Biology Chapter 1: Cell Characteristics

Questions and Answers

Which of the following is NOT a basic characteristic of a typical animal cell?

Acquires and utilises energy

Stores hereditary information

Photosynthesis capability (correct)

Able to respond to stimuli

What is the total magnification of a compound microscope based on?

The distance between the lenses

The size of the specimen

Product of objective lens and eyepiece (correct)

The strength of one lens

Who observed the first living cells and referred to them as 'animalcules'?

Rudolf Virchow

Robert Hooke

Felix Dujardin

Anton Van Leeuwenhoek (correct)

Which of the following is the second postulate of the cell theory?

Cell is the basic structural and functional unit of living organisms Signup and view all the answers

Which part of a compound microscope is responsible for adjusting the view of the specimen?

Adjustment Knob Signup and view all the answers

What type of microscope has multiple lenses?

Compound Microscope Signup and view all the answers

Which of the following scientists contributed to the cell theory?

Schleiden and Schwann Signup and view all the answers

What limitation does a simple microscope have compared to a compound microscope?

It is limited to one lens only Signup and view all the answers

What is the main role of the nucleus in a eukaryotic cell?

To control growth and metabolic activities Signup and view all the answers

What is primarily found in the cytoplasm of a eukaryotic cell?

Aqueous mixture containing organelles Signup and view all the answers

What structure forms the outermost layer of animal cells?

Cell membrane Signup and view all the answers

What layer constitutes the basic structure of the cell membrane?

Phospholipid bilayer Signup and view all the answers

Which characteristic best defines a selectively permeable membrane?

Permits only certain molecules to cross Signup and view all the answers

Which of the following components is NOT part of the cytoplasm?

Nuclear material Signup and view all the answers

What is one of the primary functions of transport proteins in the cell membrane?

To facilitate the transport of substances Signup and view all the answers

Which type of membrane allows all particles to pass freely?

Freely permeable membrane Signup and view all the answers

What type of cells undergo mitosis?

Somatic cells Signup and view all the answers

What is the result of a single round of mitosis?

Two diploid daughter cells Signup and view all the answers

How many nuclear divisions occur during meiosis?

Two Signup and view all the answers

What happens to the chromosome number during meiosis?

It is reduced to half Signup and view all the answers

Which of the following is correct regarding daughter cells produced by meiosis?

They are haploid and genetically diverse Signup and view all the answers

What happens to a cell placed in a hypertonic solution?

The cell loses water and shrinks. Signup and view all the answers

What describes an isotonic solution in relation to a cell?

It has the same concentration of solutes as the cell. Signup and view all the answers

What is the primary function of the rough endoplasmic reticulum (RER)?

Protein and enzyme synthesis. Signup and view all the answers

Which statement correctly describes the Golgi body?

It packages materials synthesized in the cell. Signup and view all the answers

What is a key structural characteristic of mitochondria?

Double-membrane with infoldings called cristae. Signup and view all the answers

What role do chloroplasts play in plant cells?

They convert sunlight into chemical energy through photosynthesis. Signup and view all the answers

Which statement about smooth endoplasmic reticulum (SER) is correct?

It is involved in lipid and steroid synthesis. Signup and view all the answers

What is one of the functions of the stroma in chloroplasts?

It stores ribosomes and enzymes. Signup and view all the answers

What characterizes a freely permeable membrane?

It allows all molecules to pass through without any resistance. Signup and view all the answers

What type of transport requires energy to move molecules against their concentration gradient?

Active transport Signup and view all the answers

Which of the following correctly describes passive transport?

Moves molecules down their concentration gradient without energy. Signup and view all the answers

What role does the cell wall play in plant cells?

It maintains rigid structure and provides mechanical strength. Signup and view all the answers

What is the primary composition of the cell wall in plant cells?

Cellulose Signup and view all the answers

In a hypotonic solution, what happens to a cell?

The cell gains water by osmosis. Signup and view all the answers

Which type of molecule is primarily transported through passive transport?

Small molecules like oxygen and carbon dioxide Signup and view all the answers

What structure in fungi serves a similar purpose to the cell wall in plants?

Chitin Signup and view all the answers

Study Notes

Basic Characteristics of Cells

Cells store hereditary information, reproduce, acquire and utilize energy, and are sites for various biochemical reactions.
They are capable of responding to stimuli.

Cell Discovery

Robert Hooke examined cork and identified "cells," which are dead plant cells.
Anton Van Leeuwenhoek improved microscope design and observed the first living cells, termed "animalcules."

Cell Theory

Formulated by Schleiden and Schwann, modified by Rudolf Virchow, stating:
- All living organisms are made up of one or more cells.
- The cell is the basic structural and functional unit of life.
- All cells arise from pre-existing cells.

Microscopes

Instruments designed to magnify small objects, revealing details invisible to the naked eye.

Simple Microscope

Consists of a single lens with magnification limited to one lens.

Compound Microscope

Utilizes multiple lenses; total magnification is the product of objective and eyepiece lenses.

Types of Cells

Cells are categorized into two main groups based on complexity.

Components of a Eukaryotic Cell

Nucleus: Contains DNA organized into chromosomes; controls growth and metabolism; surrounded by a nuclear envelope.
Cytoplasm: Jelly-like substance within the cell membrane, mainly comprised of water, salts, proteins, and organelles; site of most biochemical reactions.
Cell Membrane: Flexible and selectively permeable; outermost layer enclosing the cell.

Cell Membrane

Composed of phospholipid bilayer and embedded proteins.
Functions include enclosing cell components and regulating substance passage.

Permeability

Types of membranes:
- Impermeable: No particles pass.
- Selectively permeable: Specific molecules can cross.
- Freely permeable: All molecules can cross without resistance.

Types of Transport

Active Transport: Movement against the concentration gradient using cellular energy (ATP).
Passive Transport: Movement down the concentration gradient without energy expenditure.

Cell Wall

Plant Cells: Outermost layer providing rigidity, composed of cellulose.
Other Organisms:
- Fungi: Made of chitin.
- Algae: Consist of cellulose.
- Bacteria: Comprised of peptidoglycan.

Cells in Different Solutions

Hypotonic Solution: Higher water concentration outside; cells gain water.
Hypertonic Solution: Lower water concentration outside; cells lose water.
Isotonic Solution: Equal water concentration; no net movement of water.

Cell Organelles

Organelles: Subcellular structures with specific functions.

Endoplasmic Reticulum (ER)

Rough ER: Ribosomes attached; synthesizes proteins and enzymes.
Smooth ER: No ribosomes; synthesizes lipids and steroids.

Golgi Body

Composed of membrane-bound sacs (cisternae); packages and transports materials synthesized in the cell.

Mitochondria

Double-membrane organelle with its own DNA; site of ATP production.

Chloroplasts

Present in higher plants; contains thylakoids and stroma for photosynthesis.

Cell Division

Mitosis

Occurs in somatic cells; results in two diploid daughter cells; chromosome number remains the same.

Meiosis

Occurs in germ cells; results in four haploid daughter cells; chromosome number is halved after two nuclear divisions.

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Description

Explore the fundamental characteristics of cells in this quiz. Learn about the functions and roles of a typical animal cell, including energy acquisition, reproduction, and response to stimuli. Test your understanding of cell discovery and its importance in biology.