biology exam Flashcards
prophase
Chromatin strands become more tightly coiled and the strands join together called chromosomes
metaphase
spindle fibres attach to the chromosomes at the centromere the tugging action causes the chromosomes to pull apart making a line across the cell
anaphase
the centromere pulls apart the 2 copies of the sister chromosomes
telophase
the chromatids reach the poles and the centrioles and spindle fibers disappear, The nucleus membrane and nucleolus start to form
cytokinesis
the cell splits becoming identical daughter cells
why is crossing over so important
it is important for genetic variation
3 kinds of dominance
Codominance - when both alleles are expressed at the same time (a brown cow with white spots)
incomplete dominance - alleles combine (red cow + white cow = pink cow)
Complete dominance - when only one allele is expressed
recessive traits and how you see them
Recessive traits are shown when a homozygous dominant and a heterozygous have kids there is a chance the recessive traits will be expressed
what is Turner syndrome?
Tuner
Monosomic and XO, Short stature, Webbed neck, Sexually underdeveloped
what is Down syndrome
Downs
extra 21 chromosomes
Almond eyes, flattened face, Weak muscle tone
what is Klenfieder
Klenfieder
XXY
Breast swelling, Sexually immature, Tall stature
genotypes, who can donate and receive type A
Phenotype A
Genotype AA, AO
Donate A,AB
Receive A, O
genotypes, who can donate and receive type B
Phenotype B
Genotype BB, BO
Donate B,AB
Receive B, O
genotypes, who can donate and receive type AB
Phenotype AB
Genotype AB
Donate AB
Receive All
genotypes, who can donate and receive type o
Phenotype O
Genotype OO
Donate All
Receive O
Can a father with blood type A and a mother with blood type B have a child with blood type O? Explain.
If a parent has the genotype AO or BO they have a 50% chance of having a child with O-type blood
the function of the liver
breaks down toxic substances into non-toxic ones
Convert glucose into glycogen
produces biles
the function of the gallbladder
Stores bile and releases it to break down fat in the small intestine
the function of the pancreas
produces insulin
the function of the small intestine
Digestion of lipids and carbs receives chyme and secretions from the gall bladder and pancreas
the function of the large intestine
waste removal and absorption of water and lipids
the function of the stomach
Digestion of protein
Churn food to break it down
Mucus protects the stomach lining
where does it take place?
Mouth - amylase, carbs
Stomach- protein, pepsin
Small intestine- protein lipids and carbs, bile is used to emulsify fat, lipase, proteases and peptidases
The mouth is neutral - So the teeth don’t rot
the pH level of these structures
The mouth
neutral So the teeth don’t rot
Small intestine
8 and neutral, release into the first section to protect the small intestine or You can get ulcers
stomach
acidic and Helps break down food, HCL activates pepsin (inactive HCL won’t digest)
mucus protects the stomach layers
function of the epiglottis
Prevents cough/choking
Covers your airway
what are bicarbonate ions?
Acidic chyme enters if not protected by bile will cause ulcers
what are the valves of the heart
aortic valve
mitral valve
tricuspid valve
pulmonary valve
functions of the heart
Transfers oxygen and carbon dioxide
Distribution of nutrients and waste disposal
Maintain body temperature
Circulation of hormones
locations of oxygenated/deoxygenated blood
Oxygenated blood on the left
Deoxygenated blood on the right
eletorcadiaogram
Tachycardia – heart rate exceeds 100 beats/minute
Brachycardia – heart beats very slowly
First P wave – SA node fires atria contraction
QRS complex – AV node stimulates ventricles to contract.
Final T wave –ventricles relax
what is the formula for cardiac output?
Heart rate X stroke volume
what is vessel elasticity?
A healthy artery expands and recoils when absorbing the shock of systolic pressure
When a person’s arteries harden they do not expand as they should and become weaker and weaker causing high blood pressure
what is blood volume
Blood volume increases when water retention from too much salt causes high blood pressure
what is plasma
the liquid part of the blood
90% water
what is hemoglobin
an iron-containing pigment that increases the capacity of the blood to carry oxygen
what is platelets
Colourless has no nucleus and Initiates blood clotting
what is white blood cells
Destroys invaders with antibodies
what is red blood cells
Transports oxygen and carbon dioxide
the function of the respiratory system
Function of the respiratory system
1. Breathing – the movement of gasses between the respiratory membrane of living things and their
environment
2. Gas Exchange
3. Cellular Respiration
glucose + oxygen -carbon dioxide + water + energy
where does gas exchange happen
In the alveoli, oxygen-depleted blood enters and gets infused with O2 and flows out through the venue to the rest of the body, the CO2 gets defused into the alveoli and will be exhaled into the air.
theory of natural selection
the peppered moths
The peppered moths
When the trees became dark due to the industrial revolution, white or light moths couldn’t camouflage as easily and would get eaten quicker, therefore they couldn’t reproduce and the dark moths reproduced more
homologous vs analogous structures
Homologous
Body parts that are similar in structure but have different functions, these structures are similar because they came from a common ancestor
Analogous
Body parts that have the same function but different internal structures, don’t have any common ancestors
vestigial structures
reduced version of a structure that is not functional but was used in the organism’s ancestor
mimicry
harmless species resemble (mimic) a harmful species so predators will avoid them because they think they are harmful
fitness
The amount of offspring an organism can have
more offspring = more fitness
Prezygotic-temporal
Temporal
Two species that live in the same place but have different mating seasons
hybrid inviability
Hybrid inviability
death in the womb or just after birth
types of selection
Directional Selection
favours phenotypes at one extreme over the other
favours an intermediate phenotype and selects against extreme variants of the phenotype
Disruptive Selection
favours extreme phenotypes rather than intermediate phenotypes
Binomial nomenclature
the system of giving a 2-word Latin name to each species, EX. Homo sapiens
Homo
Mayor group, the organisms belong to
sapiens
Specific species the organisms belong to
lytic vs lysogenic
- Lytic cycle
The host cell is invaded
Virus replicates genetic info
Multiple viruses released and activate
The host cell is destroyed - Lysogenetic cycle
The host cell is invaded, viral DNA attaches to the chromosomes
Remains dormant as a provirus but continues to replicate
Passes through generations without harm
Triggered by nutrient change or stimulus
Virus becomes lytic and causes infection and death of many cells
vascular bundles - structure and function
Transport water and other substances
Contains xylem and phloem
where are stomata and guard cells located and function
Stomata
Pores in the epidermis that allow gas exchange, including water vapour
Found on the underside of the leaf
Found at the bottom of the plant cell
for protection from incests
water loss
maximum photosynthesis
**Guard cells **
Occur in pairs around stomata
Regulate opening and closing of stomata
the pathway of water and dissolved minerals as it is absorbed from the soil and reaches the vascular tissue
Water and minerals being absorbed in soil travel up the tree
Sugar is produced by photosynthesis in the leaf, it travels through the tree and is stored in the roots
mayor location of photosynthesis in leaves
The major location of photosynthesis in leaves is in the palisade cell, they must balance the need to maximize photosynthesis with the problem of drying out
difference in monocots and dicots
Monocots
Veins are parallel
Vascular bundles are scattered
Dicots
Veins are net-like
Vascular bundles arranged in a ring
prezygotic -behavioural
behavioural
behaviours that prevent other organisms. from wanting to mate with organisms preventing fertilization
prezygotic - mechanical isolation
mechanical isolation
Their reproductive organs don’t fit preventing fertilization.
prezygotic-gamate isoaltion
gamete isolation
An egg and sperm from 2 different species meet gametic isolation, the zygote doesn’t form
hybrid breakdown
Hybrid breakdown
Hybrid forms but when these hybrids mate their offspring are weak and sterile
hybrid infertility
Hybrid infertility
cannot have babies /infertile
