenchyma from other types?

Absence of intercellular spaces Signup and view all the answers

What accumulates in the large central vacuole of older parenchyma?

Anthocyanin or tannins Signup and view all the answers

Which type of collenchyma has more thickening at places adjacent to intercellular spaces?

Lacunar Collenchyma Signup and view all the answers

What substance do xylem parenchyma primarily store?

Starch and fats Signup and view all the answers

What characteristic is not associated with parenchyma tissue?

Lack of metabolic activity Signup and view all the answers

Which type of collenchyma is also referred to as plate collenchyma?

Lamellar Collenchyma Signup and view all the answers

What is a primary assertion of the Cell Theory?

All cells are derived from existing cells. Signup and view all the answers

Which characteristic is essential for an organism to maintain homeostasis?

Regulation of internal environment Signup and view all the answers

What does the concept of 'Omnis cellula e cellula' imply?

Cells derive from pre-existing cells. Signup and view all the answers

Which of the following is true about cellular energy requirements?

Cells utilize energy for various metabolic activities. Signup and view all the answers

What is the significance of organelles such as chloroplasts and mitochondria according to the Endosymbiotic Theory?

They were once free-living organisms. Signup and view all the answers

How do cells contribute to genetic continuity in daughters during division?

Cells transmit their genetic material to daughter cells. Signup and view all the answers

What aspect characterizes prokaryotic cells in contrast to eukaryotic cells?

Prokaryotic cells are generally smaller and simpler. Signup and view all the answers

What is a notable feature of all living cells concerning their chemical composition?

All cells share a similar chemical composition. Signup and view all the answers

What is the primary function of xylem in plants?

Transporting water and minerals Signup and view all the answers

Which of the following is a characteristic of mature xylem cells?

They are primarily dead cells Signup and view all the answers

Which cell type within the phloem performs the role of structural support?

Phloem fibers Signup and view all the answers

What type of cells are responsible for the conduction of prepared food in the xylem?

Xylem parenchyma Signup and view all the answers

Which of the following tissues requires the most energy for transport?

Phloem Signup and view all the answers

What type of cells are tracheids found in?

Xylem tissue Signup and view all the answers

Which of the following best describes the vascular tissue in plants?

It includes both xylem and phloem for transport Signup and view all the answers

Which option accurately defines the function of connective tissue in animals?

Supports and protects organs Signup and view all the answers

What is the role of the G1 phase in the cell cycle?

It is the first intermediate gap stage focused on cell growth. Signup and view all the answers

Which statement accurately describes cytokinesis?

Cytokinesis occurs after mitosis and involves the division of the cytoplasm. Signup and view all the answers

What occurs during the S phase of the cell cycle?

DNA replication takes place. Signup and view all the answers

Which phase is not a part of the cell cycle?

G0 phase Signup and view all the answers

What is the primary purpose of the G2 phase in the cell cycle?

To complete cell growth and prepare for division. Signup and view all the answers

Which of the following best describes the mitotic phase?

It consists of the processes that create two identical daughter cells. Signup and view all the answers

In what way does the cytokinesis process differ in animal cells compared to plant cells?

Animal cells constrict the cell membrane to divide while plant cells form a cell plate. Signup and view all the answers

During which phase of mitosis do chromosomes align at the cell's equatorial plane?

Metaphase Signup and view all the answers

Study Notes

Main Characteristics of an Organism

Composed of cells, the fundamental unit of life.
Requires energy for growth, metabolism, and other functions.
Capable of reproduction, ensuring species survival.
Maintains homeostasis, balancing internal conditions.
Organized structure, facilitates specialized functions.
Engages in growth and development throughout its lifecycle.
Utilizes fluid-filled sacs for storage, especially in plant cells.

Cell Theory

States that all cells arise from pre-existing cells, summarized by "Omnis cellula e cellula."
Cells carry genetic material, transmitted to daughter cells during cell division.
Uniformity in chemical composition across different cell types.
Energy flow and biochemical processes are integral to cell function.

Differences Between Prokaryotic and Eukaryotic Cells

Prokaryotic Cells:
- First type of cells, lack a nucleus and membrane-bound organelles.
- Simplest cellular form, includes bacteria.
- Contain a single circular chromosome in the nucleoid region.
- Surrounded by a cell membrane and cell wall made of peptidoglycan.
- Carry ribosomes for protein synthesis within the cytoplasm.
Eukaryotic Cells:
- Contain a nucleus and membrane-bound organelles.
- Examples include protists, fungi, plants, and animals.

Cell Structure and Functions

Cell Membrane: Regulates entry and exit of substances.
Cytoplasm: Jelly-like fluid where organelles are suspended.
Nucleus: Houses genetic material and controls cellular activities.

Types of Plant Cells

Parenchyma:
- Composed of thin-walled, living cells with metabolic functions like photosynthesis and storage.
- Types include chlorenchyma (photosynthetic) and xylem parenchyma (storage).
Xylem:
- Transports water and minerals from roots to leaves, providing structural support.
- Composed of dead cells, facilitating passive water movement.
Collenchyma:
- Provides flexible structural support, with varied cell wall thickening.

Animal Tissue Types

Epithelial Tissue: Covers body surfaces and cavities, involved in secretion.
Connective Tissue: Supports and protects organs and structures.
Muscle Tissue: Facilitates movement.
Nervous Tissue: Transmits electrical signals for communication.

Endosymbiotic Theory

Proposed by Lynn Margulis, suggesting some organelles originated from free-living cells.
Chloroplasts and mitochondria contain their own DNA, suggesting a symbiotic relationship.

Cell Cycle

Consists of several stages:
- G1 Phase: Initial growth and preparation for DNA replication.
- S Phase: Synthesis phase where DNA is replicated.
- G2 Phase: Final growth phase before cell division.
- G0 Phase: Resting stage for cells that no longer divide.
Mitotic Phase:
- Includes mitosis (the division of the cell's nucleus) and cytokinesis (the division of the cytoplasm).
- Results in two genetically identical daughter cells.

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Description

Explore the fundamental characteristics of living organisms and the cell theory. Learn the distinctions between prokaryotic and eukaryotic cells, including their structures and functions. This quiz will deepen your understanding of biological concepts related to life and cellular biology.