Reidmount Science Lessons - 1 to 8

what is biodiversity

the number and variety of species and ecosystems on earth

what are the types of diversity

genetic diversity (genetic variability among organisms), species diversity (the quantity and variety of species), ecological diversity (the range of physical shapes and sizes within an ecosystem)

what is taxonomy and who created it

it is the science of classifying organisms and was made by Carl Linnaeus (also made binomial nomenclature: kingdom, phylum, class, order, family, genus, species)

how are organisms named

by their genus and species

what is dichotomous key

a series of branching, 2 part statements used to identify organisms

what is phylogeny

the science that deals with evolution

what is genetics

branch of biology that studies heredity and variation in inherited characteristics

how do muticellular and unicellular organisms use cell division

MO - growth and repair UO - to reproduce

Chromosomes

inside there is DNA. a gene is a part of the molecule that has info and each gene occupies a different locus (location). chromosomes are found in the nucleus

how many chromosomes do humans have

46

what is mitosis

the process where eurkaryotic cells divide genetic material from the nucleus into 2 new identical nuclei

what are all the steps in order

Prophase, metaphase, anaphase, telophase, cytokinesis

what is prophase

the chromosomes shorten and thicken. centrioles in the cytoplasm separate and move to opposite sides of the cell. centromere anchors the chromosomes to spindle fibers. the nuclear membrane dissolves allowing the chromosome to split into 2 daughter cells

what is metaphase

spindle fibers move and align the chromosomes. chromosomes are pulled to the center of the cell, where centromere aligns across the middle of the cell

what is anaphase

centromeres divide and chromosomes move to opposite sides of cell. chromosomes are pulled by their centromeres making a pattern with the ends of chromosomes trailing behind

what is telophase

chromosomes reach opposite sides of cell and unwind. spindle fibers dissolve and nuclear membranes form. result is 2 daughter nuclei

what is cytokinesis

the cytoplasm divides to make 2 new cells

what is meiosis

it involves the formation of haploid sex cells (aka gametes) that contain egg and sperm. fertilization happens when 2 sex cells produce a zygote (1st cell of new person)

prophase (meiosis)

chromosomes form a homologous pair and crossing over occurs (exchange of genetic material)

metaphase (meiosis)

chromosomes line up on the metaphase plate as homologous pairs

anaphase (meiosis)

members of the pair separate as spindle fibers pull chromosomes apart to opposite sides of cell

telophase (meiosis)

chromosomes are double stranded

cytokinesis (meiosis)

the cytoplasm splits and 2 cells form

errors in meiosis

errors can happen in (meiosis) when the number of chromosomes are higher or lower and can cause genetic disorders like down syndrome

what is an allele

1 of 2 or more alternative forms of a specific gene

who was Gregor Mendel

experimented with garden peas and is the father of modern genetics. he discovered how genes are transmitted and patterns of inheritance

why did Mendel use pea plants

they matured quickly and had 7 pairs of contrasting traits. he wanted to determine which traits were inherited at what frequency

what is a homozygous organism

has 2 identical genes

what is a heterozygous organism

has 2 different genes

what is mendels law of dominance

states that when an organism is heterozygous for a pair of contrasting traits, it shows the dominant trait

what is a genotype

the genetic makeup of a person

what is a phenotype

the outward appearance in regards to a specific characteristic

what is incomplete dominance

when neither allele dominates the other and results in partial expression of both traits

what is co-dominance

when both alleles are expressed fully of produce offspring with a 3rd phenotype

what is a dihybrid cross

cross between 2 organisms that are heterozygous for 2 traits

what is the law of independant assortment

alleles of a trait that are inherited independtly of other traits

who was charles darwin

he studied plants and animals and looked at differences between species in south america and europe. he studied finch species in galapagos islands

charles darwin made what theory for evolution change

1. species change over time

2. the process that makes these changes is called natural selection

when do adaptations occur

when individuals in a population contribute more to the next generation than others

what are the types of selection

1. directional - favours an increase or decrease in the value of a trait

2. stabilizing - against people exhibiting traits that change

3. disruptive - favours 2 or more variations of a trait that differs

4. sexual - different reproductive success caused by variation in getting mates causes sexual dimorphism

what is a mutation (cause of evolutionary changes)

origin of a genetic variation that are random and harmful to the environment

what is gene flow (cause of evolutionary changes)

migration of people or gametes between populations and can add new alleles or alter frequencies

what is genetic drift (cause of evolutionary changes)

random changes in allele frequencies that produce large changes in these frequencies

what is the founder effect (cause of evolutionary changes)

when a few pioneering people colonize a new region and dont have all the alleles in the source population

what is speciation

the formation of a new species by the splitting of existing species

types of speciation

1. allopatric speciation - when populations are separated by a physical barrier

2. sympatric speciation - when the genomes of 2 groups diverse without physical isolation

pre-zygotic barriers - mechanisms that happen before fertilization

behavioural isolation, temporal isolation, ecological isolation, mechanical isolation, genetic isolation

post zygotic mechanism (prevents reproduction in offspring)

zygotic mortality, hybrid in viability, hybrid infertility

what 6 nutrients are essential

carbohydrates, proteins, fats, vitamins, minerals, and water.

what are carbohydrates (main energy source) made of

carbon, oxygen, hydrogen

what do proteins (help to make cells) do and what are they made of

control chemical reactions, movement, transporting oxygen

made of amino acids

what is a vitamin

a compound that organisms need in small amounts (help with growth)

what is a mineral

elements that are needed in small amounts and help with cell processes and repair

what are the 4 main steps to digestion

1. ingestion - taking in nutrients

2. digestion - breaking down food

3. absorption - transfer digested nurtrients to the blood stream

4. egestion - removal of waste

what are the 2 types of digestion

1. physical - large pieces of food are torn and ripped into small pieces by the teeth

2. chemical - enzymes and acids break down the big molecules into smaller molecules

how does digestion work

food enters the mouth and is broken down physically and chemically by the teeth and saliva. the food turns into a bolus and is passed to the pharynx, then the epiglottis, and then the esophagus. the bolus goes through the lower esophageal sphincter and into the stomach. the stomach’s rugae churns the bolus and mixes it with gastric juices. the chime (aka bolus) leaves the stomach through the pyloric sphincter and into the small intestine where absorption occurs. bile breaks down the fats. pancreas secretes its juices. villi in the jejunum maximize the nutrient absorption. the rest of the substance goes to the ileum and then the large intestine. waste goes through the rectum and then the anal sphincter

what is the respiratory system

system that is responsible for the exchange of gasses from the atmosphere

respiratory 3 main parts

1. most respiratory surface

2. bringing air into the body

3. transporting the gasses around the body

what happens when we breathe in

our diaphram contracts and flattens out. our intercostal muscles contract. the lungs expand and increase. a vacuum is created and sucks the air in.

what happens when we breathe out

our diaphram relaxes and domes upwards. our intercoastal muscles relax. our lungs decrease and forces air out.

how does the respiratory system work

air enters through our mouth or nose. hair and mucous filter the air. the air reaches the pharynx and is guided down past the larynx and into the trachea. the trechea has 2 bronchi and they split into bronchioles that make sure air is everywhere in our lungs. the bronchioles have alveoli where gas exchange occurs. then carbon dioxide is released.

what does the circulatory system do

transports oxygen, CO2, nutrients, water, maintains body temperature, and body fluid levels

3 main parts of the circulatory system

1. heart - pumps blood throughout the body and is made of cardiac muscle

2. blood vessels - tubes that blood moves through

3. blood - fluid that transports nutrients and gasses

how does the circulatory system work

the atria is the 2 top chambers that fill with blood that returned from the body/lungs. the ventricle are the bottom chambers that get blood from the atria and pump it. the vena canvae bring oxygen poor blood to the atrium and it flows from the right atrium into the right ventricle. the pulmonary arteries are what that blood is pumped through. the pulmonary veins bring oxygen rich blood to the heart through the left atrium and it flows to the left ventricle. that pumps it to the body through the aorta.

what is blood made of

1. plasma - the fluid portion

2. cells - the solid portion