Cells and Systems - 3&4 Flashcards
Cell
What is a cell?
Cells are the basic unit of life
They are the smallest functioning units of life
All organisms are made of at least ONE cell
Largest to Smallest
Order from largest to smallest
Systems → Organs → Tissues → Cells
4 Main Types of Tissue
What are tissues? The 4 Kinds? What do they do?
A tissue is a group of specialised cells
Connective Tissue: supports other tissues (bones, blood, lymph tissues)
Epithelial Tissue: Provides covering and protection (skin, linen or your insides)
Muscle Tissue: includes striated muscles which help move the skeleton , and smooth muscles like the muscle around the stomach
Nervous Tissue: Made of nerve cells called neurons. This tissue carries electrical “messages” around the body
Single-Celled vs Multi-Celled
Single Celled – SIMPLE
- Made up of one cell
- One cell carries out all the functions
- Eg: yeast, Amoeba, Paramecium, some algae
Multi-Celled – COMPLEX
- Made up of many cells
- Rely on many different specialised cells (skin, muscle, etc.)
- Different cells have different functions
Eg: Human // Plants // Animals
Single-Celled can also be classified as “unicellular” which means “one.”
Amoeba
What is Amoeba?
- Unicellular organisms like amoeba often develop spesialised structures to help them perform functions like eating
- Lives in water
- Moves around using pseudopods (false feet or foot-like projections)
- Extend a pseudopod and the cytoplasm fills it. Then they fuse together and form a vacuole (space in cytoplasm) around the food particle
Paramecium
What is a Paramecium? Include Cilia
- Paramecia (plural for paramecium) move swiftly through the freshwater where they live
- Paramecium are covered in hair like structures called cilia
- These cilia move back and forth like oars to move them through the water
Cilia also gathers food by: - Bringing food to an oral groove
Sweeping the food into the cytoplasm - Forming a food vacuole
Cell Structures
What Are Some Cell Structures? What do they Do?
Flagella: Long and tail like.
They whip back and forth to move the cell
Cilia: are short, hair-like structures
They move a cell or move molecules away from a cell
The cilia in your windpipe move harmful particles away from your lungs
Animal vs Plant Cells
Cells, Tissues, Organs
What are Cells, Tissues, and Organs?
Cell: Individual unit of life
Tissue: Group of specialised cells
Organ: Group of tissues that perform a specific function
Organelle
What are Organelles?
Organelles are small structures within the cell that perform specific functions for the cell.
Some organelles are only found in plant cells
Animal vs Plant Cells
Mitochondria
What does this do?
Powerhouse of the cell in which nutrients are digested and converted into usable energy.
The chemical reactions responsible for convertign energy into usable forms
Increase in folds = more surface area = more energy
Responsible for cellular respiration
In both plant and animal cells
Remember: O2 has to do with energy
Animal vs Plant Cells
Cell Membrane
What does this do?
Flexible protective barrier that surrounds the cell gives it structure
Controls what goes in and out of the cell. Selectively Permeable (like drawbridge)
In both plant and animal cells
Membrane: Boundries between 2 areas
Animal vs Plant Cells
Cytoplasm
What does this do?
Fluid of dissolved molecules (water, salts, proteins, etc.) that suspends the organelles
Jelly-like substance
Cyto- means cells
In both plant and animal cells
Animal vs Plant Cells
Nucleus
What does this do?
Brain or “command centre” of the cell “headquarters”
Contains DNA (Genetic Code)
The normal human cells (somatic) contain about 6ft of DNA in the nucleus
In both plant and animal cells
Somatic - relating to the body
Animal vs Plant Cells
Rough Endoplasmic Reticulum
What does this do?
A protein and manufacuring the package system
Ribosomes are attached to the outside making it “rough”
In both plant and animal cells
Animal vs Plant Cells
Ribosomes
What do they do?
Connect amino acids to build proteins that are needed for cell functions
In both plant and animal cells
Animal vs Plant Cells
Golgi Body
What does this do?
Gathers simple molecules to sort and package into more complex molecules
In both plant and animal cells
Animal vs Plant Cells
Lysosomes
What do they do?
Small sacs that destroy unwanted bacteria
Strong enzymes held digests dead/damaged organelles
“Recycling Centre”
In both plant and animal cells
Animal vs Plant Cells
Smooth Endoplasmic Reticulum
What does this do?
Plays an important role in the creation of lipids and hormones
Transports lipids and proteins throughout the cell
No ribosomes attached = smooth
In both plant and animal cells
Animal vs Plant Cells
Centrioles
What do they do?
Two organelles that help the cell divide
ONLY IN ANIMAL CELLS
Oddball
Animal vs Plant Cells
Vacuoles
What does a Vacuole do?
Storage bins where food, nutrients, and waste are kept
Plant cells - usually have one large vacuole
Animal cells - usually have several small vacuoles
Oddball
Animal vs Plant Cells
Cell Wall
What does this do?
Rigid frame-like structure that surrounds the cell membrane
Made of cellulose
Tougher and thicker than cell membrane
Protects and keeps shape of cell]
ONLY IN PLANT CELLS
Oddball
Animal vs Plant Cells
Chloroplasts
What does this do?
Solar panels of the cell
Chloroplasts carry out photosynthesis (energy + H2O + CO2 = O2 and sugars/glucose)
Chloroplasts are filled with discs containing a pigment called chlorophyll
Chlorophill is the reason leaves are green!
ONLY IN PLANT CELLS
Oddball
Most to Least Specialised
Cells → Tissues → Organs → Body Systems
Passive Tansport
What is Passive Transport?
Always moves from high concentration to low concentration
PASSIVE = DOES NOT REQUIRE ENERGY
Diffusion
What is Diffusion
The movement of particles from an area of high conc to low conc
Particles want to acheive an equilibrium within a fluid
Or..
“Diffusion is the net movement of particles from an area of higher conc to lower conc.”
PASSIVE PROCESS
COGNITO
Equilibrium
What is it?
When all the particles in a fluid are spread out evenly
Osmosis
The diffusion of WATER accross selectively permeable membranes
- Basically diffusion but instead of other fluids, it is strictly water
“Osmosis is just a special case of diffusion, aka the diffusion of water molecules
- osmosis is the net movement of water molecules across a partially permeable membrane, from a region of higher conc to lower conc”
COGNITO
Isotonic vs Hypotonic vs Hypertonic Solutions
Isotonic Solutions
What is it?
iso means same
The extracellular fluid has the same osmolarity as the cell… so there will be no net movement of water into or out of the cell
Isotonic vs Hypotonic vs Hypertonic Solutions
Hypotonic Solution
What is it?
hypo means less than
There is LESS WATER in the cell than there should be, so water will diffuse into the cell
Isotonic vs Hypotonic vs Hypertonic Solutions
Hypertonic Solution
What is it?
hyper means greater than
There is way MORE water in the cell than there should be, so the water will move out of the cell to the regoin of higher solute conc.
Permeable
What does this mean?
A membrane that allows all materials to go through
Eg: Cotton shirts are permeable to water
Selectively Permeable
What does this mean?
A membrane that allows only some materials to pass through
Eg: Cell Membranes
Impermeable
What does this mean?
A membrane that doesn’t allow anything to pass through
Eg: Plastic is impermeable to water
Rate of Diffusion
What are some factors that affect the rate of diffusion?
Distance: The longer the distance the particles need to travel, the longer the proccess of diffusion it will take
Temperature: Increased temp = more energy for particles. The particles move faster and in turn, diffuse faster
Characteristics of the Substance: If the particles are too large, it might be more difficult for them to diffuse accross a barrier
Increasing the Difference in Conc: Larger difference in conc = faster the particles will move to acheive equilibrium
DICT Acronym
Active Transport
What is it?
Requires energy to move AGAINST the gradient
Moves from an area of LOW to HIGH conc.
Opposite of Passive Transport
Homeostasis
What is it?
Responding and adapting to your environment
So.. it is the ability for organisms to react to sudden changes in the immediate surroundings
Eg:
- Warm blooded animals - maintain a regular body temp
- Pupils contract when witnessing sunlight
- Regulation of blood sugar levels
- Blood clotting
- Shivers/goosebumps
Heritability and Reproduction
Why are Variation and Diversity Important?
Variation and Diversity allow wild populations to survive, reproduce, and adapt to future environmental changes.
Somatic Cells
What are Somatic Cells? How many chromosomes (pairs) do humans have?
Body cells like skin, muscle, etc. have 100% of your DNA in each cell.
This is known as diploid and is represented as 2n
Has 23 pairs of chromosomes, or 46 in total for human body
They are responsible for Repair, Regeneration, and Growth
Somatic - related to the body
Somatic cells have nothing to do with reproduction, as they have 100% of your DNA. If your partner shared 100% of their DNA with the baby, that would result in a baby with 200% of the parents DNA
Gamete Cells
What are they? How many Chromosomes?
Reproductive or sex cells (sperm -♂- and egg -♀-) that have haploids and is represented with n
Has 23 chromosomes (half of what somatic has) in human gamete cells
Gametes only have 50% of DNA because when 👉👌 happens, your partner has 50% aswell, which adds up to your baby having 100% of both parents DNA.
Chromosome
What is a Chromosome? Somatic/Gamete Cells for offspring
A DNA strand that has been wound up so many times around proteins that it becomes a shape simillar to an “X”
- It is compact because there are so many of them and must be storable within the nucleus
- Unwinds when replicated
SOMATIC CELLS:
-23 chromosomes form mom
-23 chromosomes from dad
= 46 chromosomes in offspring
DNA
What is DNA composed of? What does the acronym stand for?
Deoxyribonucleic Acid
The double helix is composed of phosphate sugar backbone and Nucleotide bases
The following 4 bases make ALL living things:
- Guanine
- Cytosine
- Adenine
- ** T**hymine
G+C // A+T
DNA con’d
GENE
What is a Gene?
Portion of DNA that codes for a specific trait (hair colour, height, skin tone, etc.)
Heritable
A trait that can be passed down to the offspring from the parents
Blood type, certain disorders, etc.
Discrete Variation
Can simply be answered with a “yes”or “no”
Limited possibilities
eg: your can either roll your tongue, or you cannot
Continuous Variation
Varies continuously in a population with no specific yes/no answer.
Range of possibilities
Creasted curves of graphs
How tall are you? yes // That doesn’t make sense
Asexual Reproduction
Binary Fission
What is it?
When a unicellular organism replicates it’s DNA and splits into 2 (it must grow to split)
One parent cell becomes 2 daughter cells
Happens quickly
Daughter cells are clones, no change
The daughter cells will be split by a growing membrane in between, and then pull apart.
Mitosis
What is it?
T for 2
How multicellular organisms undergo cell division to grow and repair.
It must grow in size and double the parents’ DNA to split into 2 daughter cells
Part of Asexual Reproduction
New skin cells are made, or a scab forms
Sexual Reproduction
What happens during Sexual Reproduction?
It results in both parents donating 50% of their DNA to form an offspring
INCREASES variation within a species
Involves gamete cells (egg & sperm) with haploid amount of DNA
Stages and Processes of Sexual Reproduction
What are the Stages and Processes of Sexual Reproduction?
Gametes and haploids are formed by meiosis
Fertilization happens
Forms Zygote
Mitosis
Blastocyst (ball of dividing cells created by fertilized egg)
Mitosis and Differentiation - cells start to specialize based on function
Embryo forms - each somatic cell in the baby has 100% DNA
Fertilization
Process of sperm and egg combining
Diploid
100% of DNA diploid (2n)
Our Cells Divide, so what happens?
1 Chromosome BEFORE mitosis (1 chromotid)
2 Chromosomes after replication (2 chromotid)
1 Chromosome AFTER mitosis (1 chromotid)
Meiosis
Makes gametes by cell replication
Forms 4 daughter cells with half the DNA as the parent cell
Gametes
Sperm (male) and Egg (female)
Haploid
What is a haploid? What is it represented as?
Sex cells that have 50% of your DNA
Haploid is represented as “n”
Diploid
What is a diploid? What is it represented as?
Somatic cells which have 100% of your DNA
“2n”
Dominant
Always expressed when present
Represented with a capital letter
Recessive
Only expressed when no dominant genes are present (two recessive)
Represented with lowercase letters
Gene
Genes vs Alleles
Segmant of DNA that controls a specific trait
Single gene codes for a particular trait
(eg. hair colour gene)
Allele
Genes vs Alleles
A varient of a gene
2 or more alleles bring variations to the trait
Occurs in pairs (one from each parent)
Every choromosome has one (BB, bb, Bb, bB)
Brown hair allele from mom
Blond hair allele from dad
Genotype
Genotype vs Phenotype
Combination of alleles possesed for specific gene
“AA, Bb, cc”
Phenotype
Genotype vs Phenotype
Combonation of observable characteristics/traits
(eg. blonde, brunette, etc.)
Homozygous Dominant
Homozygous vs Heterozygous
Hint: Break it down
Homo = Same
Dominant = Capital Letters
Both alleles are passed onto offspring are dominant
Heterozygous Dominant
Homozygous vs Heterozygous
Hint: Break it down
Heter = Different
Dominant = Capital Letters
One allele passed onto offspring is dominant and the other is recessive
Homozygous Recessive
Hint: Break it down
Homo = Same
Recessive = Lowercase Letters
Both allele passed to offspring are recessive
Are Dominant Traits more Frequent?
No
Think Polydactyly (6 fingers, dominant). It is a common trait, however more people have 5 fingers (recessive)
Incomplete Dominance
This is where neither allele is dominant, and instead, both play a role in the outcome.
What environmental factors affect genetics? Why?
For example, a mother might have a completely normal baby in her womb, but if she goes and consumes a lot of alcohol while pregnant. That alcohol gets into the bloodstream and affects the babies development in brain structures and facial features.
(Fetal Alcohol Syndrome is a prime example)
