CB1: Key Concepts in Biology Flashcards
Define Magnification
The ability to enlarge smaller object’s appearance
What is the formula to calculate magnification using the two lenses?
eyepiece lens x objective lens
How do you calculate magnification based off of image size?
magnification = image size/ actual size
Define resolution
How detailed an image is
What is the difference between a light microscope and an electron microscope?
A light microscope uses light to display enlarged images and has a lower resolution as compared to an electron microscope. An electron microscope uses electrons to display images and has a higher resolving power than the light microscope
What is the limitation of an electron microscope?
You can’t observe living things because samples are placed in vacuums
What is the difference between a prokaryotic and eukaryotic cell?
Eukaryotic cells: cells with a nucleus eg: animal and plant cells
Prokaryotic cells: cells without a nucleus eg: bacteria
What is the role of the nucleus?
- controls the cell and its activities
- contains chromosomes
What is the role of the cell membrane?
- thin bag
- controls what enters and leaves
What is the role of the mitochondria?
Where aerobic respiration occurs
What is the role of the ribosomes?
Makes proteins for the cells
What is the role of the chloroplasts?
- contain chlorophyll
- traps energy from the sun to be used in photosynthesis
What is the role of the cell wall?
- made of cellulose
- supports and protects the cell
What is the role of the vacuole?
- stores cell sap
- helps keep the cell rigid and firm
Define specialised cells
Cells with specific functions/ jobs
What are the adaptations of an egg cell?
- haploid for fertilisation to make a diploid cell
- jelly coat protects the egg and hardens after fertilisation to prevent other sperm cells from entering
- cell membrane: fuses with the sperm cell membrane. also hardens after fertilisation to prevent other sperm cells from entering
- cytoplasm: packed with nutrients to supply fertilised egg cell with energy and raw materials for growth and development of embryo
What are the adaptations of a sperm cell?
- haploid
- streamlined shape: helps it to swim faster
- lots of mitochondria: releases lots of energy
- tail to move
- acrosome: contains enzymes that break down substances in the jelly coat of the egg
What are the adaptations of ciliated epithelial cells?
- cilia covered in cell membrane
- contains strands of a substance that can contract and cause wavy movement